# Hotwire PWM Regulator for Mag D body, JM-PhD-D1



## JimmyM (Dec 16, 2008)

I'm starting this thread to see about interest and introduce my version of the Hotwire regulator. This is a spin-off of the design work that Alan_b, wquiles, myself, and others have been working on. The basic theory, design, software, etc have been developing for a while over in this thread. HERE

My version will be similar to the JM-SST in that, it will reside under a KIU base and use PWM. Other than that, this is a true PWM regulator.
I haven't begun power testing at high levels yet.

I'd like to see what thoughts you folks have regarding this.
SInce this design will be incorporated into an existing Mag switch. You have 2 options.
1) The internal circuit is completely dead when off and it will only leak as much current as the MOSFET itself will allow. That's in the area of a few nano or micro amps. However, you're limited to just ON or OFF operation.
2) The internal circuitry is live (but will sleep). This will leak more current due to the voltage sampling divider and the circuitry using some small amount of current. In the area of a few hundred micro amps. But this will allow things like multiple levels.

Also, there is the subject of adjustability. The circuit is reporgrammable and the source code is available. So you can have me program it for certain voltages before sending it out or you can reprogram it yourselves if you're feeling adventurous.
There is another possible option. I'm going to work on a way to add an adjustment pot to the regulator. This way, you can adjust your own voltage.

To Do List:
Run high power tests with 30V FET
Run high power tests with 40V FET

OK, so that's it. I'd like to open the floor for discussion.

UPDATE 1/6/09:
An onboard pot to adjust voltage will be used. This will maintain it's setting even if you change packs.
The 30V version looks good. I'm waiting on a 40V FET (that would be used in the actual design) to run high power tests. I have another 40V FET but that one is too large to use in the end design.
I have run tests using the 64623 and 64625 bulbs with the 30V FET with 29.4V input and 12VRMS output. Peak current on the FET is about 21 Amps. Tests have run as long as 3+ hours with no issues. I have more parts on the way to test 40V FET version.
We (Alan, Will, and I) have noticed an inductive "kick" that applies greater then supply voltage to the FET when it turns off. I'm investigating possible ill effects caused by this. Thus far I have seen none.


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## drew2001 (Dec 16, 2008)

Hi Jimmy,

I'm absolutely interested. Wanted to bump your post up and look forward to others expressing participation as well. I'd say for my app it would be # 1 as I only use the mag623 (so far) and have yet to go into higher watt outputs. Looks like the chances for upping the outputs in a D cell size mag is going forward. I also like the idea of owner operator adjustable pot option for the v regulator... options options fun stuff.

Will this next gen board have a slow start option as well?

For those reading about this for the first time, I'll add that Jim has been great at working his magic and timely fulfilling the orders. I've been in contact with his design revisions on my own JM-SST board and been happy with the outcomes. 

Below is a link to my first attempt at installing the circuit board in my mag623

https://www.candlepowerforums.com/threads/186715

Just wanted to post success stories in confidence. Looking forward to yours, Alan's, Will's and others efforts.

Thanks again. :thumbsup:


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## JimmyM (Dec 16, 2008)

It WILL have a softstart feature. Sorry I forgot to mention that part.

In the next few days I'll be doing some high power testing with the FET I plan to use. I'll start with the 5761 and move up to the 64623 and 64458.
I'd like to see if the smaller FET can handle the high current of the big bulbs.


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## JimmyM (Dec 16, 2008)

Another question for you folks.
What is the highest voltage Mag bodied mag? Would it exceed 35V?


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## donn_ (Dec 16, 2008)

Better ask Lux that question. :devil:


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## Metatron (Dec 16, 2008)

JimmyM said:


> Another question for you folks.
> What is the highest voltage Mag bodied mag? Would it exceed 35V?


i have an elle II with a 400watt globe just waiting for an appropriate switch, so 40v would be right on.


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## JimmyM (Dec 16, 2008)

donn_ said:


> Better ask Lux that question. :devil:


True. I think I remember someone using a 36V bulb. Hmmmm. That "may" be outside the realm of possibility for this unit. But we'll see. The ing is... If I can use a different regulator internally, that frees up more room, making more room for a bigger FET.
Of course, I have to see how popular the programming ability is for folks. If most people just want them set and be able to tune the voltage via a pot, then I can gain some room for a bigger FET.


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## Metatron (Dec 16, 2008)

JimmyM said:


> True. I think I remember someone using a 36V bulb. Hmmmm. That "may" be outside the realm of possibility for this unit. But we'll see. The ing is... If I can use a different regulator internally, that frees up more room, making more room for a bigger FET.
> Of course, I have to see how popular the programming ability is for folks. If most people just want them set and be able to tune the voltage via a pot, then I can gain some room for a bigger FET.


now ur talking great idea a pot!


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## Raoul_Duke (Dec 16, 2008)

I'm interested.

I'd like to think I could re-program thins, but I would be happier on a fresh pack, and measuring V bulb, and using a pot.

Where would the pot be? would we have to drill a hole in the kiu, or could it be done by removing the rubber boot of the switch.

Also would it be possible for a couple of wires to be hidden under the boot for measuring V bulb.

The tailcap could be unscrewed for the leakge issue, and the multi lever is good for usefull vs insane output.

I'd like to be able to get a full run without heat concernes, but have the option of going back to full power when required.

Would be nice if it switched on at full blast ( ok maybe a few mseconds SS) and then ramp down.

Whatever way you do it I'm interested. ( edit = Sold :twothumbs )


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## JimmyM (Dec 16, 2008)

Raoul_Duke said:


> I'm interested.
> 
> I'd like to think I could re-program thins, but I would be happier on a fresh pack, and measuring V bulb, and using a pot.
> 
> ...


For the ON/OFF version, no modding of the guts of the switch are required. You would just solder a wire from the top if the switch to the pad on the regulator. Just like the JM-SST. So a pot under the rubber switch boot would require a lot more modding. The pot for this version would be accessed via a hole in the kiu base. To measure voltage, however, you will need a True RMS voltmeter since the voltage to the bulb will be a PWM/Square wave.
The multi mode version would require that the switch me made momentary. This is pretty easily done.


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## Alan B (Dec 16, 2008)

JimmyM said:


> For the ON/OFF version, no modding of the guts of the switch are required. You would just solder a wire from the top if the switch to the pad on the regulator. Just like the JM-SST. So a pot under the rubber switch boot would require a lot more modding. The pot for this version would be accessed via a hole in the kiu base. To measure voltage, however, you will need a True RMS voltmeter since the voltage to the bulb will be a PWM/Square wave.
> The multi mode version would require that the switch me made momentary. This is pretty easily done.



*NOTE* - DC RMS meters with the proper characteristics are not common, and are not required.

Measurements can be done with an averaging DVM and a calculation. It is probably better to recommend this technique than getting or using a DC RMS meter, since most inexpensive RMS meters won't do it properly, and folks who have or buy RMS meters won't be happy if they buy one and it does not work for them on DC RMS.

*Procedure:*

Measure Vbatt and Vbulb mean and calculate Vrms, or measure Vbatt and assume a desired Vrms and compute the Vbulb mean to adjust to. This is documented in the design thread and in the program source (copied here):

* RMS Calculations
*
* VbulbRMS = sqrt(VbattDC * VbulbMEAN) # to see what you have
*
* VbulbMEAN = VbulbRMS^2 / VbattDC # to set a desired value

One tricky thing is to adjust the output voltage without losing the low battery voltage protection. The calibration needs to be correct for the protection to work properly, so changing the calibration is not really what one wants to do with the output voltage pot. It might make more sense to have a voltage adjustment pot that merely put a voltage into a chip pin that was a "request" input, and use this to control the desired output voltage. The calibration would be separate, and the low battery voltage would be unaffected by the adjustment.

Alternately, develop a "one button interface" program rather than a pot for the interface.

Lots of choices.

*-- Alan*


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## JimmyM (Dec 16, 2008)

You're absolutely right, Alan. I forgot about that.

Also, the IRLR/IRLU7843 runs the 84458 at 19.9V RMS on a 25V DC supply with barely any warmth. I had to touch the tab with the skin just back from my fingernail to detect it at all. An infrared thermometer would be nice. I'll be testing the 64623 on 16V later.
Regarding heat. The original JM-SST didn't have any heat sink at all. This board design has a much larger copper area to dissipate heat if it accumulates. 2 oz copper and 16 thermal vias to a copper pour on the bottom of the board. Similar but smaller type of thing on the FET driver.
If I can manage to get rid of the programming header I might be able to make room for the mighty IRF2804(40V) or IRF3206(60V). Then 500+ watt regulated Mag mods might be possible. Of course I would have to leave that up to LuxLuthor capable hands to test. He he he.


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## JimmyM (Dec 16, 2008)

Alan B said:


> *
> * One tricky thing is to adjust the output voltage without losing the low battery voltage protection. The calibration needs to be correct for the protection to work properly, so changing the calibration is not really what one wants to do with the output voltage pot. It might make more sense to have a voltage adjustment pot that merely put a voltage into a chip pin that was a "request" input, and use this to control the desired output voltage. The calibration would be separate, and the low battery voltage would be unaffected by the adjustment.
> 
> Alternately, develop a "one button interface" program rather than a pot for the interface.
> ...


All true. It's a fine balance between operator simplicity and functionality. That's kind of what I'm trying to feel out here. I like the "request pin" input idea. I've mostly been messing around with FP7. simple ON/OFF with regulation and softstart. The low battery protection would be cool if I can fit all that stuff on the board. Because the programming header would still be required to set the low voltage shutdown. So many options, so little space. I'd hate to have to fit an additional pot. We'll see.


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## SafetyBob (Dec 16, 2008)

OK, Jimmy, here it goes:

I would like a simple on/off regulated, softstart thingy for a 623 setup first. Now, I want you so set it up, I will tell you what battery setup I will use.....niMh or emoli. All I need to do is install the thing and done....ready to go. 

I think if we keep it simple, limited to three or four bulbs for now, it would be best for you for inventory and runs of forty or fifty would be feasible for you to keep up with you would be stuck with stuff you can't sell. 

Now, if it would be possible for the low voltage shutoff, then you would be even more of the man that you already are in most of our opinions. But if it complicates the design so that it becomes a big problem to fit into the switch or assembly, then lets forget it........it would be nice though!

Now, the future. I know this is for [email protected], but you know there is a small crowd of us crazy ones contemplating how to fit aircraft landing lights into a cheap lantern assembly.....we would appreciate something for that 400, 600, 800 or 1000 watt light too. But we can talk about that later after the [email protected] situation is solved or into production.

I appreciate all your work on this. It's really up to you if you want to manufacture a complete switch assembly or just a board that most of us can install ourselves. 

Bob E.


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## JimmyM (Dec 16, 2008)

SafetyBob said:


> OK, Jimmy, here it goes:
> 
> I would like a simple on/off regulated, softstart thingy for a 623 setup first. Now, I want you so set it up, I will tell you what battery setup I will use.....niMh or emoli. All I need to do is install the thing and done....ready to go.
> 
> ...


It's not a matter of bulb set-up per se. It's just a voltage issue. Set it to what ever voltage you want, then it will hold that voltage as long as the battery voltage is at least that high. So it should be able to run any bulb between 6V and 30V provided it doesn't draw more than ~12A (I'm guessing there, but testing so far looks promising). I can't make a whole bunch of different versions. So everyone is going to be the baddest thing I can package into a 30mm round board. The WA1185 bulb will be driven by the same unit that drives the 64623. Just set differently.
The low voltage cut off is possible, but it would have to be implemented via software programming. There just isn't enough room on the board for 2 pots AND a programming header.
All but one of the components in the new design, thus far, is included in the PhD Proto board. It's just the FET driver that's different. I'm going to pick a couple up and teset it out. The driver on the proto board can pass 9A, the one I've selected for the D Mag, can only do 2A. So it may affect switching speeds, but not much. The switching transients are already like a wall on the scope. Testing will tell the tale.

Regarding the future. I'm already cursing the 30mm board for its size. The ones I build for the Lantern bodied lights will be chock full of stuff. Low voltage cut-off, multiple settings, adjustable via a pot (Set max regulated voltage via a pot, and the 3 settings will be something like 75%, 88%, and 100% of set voltage or whatever). I even found a chip that can do per cell voltage monitoring for up to 10 li-ion cells. And it will have a nice beefy driver than can handle dual or quad or more FETs and still drive it properly. 100 Amps would be manageable. They'll be much smaller runs and thus more expensive, but that's the way things go.

But keep the ideas coming, guys.


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## LuxLuthor (Dec 17, 2008)

Jimmy,

I think there are only a few that would be willing to take all the steps to make >250W work. There are issues of reflector size, host, heat, battery source/charging, practical illumination, run time, etc. that limit what is worth doing. 

Beyond the 150W you are using over 12A; on high current--NiMH or safe chemistry 18650, run time sucks. Actually, above 50W run time sucks. I guess what I am saying is for the developments/testing to satisfy regulation >30V is hard to justify.

For some the POT solution ala AWR's HotDriver example is the only thing that would be workable. When I spoke with him, most people ONLY wanted a set, programmed driver that was setup for a particular bulb, and didn't want to even understand his simple POT adjustments. 

For others having the program header would allow much more adaptability & flexibility. You don't need a POT (or 2 POTs) if you are willing to set program instructions...as long as the instructions on what/how to change is made simplistic "paint by numbers." I think many would be happier with program header.

Perhaps having both choices available (POTs or Header) is the wisest?


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## donn_ (Dec 17, 2008)

I'm gonna pipe in on this thread as well, although I already listed this "wish" on Will's M6 thread.

I'd like to see this regulator built into a battery sleeve, rather than a light or a battery pack.

The reason is my choice of cells. I use A123s as much as possible, in both sizes.

I'd like to see a programmable battery sleeve system, which can be made to fit a variety of [email protected] tube-lengths, and can regulate the lower voltage A123 cell format. I'd like it to take 26650 A123 cells or Emoli 26670s.

In [email protected] tubes, it would be a sleeve system.

In [email protected] tubes it would be positioned at either the front or rear of a stack of cells.

In fatter [email protected] tubes, it would be an insert which would interface with cell packs/holders of 18650 A123s.


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## JimmyM (Dec 17, 2008)

donn_ said:


> I'm gonna pipe in on this thread as well, although I already listed this "wish" on Will's M6 thread.
> 
> I'd like to see this regulator built into a battery sleeve, rather than a light or a battery pack.
> 
> ...


A regulated battery holder. That would require a lot of fab work that I just don't have the equipment or knowhow to do. I've mentioned, in passing, to Lux, that he and I might do a kind of "project". He builds packs, I build the regulators. He lives very closeby. The downside of building it into a pack, is that either it's ALWAYS on or you have to remove the pack to slide a tiny switch to shut it down. And you would still have to contend with the stock switch components.


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## JimmyM (Dec 17, 2008)

I just ran some tests with a 64623. 15.7V RMS output from an 18.1 V source. The FET barely warmed up at all. No heat sink. 9.8 amps RMS measured.
No problem. I'll have to build a parallel bulb rig to more heavy load the FET.
So it looks like I've found my FET for the driver.
Now if we can work out the details.
My first instinct would be to leave out the low bat shudown, keep the programming header.
I'm still on the fence regarding the pot.


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## donn_ (Dec 17, 2008)

The ultimate would not be a pack, but a holder.

Imagine a delrin sleeve in segments; A front endcap to interface with the light source, and a tail endcap to interface with the tail-spring. 

Build the regulation into either the front or rear endcap, whichever works better.

Stick as many segments as needed in between the two, to hold the cells.


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## leukos (Dec 17, 2008)

That would be ideal, but I imagine this regulator needs both Vbatt+ and Vbatt- to operate which means a dedicated, fixed size battery pack. Well, maybe it could work if the center rod carried the Vbatt+ or - and it screwed together in segments, but that would only work with smaller diameter batteries such as AA.


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## donn_ (Dec 17, 2008)

leukos said:


> That would be ideal, but I imagine this regulator needs both Vbatt+ and Vbatt- to operate which means a dedicated, fixed size battery pack.



Or dedicated ends to a variable length battery sleeve?


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## leukos (Dec 17, 2008)

It would seem a little flimsy, but I suppose you could have a wire the length of a Mag 6D connecting the two endcaps?


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## donn_ (Dec 17, 2008)

I can think of at least a couple of other options.

Wired sleeve segments, with the wire safely buried in the delrin, and connecting segment to segment.

How about using the body as the connection?


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## SafetyBob (Dec 17, 2008)

Donn brings up an excellent suggestion that may be best for version two. I agree a board say half an inch by two inches could have all sorts of stuff populated on it with simple trim to fit wires and only a center delrin or something provided with it or directions on how to make it sit safety in the battery section. Again, looking at good directions for drilling holes through the switch to the KIU socket. 

However, back to main subject here. Jimmy, I am thrilled the first test went will with a 623. If it's easy for us "idiots" to do the pot thing with an ordinary meter, I would suggest going that way. Maybe a separate run for the programing head....which would require X, Y, and Z. Don't know how many would be willing to get more crap for the old lights considering we have boxes full of stuff now. 

Low cutoff, if it is to much, then let's forget we even brought it up for a round board. 

My two cents for now......

Bob E.


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## JimmyM (Dec 18, 2008)

I can't start several runs. Each would take a different board design.
The pack idea is a good one, but not within the scope of this project.
I'd like to stick to the "under the KIU" design, for the time being.

I have to look into the details of the pot idea. It could be possible to overload the ADC on the Tiny85 if you had set it for a lower voltage pack then moved to a much higher voltage pack without setting the pot. But even if you dial back the pot all the way, it will see what it thinks is a lower voltage pack and could blow the bulb straight off. I like Alan's idea of a voltage output setting pot and a fixed voltage sampling system.
I'll have to ping him on that idea.


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## cnjl3 (Dec 20, 2008)

My vote is for:
- under the KIU
- softstart
- low voltage cutoff
- Adjustment pot if possible

your solution below will run the 64625 with no problems with whatever battery solution a user has in mind? NIMH, Li-ion, li-mn, emoli..etc?

This is a great project.



JimmyM said:


> I just ran some tests with a 64623. 15.7V RMS output from an 18.1 V source. The FET barely warmed up at all. No heat sink. 9.8 amps RMS measured.
> No problem. I'll have to build a parallel bulb rig to more heavy load the FET.
> So it looks like I've found my FET for the driver.
> Now if we can work out the details.
> ...


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## JimmyM (Dec 20, 2008)

It will a 64625 with no problems.
I tested, so far...
64458: 25V input, 19.9V output. Bulb didn't last long.
64623: 17-18V input, 15.5V output.
No heat problems with either. It warmed up just enough to touch it and say "hmm, I think it feels warmer than before".
I'm going to try testing with a pair of 64623s in parallel just to really push it.
I have to get some more parts to be able to test it using the exact components that would go into the "production" unit.


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## wquiles (Dec 20, 2008)

JimmyM said:


> It will a 64625 with no problems.
> I tested, so far...
> 64458: 25V input, 19.9V output. Bulb didn't last long.
> 64623: 17-18V input, 15.5V output.
> ...



I think that because the FET is switching so fast through the linear region (you are using the FET driver in yours, right?) that the heat in the FET will not be a problem 

Will


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## JimmyM (Dec 20, 2008)

wquiles said:


> I think that because the FET is switching so fast through the linear region (you are using the FET driver in yours, right?) that the heat in the FET will not be a problem
> 
> Will


That's why I like the FET driver concept. It relieves the uC of the load of switching the gate and it can drive the gate rather hard. I'm using the 5V uC output to control the FET driver which is switching the gate with 12V. I found that adding a 510 Ohm gate resistor didn't change the switching characteristics at 244Hz, but it reduced transients on the 12V buss. The FET driver I'm using on the PhD-Proto board can pass a peak current of 9A. The one I'm looking at for a 30mm board is a SOT-143 package and can only pass 2A peak. So I might be able to remove the gate resistor in the final design. I have to test that. Right now I'm hunting for a tiny 12V fixed regulator for the 30mm design. 12V can drive the gate of even big 10V gate FETs. I'll be testing high current bulbs with just a 5V gate drive to see if I can reduce the component count. But then I'll have more transient noise on the 5V buss that feeds the uC. That's bad.
Since the focus of this design will be for <30V use, I have more to choose from.


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## Mr Happy (Dec 20, 2008)

JimmyM said:


> ...more transient noise on the 5V buss that feeds the uC...


Maybe separate traces back to the common 5 V source would be better...?

I found this interesting article with discussion on layout techniques: Basic Switching-Regulator-Layout Techniques
 
It's talking about MAXIM IC's, but contains much of general relevance.


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## JimmyM (Dec 20, 2008)

Thanks for the link. I've been attempting to include those priciples in me design, but will keep it more in the forefront of my mind while designing. Also, bypass, bypass, bypass caps. I may include different bypassing for the uC as well. I have to do some testing though.


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## Bullet Bob (Dec 20, 2008)

I too would like to see a finished ready to go regulator that I can install with a minimum of fuss. On most of my light projects I know what bulb / battery combo I want to run but can't always hit the target voltage without a regulator so this is what a lot of us have been looking for. If the voltage set point has to be done in advance on your end thats fine with me and I have no problem getting different units for different applications. If it can be made to be settable on our end that would be nice but not absolutly neccesary. Some bulb/ battery combos are languishing for the lack of a good regulator. For example I think theres a lot of potential in the IRC bulbs being driven at the right voltage but hitting the 20-21 volts on batteries alone is difficult but they offer good output with less amp draw than other bulbs which translates into more run time. Right now for me to hit the 20-21 volt range I need two extensions on an Ele II body and a series/ parallel battery pak with some dummy cells. I could reduce this whole thing down to just eight batteries in series with a regulator. So yes I'm interested.


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## JimmyM (Dec 22, 2008)

As long as the regulator is set for a certain voltage, it doesn't matter what voltage the pack is, as long as it is at least as high as the bulb voltage you want to use. So you can run your 5761 on the same pack as your Mag623 uses. Since the voltage was set for the 5761, the higher voltage of the 64623 pack will just add runtime.
I'm doing some programming learning to use a different chip than wquiles and alan_b are using. It will operate the same, but the chip itself is smaller and allows for more future feature expansion.
If I can talk LuxLuthor into a project with me, we might be able to build packs with lots of different options.


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## wquiles (Dec 22, 2008)

JimmyM said:


> As long as the regulator is set for a certain voltage, it doesn't matter what voltage the pack is, as long as it is at least as high as the bulb voltage you want to use. So you can run your 5761 on the same pack as your Mag623 uses. Since the voltage was set for the 5761, the higher voltage of the 64623 pack will just add runtime.
> I'm doing some programming learning to use a different chip than wquiles and alan_b are using. It will operate the same, but the chip itself is smaller and allows for more future feature expansion.
> If I can talk LuxLuthor into a project with me, we might be able to build packs with lots of different options.



Jim - actually, since I need to move to a surface mount part anyway for the PhD-M6, I might as well rather use the same chip as you are planning on using, even if I don't quite use all of the features/pins on the first go-around. Please email me what you come up with - that would be great 

Will


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## JimmyM (Dec 22, 2008)

I can post it here so others are up to speed too.
I'm planning on using the Tiny84. Normally, it's a 14 pin DIP (6 more pins to mess with), but also comes in a QFN20 package. It's leads are on the edges but don't stick out like a 8SOIC. It's only 4mm square. It has the same memory as the Tiny85, but has more pins available for other things. It can also do up to 16 bit PWM. That's a bit extreme, but it can do it.
I've been talking a bit with Alan, but he seems satisifed with the Tiny85. There's nothing wrong with the Tiny85. It works just fine. I just want wanted a smaller footprint. However, rewriting the code is less than a simple thing.
So, I'm digging in and following Alan's footsteps with the different chip.
Doing the basics. Get it to read a button, then get it to generate a PWM signal, then read an ADC, etc.


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## LuxLuthor (Dec 22, 2008)

JimmyM said:


> As long as the regulator is set for a certain voltage, it doesn't matter what voltage the pack is, as long as it is at least as high as the bulb voltage you want to use. So you can run your 5761 on the same pack as your Mag623 uses. Since the voltage was set for the 5761, the higher voltage of the 64623 pack will just add runtime.
> I'm doing some programming learning to use a different chip than wquiles and alan_b are using. It will operate the same, but the chip itself is smaller and allows for more future feature expansion.
> *If I can talk LuxLuthor into a project with me, we might be able to build packs with lots of different options.*



:wave: I'll check with you after the holidays.


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## Alan B (Dec 22, 2008)

JimmyM said:


> I can post it here so others are up to speed too.
> I'm planning on using the Tiny84. Normally, it's a 14 pin DIP (6 more pins to mess with), but also comes in a QFN20 package. It's leads are on the edges but don't stick out like a 8SOIC. It's only 4mm square. It has the same memory as the Tiny85, but has more pins available for other things. It can also do up to 16 bit PWM. That's a bit extreme, but it can do it.
> I've been talking a bit with Alan, but he seems satisifed with the Tiny85. There's nothing wrong with the Tiny85. It works just fine. I just want wanted a smaller footprint. However, rewriting the code is less than a simple thing.
> So, I'm digging in and following Alan's footsteps with the different chip.
> Doing the basics. Get it to read a button, then get it to generate a PWM signal, then read an ADC, etc.


 
Lots of great ideas in this thread, nice to see all the interest in this. My goal when starting this was to have several hotwire regulators available, and this is the final step toward that goal. :twothumbs

The Tiny84 is fine, it is just a bit of a redesign and will delay the project a couple of months (my estimate). It is up to Jim as this is his project, but I would produce the first product with the existing design (or close to it) and leave the upgrade for later, but that's just me. I have a very strong motivation to KISS (keep it simple), especially for something like a flashlight.

-- Alan


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## SafetyBob (Dec 22, 2008)

Jimmy, one last quick question. 

So you are telling me I can get a regulated thing from you (and hopefully setup and adjusted already) so I can run my WA1185 bulb for an hour (just imagine please) with some crazy battery pack made up of "x" amount of NiMH or Emoli batteries.......meaning that if my 1185 likes 12.472VDC (for example), the board could be adjusted to maintain that even though I might have a 15, 18, 20.4, all the way up to 30VDC battery pack? Correct? 

If you tell me yes, just tell me where I need to send the paypal money to. I am ready. I am about ready to get a new battery pack full of Emoli batteries to harvest just for fun....ok, they will really be for a really nice [email protected] and [email protected] setup. What could be better that those two lights for a nice set of incan [email protected]? 

We wil talk landing light regulator boards later, but for now.....simple [email protected] will do. This will be the answer to my prayers!!!!

Bob E.


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## JimmyM (Dec 23, 2008)

SafetyBob said:


> Jimmy, one last quick question.
> 
> So you are telling me I can get a regulated thing from you (and hopefully setup and adjusted already) so I can run my WA1185 bulb for an hour (just imagine please) with some crazy battery pack made up of "x" amount of NiMH or Emoli batteries.......meaning that if my 1185 likes 12.472VDC (for example), the board could be adjusted to maintain that even though I might have a 15, 18, 20.4, all the way up to 30VDC battery pack? Correct?
> 
> ...


That's exactly what I'm saying! Nifty huh? The regulator design reads battery voltage hundreds of times a second and calculates if the duty cycle needs to increased or decreased to meet the desired voltage.

It's not accurate to 0.001 volts. A several hundredths, maybe a tenth, is more like it. But if you want 11.5 volts, it should be able to hold 11.4-11.6 without any problems. Accuracy worsens as the battery voltage gets higher. But I'm working on that too.


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## JimmyM (Dec 23, 2008)

Alan B said:


> Lots of great ideas in this thread, nice to see all the interest in this. My goal when starting this was to have several hotwire regulators available, and this is the final step toward that goal. :twothumbs
> 
> The Tiny84 is fine, it is just a bit of a redesign and will delay the project a couple of months (my estimate). It is up to Jim as this is his project, but I would produce the first product with the existing design (or close to it) and leave the upgrade for later, but that's just me. I have a very strong motivation to KISS (keep it simple), especially for something like a flashlight.
> 
> -- Alan


I'm all for KISS! But I think the Tiny84 is a better chip and should have some development done for it. The "core engine" of all these designs has been the Tiny85 so far for a lot of reasons, But I think the 84 should step in for several designs.
Moving to 10-bit calculations will be slower (we quadruple the voltage resolution), but we only really need to loop through that code several 10s of times per second. The battery voltage isn't going to change all that quickly. In fact, It won't help to loop through more than 244 times per second. If it takes 1000 clock cycles to go through the code, that means it will loop 8000 times per second. I read last night that it takes the ADC 13 clock cycles to read. That's pretty quick.
I've been reading about ADCs, Timers, debouncing, and interrupts. The power of the 8MHz Tiny84/85 is essentially using a sledgehammer to kill a fly. I'll be getting a couple/few of the Tiny84s in 14-DIP configuration to do some development.

I've written some pseudo code to help organize my thoughts.
Basically I'm converting to volts instead of ADC/PWM counts. The "regulation code" calculates the PWM value required each time. The softstart loops through a VRAMP value increasing it by some value VRAMPSTEP each time, until the VRAMP >= VTARGET. I'm doing division as little as possible.


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## wquiles (Dec 23, 2008)

JimmyM said:


> I'll be getting a couple/few of the Tiny84s in 14-DIP configuration to do some development.


Count me in if you want to do a variation on the development board for the Tiny 84 - having the extra I/O pins easily accessible would be outstanding!. I would not mind at all splitting the cost again with you as it helps us both 

Will


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## JimmyM (Dec 23, 2008)

I was going to just breadboard it.
But I can have boards made for $33 each. I can change the design of the Tiny85 board (as a copy) and make it for the Tiny84 14-DIP. The 20QFN is just a different package, same pins/ports, etc.
What about this...
Since My design might be better suited to having an ADC on one pin versus your design being better laid out using another pin. I can build the board such that ALL pins can be manually assigned to external resources.
(Although this would complicate programming, since the different functions would have assigned to different pins). Maybe it's not a good idea.
It would be a sort of bread board but just for the I/O pins.
Power and programming would be wired as before. There would be the same set of jumpers for power supply and FET driver, etc.
I could include a different FET driver. The one that I've chosen for use in my designs. That way we could more closely approximate the performance in a "production build" environment.
Would you trust my judgement in choosing and FET driver and 5V regulator in SMD packages to include on the board?

The "breadboard" part would just be where you jumper your different voltage dividers, FET drive, buttons, switches, etc to whatever I/O pin you want.
I can use pin sockets for the voltage divider resistor positions and the jumper points. Would you want a DIP switch set on the board?

Of course this could only be done after some testing of the programming connections, etc.
I like the idea, but let me get some breadboarding done first to develop a working schematic. After that, perhaps a formal "proto" board could be done. But once those boards are cut, that's it. Unless we build this thng like a real breadboard.
Functional groups that we use wire jumpers to connect things. Of course then it would be just a task specific breadboard.


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## wquiles (Dec 23, 2008)

JimmyM said:


> I was going to just breadboard it.
> But I can have boards made for $33 each. I can change the design of the Tiny85 board (as a copy) and make it for the Tiny84 14-DIP. The 20QFN is just a different package, same pins/ports, etc.
> What about this...
> Since My design might be better suited to having an ADC on one pin versus your design being better laid out using another pin. I can build the board such that ALL pins can be manually assigned to external resources.
> ...


No problem - sounds like a great plan indeed. Like before I would buy 2-3 of them again this time.




JimmyM said:


> I could include a different FET driver. The one that I've chosen for use in my designs. That way we could more closely approximate the performance in a "production build" environment.
> Would you trust my judgement in choosing and FET driver and 5V regulator in SMD packages to include on the board?


I definitely trust you, but I still want the ability (like with the current board) to by-pass the FET driver completely, as for the lower voltages/power in the PhD-M6 the FET driver might not be required.





JimmyM said:


> The "breadboard" part would just be where you jumper your different voltage dividers, FET drive, buttons, switches, etc to whatever I/O pin you want.
> I can use pin sockets for the voltage divider resistor positions and the jumper points. Would you want a DIP switch set on the board?


Yes, please, the more options for pluging different parts the better. Don't pick a DIP switch yet, but it would be awesome to have the holes/pads for it - for the PhD-M6 some folks wanted/prefer a rotary switch to the DIP switch, so I would hate if the board is hardwired to only one option for the bulb/voltage selection.




JimmyM said:


> I like the idea, but let me get some breadboarding done first to develop a working schematic. After that, perhaps a formal "proto" board could be done. But once those boards are cut, that's it. Unless we build this thng like a real breadboard.
> Functional groups that we use wire jumpers to connect things. Of course then it would be just a task specific breadboard.


I trust your instincts on this one. You have my email, so just let me know how I can be of help and if you are ready to start ordering parts so that I can Paypal you funds 

Will


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## JimmyM (Dec 23, 2008)

wquiles said:


> No problem - sounds like a great plan indeed. Like before I would buy 2-3 of them again this time.


I'll see what I can come up with. Flexible, but not rediculous.


wquiles said:


> I definitely trust you, but I still want the ability (like with the current board) to by-pass the FET driver completely, as for the lower voltages/power in the PhD-M6 the FET driver might not be required.


Of course. JUMPERS GALORE!! 


wquiles said:


> Yes, please, the more options for pluging different parts the better. Don't pick a DIP switch yet, but it would be awesome to have the holes/pads for it - for the PhD-M6 some folks wanted/prefer a rotary switch to the DIP switch, so I would hate if the board is hardwired to only one option for the bulb/voltage selection.


OK. I'll just put some pads for a 8-DIP. There are rotary ones available that can encode BCD (Binary Counting Digits). A 6-pin package does 3-bits (8 total selections) 


wquiles said:


> I trust your instincts on this one. You have my email, so just let me know how I can be of help and if you are ready to start ordering parts so that I can Paypal you funds
> 
> Will


I'll see what I can do.
I'm envisioning...
1) 2 positions for a 12V reg (LM7812 or similar, and my favorite LT3014B. Jumper selectable
2) 2 positions for a 5V reg (MIC5213 and another to chosen for your design range). Jumper selectable.
3) Std spacing on Power connections for binding posts.
4) Strip socket receptacles for different resistor values.
5) A couple of additional voltage dividers with pin sockets
6) Pin sockets for all I/O pins
7) A DIP switch socket
8) FET driver (MIC4416, very tiny SOT-143 package). It would be a shame not to include it.


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## JimmyM (Dec 23, 2008)

I forget where I announced it, but the IRLR7843 drives the 64623 using a 12V gate with no issues.
ALSO, it can use a 5V gate driving the 64623 with no heat issues. I had it running for about a half hour with no real heat at all.
So, Will. You can use this FET in your design with 5V gate drive.
What is max pack voltage? I found a 5V reg that is an SOT-23 and can do up to 35V, but I'd like to look for one that has better ground current and LDO performance.

I may have found just the regulator you need. The TI TPS71550. 24Vmax, 5V out, 50mA, SC-70 package. It's SUPER tiny. You'll probably need a little extra capacitance in the 5V buss, but that's no big deal. You can get a 2.2uF/10V cap in a 0603 package, and 10uF/10V cap in an 0805 package. Both X7R temp coefficient.


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## wquiles (Dec 23, 2008)

JimmyM said:


> I'll see what I can do.
> I'm envisioning...
> 1) 2 positions for a 12V reg (LM7812 or similar, and my favorite LT3014B. Jumper selectable
> 2) 2 positions for a 5V reg (MIC5213 and another to chosen for your design range). Jumper selectable.
> ...


Excellent :twothumbs




JimmyM said:


> I forget where I announced it, but the IRLR7843 drives the 64623 using a 12V gate with no issues.
> ALSO, it can use a 5V gate driving the 64623 with no heat issues. I had it running for about a half hour with no real heat at all.
> So, Will. You can use this FET in your design with 5V gate drive.
> What is max pack voltage? I found a 5V reg that is an SOT-23 and can do up to 35V, but I'd like to look for one that has better ground current and LDO performance.


Cool - yet another FET that we can use. Right now we are looking at 3x LiIon, so about 12 volts max 

Will


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## JimmyM (Dec 23, 2008)

Read my update above. I found a 50mA regulator (24Vin, SC-70, 3.2uA quiescent current at 50mA). So your regulator can even be used with "extended packs". An SC-70 is about the size of an 0603 SMD device (plus legs). More room on the board.


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## Starlight (Dec 23, 2008)

Jimmy,
I would like to have at least a couple of the 40v models. I have a Mammoth and an Elle II. Both will hold 8X18650 batteries, so they can start out well over 30v. Factory set, programmable, or pot adjustable all will be fine. I wish you could up your 12 amp limit however, since some of these bulbs can run right at that number.

Will you supply the entire, drop-in, unit (switch, KIU socket and your driver) or will we need to get the parts and assemble them ourselves?

Last but not least, I would like a driver for my Larry12K. This won't have to be 30mm form factor, but needs to be 40v and capable of at least 25 amps.

I really appreciate your efforts. These will make feeding my lights much easier!

Harry


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## JimmyM (Dec 23, 2008)

Starlight said:


> Jimmy,
> I would like to have at least a couple of the 40v models. I have a Mammoth and an Elle II. Both will hold 8X18650 batteries, so they can start out well over 30v. Factory set, programmable, or pot adjustable all will be fine. I wish you could up your 12 amp limit however, since some of these bulbs can run right at that number.
> 
> Will you supply the entire, drop-in, unit (switch, KIU socket and your driver) or will we need to get the parts and assemble them ourselves?
> ...


40V in a 30mm board might be a bit of a trick. Crossing the 30V barrier means using a different FET that has a higher resistance. Maybe if I can find the right FET.

EDIT: What bulb did you have in mind?
No sweat for the L14K (and it's kin). It will be a 60V/40A beast with many options for adjustability.


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## Starlight (Dec 23, 2008)

In your first post, you talked about a 40v option. I am using 8x18650 with a 64657 and 7x18650 with a 64655. All my other bulbs would be no problem.

The 60v/40A beast sounds perfect.

You didn't address the question about providing drop-in modules.


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## JimmyM (Dec 23, 2008)

Starlight said:


> In your first post, you talked about a 40v option. I am using 8x18650 with a 64657 and 7x18650 with a 64655. All my other bulbs would be no problem.


Yes. I have an FET spec'd out that will do 40V, but it has higher resistance then the IRLR7843 for the 30V version. It can handle the voltage, but maybe not the current due to lack of proper heat sinking.



Starlight said:


> The 60v/40A beast sounds perfect.


I'm specing components now. It should be able to drive several external FETs, so current handling isn't an issue, and the IRFS3206 can handle 60V.



Starlight said:


> You didn't address the question about providing drop-in modules.


Oh, yeah. Sorry about that. It would be a 30mm board that would be assembled by the buyer with his/her (his/HER, yeah, who am I kidding.) mag switch and KIU. Assembly is just too time consuming with all of my other projects in the works.


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## SafetyBob (Dec 24, 2008)

OK then, one 1185 module, one 623 module, and lastly one for a 625. 

That will so it for me........

That would be [email protected]

My paypal finger is getting very, very....let's just say it's ready to GO!!!

Bob E.


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## cnjl3 (Dec 24, 2008)

Yeah, 625 solution for me paypal locked and loaded.



JimmyM said:


> Oh, yeah. Sorry about that. It would be a 30mm board that would be assembled by the buyer with his/her (his/HER, yeah, who am I kidding.) mag switch and KIU. Assembly is just too time consuming with all of my other projects in the works.


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## pertinax (Dec 24, 2008)

I had some of Winny's regulators a few years back. They were awesome when they worked, but inevitably they died. Still, the concept is awesome and I'm in for more.

JimmyM, I've got one of your soft starters, and if it's that simple to install you'll sell boatloads of regulators. I want to make my Mag85 run on 16 AA Eneloops! Or lithiums, or whatever. 

Pertinax


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## JimmyM (Dec 31, 2008)

pertinax said:


> I had some of Winny's regulators a few years back. They were awesome when they worked, but inevitably they died. Still, the concept is awesome and I'm in for more.
> 
> JimmyM, I've got one of your soft starters, and if it's that simple to install you'll sell boatloads of regulators. I want to make my Mag85 run on 16 AA Eneloops! Or lithiums, or whatever.
> 
> Pertinax


Yup. It's the same basic idea, mounting-wise, as the JM-SST.
I'm just in the phase of working out the design/board layout to optimise things. How can I free-up more board space for a bigger FET? Can I reduce component count for simplicity? What component values will work best? Can I use a 40V FET and still get decent thermal performance at 12A or so?


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## Starlight (Dec 31, 2008)

Jimmy,
Do you have any idea when you might produce these boards? I'm not trying to push you, just trying to get some long range planning done.

Thanks,
Harry


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## donn_ (Dec 31, 2008)

Any plans (down the road) for one of these which will fit a C-Mag tube?


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## SafetyBob (Jan 1, 2009)

Jimmy, while your enjoying your new year, once again I have been trying to think clearly in order for you zero in on our needs. 

[email protected]: ordinarly we would use FM's 9xAA battery holder to keep things from blowing up, that with additional runtime from FM's 12xAA holder would really make a very, very nice flashlight with significant brightness with our choice of average runtime or extended battery options.......since we have discussed Emoli's before, 3x would be normal, and 4x would offer the average flashaholic a stunning performer with great runtime too. 

Basically copy cat the above with the 623. 

Bob E.


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## JimmyM (Jan 2, 2009)

SafetyBob said:


> Jimmy, while your enjoying your new year, once again I have been trying to think clearly in order for you zero in on our needs.
> 
> [email protected]: ordinarly we would use FM's 9xAA battery holder to keep things from blowing up, that with additional runtime from FM's 12xAA holder would really make a very, very nice flashlight with significant brightness with our choice of average runtime or extended battery options.......since we have discussed Emoli's before, 3x would be normal, and 4x would offer the average flashaholic a stunning performer with great runtime too.
> 
> ...


That shouldn't be a problem. You just set the voltage you want, and let the regulator work out the rest. It really doesn't have anything to do with the bulb itself. If you set it for 11.1V (for example), you can run any bulb you want on 11.1V (assuming it doesn't blow on 11.1V). The pack can be just about anything over 11.1V and under 30V. I don't have testing results on small filaments with large battery-to-bulb voltage differentials. Small filaments have less thermal mass, they MAY be more affected by a large voltage differential. I think I'll tap Lux for a little testing.

Lux, if you're monitoring this thread...
Would you mind testing an 1185 on 12V input/11.1V output against another 1185 using the same 11.1V output, but this time with a 24V input?
I can PP you to defray some of the bulb costs.


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## Alan B (Jan 2, 2009)

JimmyM said:


> That shouldn't be a problem. You just set the voltage you want, and let the regulator work out the rest. It really doesn't have anything to do with the bulb itself. If you set it for 11.1V (for example), you can run any bulb you want on 11.1V (assuming it doesn't blow on 11.1V). The pack can be just about anything over 11.1V and under 30V. I don't have testing results on small filaments with large battery-to-bulb voltage differentials. Small filaments have less thermal mass, they MAY be more affected by a large voltage differential. I think I'll tap Lux for a little testing.



If some of the parts (such as the FET) are rated at 30V maximum, that means that 30V should NEVER be exceeded. One of the things we have seen is that a lot of older regulators die after awhile (we have not seen that with this new design, but we don't have the same level of experience with it yet either). It is important to derate the operating voltage enough that these maximums are never exceeded. As we now know, there is a slight inductive kick apparently from the filament that spikes the voltage up as the FET goes off. There is still some work to be done in the spike area, but in any case we need some headroom for this and other voltage excursions to occur and still stay below maximum ratings.

Note also that using an FET driver may make this spike go even higher, but it also becomes much shorter and harder to see, so we might think it is getting better when it is in fact getting more dangerous for the FET. We have not seen this happen, but is that because it is not happening, or because it is harder to measure? The amount of energy to be dissipated is constant (the inductive energy in the filament), so dissipating it in a shorter time due to faster switching requires a higher voltage...

Based on the unknowns I would recommend a substantial safety margin on the component voltage ratings. For example, derate 30V parts to something on the order of 20V. This will make the system far more reliable, which is a good quality in a flashlight.

-- Alan


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## Alan B (Jan 2, 2009)

SafetyBob said:


> Jimmy, while your enjoying your new year, once again I have been trying to think clearly in order for you zero in on our needs.
> 
> [email protected]: ordinarly we would use FM's 9xAA battery holder to keep things from blowing up, that with additional runtime from FM's 12xAA holder would really make a very, very nice flashlight with significant brightness with our choice of average runtime or extended battery options.......since we have discussed Emoli's before, 3x would be normal, and 4x would offer the average flashaholic a stunning performer with great runtime too.
> 
> ...





JimmyM said:


> That shouldn't be a problem. You just set the voltage you want, and let the regulator work out the rest. It really doesn't have anything to do with the bulb itself. If you set it for 11.1V (for example), you can run any bulb you want on 11.1V (assuming it doesn't blow on 11.1V). The pack can be just about anything over 11.1V and under 30V.
> 
> .



The regulator will compensate for the pack voltage, as Jim indicates.

However the protection voltage should be adjusted for the battery pack. Protecting the batteries is useful and important, especially so folks can use things like unprotected Li-Ions. The protection circuits in the cells are problematic for these high current applications, so using the protection in the regulator makes a lot of sense.

-- Alan


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## JimmyM (Jan 2, 2009)

Alan B said:


> However the protection voltage should be adjusted for the battery pack. Protecting the batteries is useful and important, especially so folks can use things like unprotected Li-Ions. The protection circuits in the cells are problematic for these high current applications, so using the protection in the regulator makes a lot of sense.
> 
> -- Alan


Oh, yes. I forget about onboard voltage protection.

I've yet to test the DPAK 40V FET at high power. My order just shipped from Digikey, so I'll be testing that one as my preferred FET.
I've been zooming in on the rising and falling edges during testing. While testing the 30V FET I have now, and the 40V FET I'm expectiing, I'll capture some waveforms while driving things at real world voltage and currents. I think I have an extra IRLU7843 for testing. Maybe I'll test one driving an 64623 at 30V In/14V out, and see what happens.


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## donn_ (Jan 2, 2009)

donn_ said:


> Any plans (down the road) for one of these which will fit a C-Mag tube?


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## JimmyM (Jan 2, 2009)

donn_ said:


>


Perhaps, but mounting would be difficult. The KIU bipin mount for C cell mags leaves nowhere to mount any electronics. It would definitely have to have components on both sides of the board. But how would it be mounted/wired within the light?


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## donn_ (Jan 2, 2009)

I wonder if there's a way to modify AW's C-Mag softstarter.


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## Alan B (Jan 2, 2009)

donn_ said:


> I wonder if there's a way to modify AW's C-Mag softstarter.



Probably make more sense to start from scratch and design for a full switch replacement, which is what AW did. Rather costly to start with a $75 part.

We already have a D mag design that works that way (full switch replacement), and it uses all fullsize parts. Shrinking it to C size would probably not be too hard.

I just received a set of D Li-Ion cells. Nearly 5AH (measured about 4500 mAH as I recall). Now those are going to work nicely in a regulated 3D [email protected] I think I'll stick with D myself.

-- Alan


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## JimmyM (Jan 2, 2009)

donn_ said:


> I wonder if there's a way to modify AW's C-Mag softstarter.


I suppose it's possible. But, per Alan's comments above, it would make more sense to design a new switch body. To use the existing switch body would be quite difficult.


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## donn_ (Jan 2, 2009)

I agree. I hadn't factored in the initial cost of the AW part.

The reason I'm hot on Cs is the fact I prefer A123 cells to Emoli or IMRs. They have most of the benefits, and other than lower capacity, no downsides. And they can be recharged so much faster, the difference is night and day.

I can easily run them in D tubes, but I also prefer the form factor of the D tube.


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## JimmyM (Jan 3, 2009)

JimmyM said:


> Maybe I'll test one driving an 64623 at 30V In/14V out, and see what happens.


I'm testing a 64623 on 29.3V input with a 12V setpoint.
There is an inductive kick at shutoff. It shoots up to 39-40V. Schottkys across the FET and bulb have no effect. As we've seen during development. The FET is getting warm, but no overly so. I can easily hold it between my fingers indefinitely. I think it's the fact that it is carrying quite a bit of current while ON.
From Lux's tests...
64623 on 12V = 8.8A Therefore -> 1.364 Ohms.
29.3V/1.364Ohms = 21.48 Amps while in the ON state.
It's been running for 10 minutes so far. I'll let it run for another hour or so and see what happens.
Note: This is using an FET driver and 5V gate drive. Not 12V.


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## Alan B (Jan 3, 2009)

JimmyM said:


> I'm testing a 64623 on 29.3V input with a 12V setpoint.
> There is an inductive kick at shutoff. It shoots up to 39-40V. Schottkys across the FET and bulb have no effect. As we've seen during development. The FET is getting warm, but no overly so. I can easily hold it between my fingers indefinitely. I think it's the fact that it is carrying quite a bit of current while ON.
> From Lux's tests...
> 64623 on 12V = 8.8A Therefore -> 1.364 Ohms.
> ...



Great test. Would be interesting to know how it does without the driver. That voltage kick is endangering the 40V FET. Probably not acceptable the way it is, no margin. Might be ok on 24V or 25V, but there may be more peak voltage than the scope is seeing.

The voltage kick should be L* di/dt. So it should be worse with the driver since dt is smaller. L and di are fixed. All you can control is dt. Need to slow it down a little to reduce the voltage kick.

-- Alan


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## JimmyM (Jan 3, 2009)

Alan B said:


> Great test. Would be interesting to know how it does without the driver. That voltage kick is endangering the 40V FET. Probably not acceptable the way it is, no margin. Might be ok on 24V or 25V, but there may be more peak voltage than the scope is seeing.
> 
> The voltage kick should be L* di/dt. So it should be worse with the driver since dt is smaller. L and di are fixed. All you can control is dt. Need to slow it down a little to reduce the voltage kick.
> 
> -- Alan


2 hours later and the 30V FET isn't letting up. It's still just quite warm. That's all. No problems. Hmmmm. I'll see how the 40V FET works out when it gets here. But the 30V FET seems to be holding on just fine.

Why wouldn't a schottkey have any effect? It should shunt that kick back to the bulb positive.

EDIT check that "no effect" part.
Below is a cap of the scope. 10V/div, 1uS/div.
Green = WITH BAT42W Schottky diode (5nS reverse recovery)
Red = No Diode.





Also, I switched to a 64625 and the trace was EXACTLY the same.


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## Mr Happy (Jan 3, 2009)

JimmyM said:


> Below is a cap of the scope.


I don't see a pic...?


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## JimmyM (Jan 3, 2009)

Here's another cap. Both with schottkys.
10V/div, 1uS/div
Green = 64625
Red = Automotive type 1157 dual filament (both filaments driven)


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## wquiles (Jan 3, 2009)

JimmyM said:


> 2 hours later and the 30V FET isn't letting up. It's still just quite warm. That's all. No problems. Hmmmm. I'll see how the 40V FET works out when it gets here. But the 30V FET seems to be holding on just fine.
> 
> Why wouldn't a schottkey have any effect? It should shunt that kick back to the bulb positive.
> 
> ...



If you recall my early scope shots on th email PhD thread also showed the schottkey had no effect for me either (at least nothing significant) 

Will


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## JimmyM (Jan 3, 2009)

wquiles said:


> If you recall my early scope shots on th email PhD thread also showed the schottkey had no effect for me either (at least nothing significant)
> 
> Will


I remember. It didn't change things for me either. I just can't believe it has no effect. I HAD to try it again.


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## JimmyM (Jan 4, 2009)

Alan, The 40V FET I found has a logic level gate and has 3.8 mOhm Rds(on) at 5V. I thought it was a standard gate. This could allow me to reduce component count on the board.
I've also fould a fixed 30mA/5V linear regulator that has a Max Vin = 45V. Unfortunately, Digikey doesn't stock it, so I'm looking into samples from the Mfg and lot pricing.


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## Alan B (Jan 4, 2009)

That provides good voltage margins. 5V gate is good, especially for those high current 6V bulbs with low voltage packs.

The voltage spike is not important as long as it does not exceed ratings of devices. Adding parts to control it is probably not desirable in these tight and cost sensitive applications.

Did you try driving the high power bulb without the FET driver? Is the driver really required?

-- Alan


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## JimmyM (Jan 4, 2009)

Alan B said:


> Did you try driving the high power bulb without the FET driver? Is the driver really required?
> 
> -- Alan


I haven't tried it yet. Maybe I'll try this afternoon.
I'll get scope caps of the turn-on / turn-off. I just can't quantify it, but I really want to use the FET diver. I suppose I'm going to have to prove it to myself that it isn't needed. I just feel like I need to isolate the AVR from the gate drive duties.


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## Alan B (Jan 4, 2009)

JimmyM said:


> I haven't tried it yet. Maybe I'll try this afternoon.
> I'll get scope caps of the turn-on / turn-off. I just can't quantify it, but I really want to use the FET diver. I suppose I'm going to have to prove it to myself that it isn't needed. I just feel like I need to isolate the AVR from the gate drive duties.



It is just an engineering tradeoff, it would be good to know what the cost/benefit is. As long as we don't exceed the per pin current rating of the micro it should not hurt the micro to drive the FET, and as long as the FET dissipation and voltage ratings are not exceeded, it should not hurt the FET. I would expect with the really high current bulbs there might be a need for it to keep the FET power dissipation down, but it would be good to figure out where the extra drive is required. These FETs are so incredibly high gain and low on resistance they can do amazing things when driven directly with the Micro. This performance was not available some years ago.

-- Alan


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## JimmyM (Jan 4, 2009)

Test conditions: 20V in, 12VRMS out, 64625 bulb.

This is the OFF transition (voltage measured across the FET)
10V/div, 5uS/div
Green = FET Driver with 510 Ohm resistor in series with gate
Pink = AVR direct drive with 68 Ohm resistor in series with gate.





This is the ON transition (voltage measured across the FET)
10V/div, 5uS/div
Green = FET Driver with 510 Ohm resistor in series with gate
Pink = AVR direct drive with 68 Ohm resistor in series with gate.




I know the FET Driver has a 510 Ohm resistor in series, but the AVR with the 68 Ohm resistor (calculated in Dev thread) shows a nice drive (slew rate-wise) , but the voltage spike at turn off holds at the "kick voltage" for longer.
I'm going to turn things up a bit and see what happens.


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## JimmyM (Jan 4, 2009)

Here's the scope...
Conditions: 29.4Vin, 12VRMS out, 64625 bulb. AVR direct drive.

10V/div, 5uS/div



The kick is still there, as before. But the 30V FET I'm using is getting a 41.6V Vds whack every time it's shut off. But it's not complaining.
Also, it's been running like this for the last 15 minutes with no heat problems. I.d say it's a little warmer than before, but nothing serious so far. I hope not, it's my last IRLU7843.

I could probably increase the AVR-to-gate series resistor to 100 Ohms to further reduce the demands on the AVR's internal FET and still get good gate performance.


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## JimmyM (Jan 4, 2009)

When the FET driver and AVR both habve a 100 Ohm resistor in series, the waves are precicely the same. Stored wave forms for each lay right on top on one another.


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## Mr Happy (Jan 4, 2009)

While I'm following this thread, let me throw in a dumb question:

Is is possible that the voltage spike being attributed to the bulb filament is also partly or mostly from the inductance of the wires from the circuit board to the bulb? And if that happened to be the case, could the spike be reduced by twisting and tying the wires together so that their inductance in each direction canceled itself out? In addition the twisting might introduce a bit of capacitance that would also help to balance out any remaining filament inductance?

Forgive me if this question is too dumb for words, but sometimes it doesn't hurt to ask the crazy questions...


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## JimmyM (Jan 4, 2009)

Mr Happy said:


> While I'm following this thread, let me throw in a dumb question:
> 
> Is is possible that the voltage spike being attributed to the bulb filament is also partly or mostly from the inductance of the wires from the circuit board to the bulb? And if that happened to be the case, could the spike be reduced by twisting and tying the wires together so that their inductance in each direction canceled itself out? In addition the twisting might introduce a bit of capacitance that would also help to balance out any remaining filament inductance?
> 
> Forgive me if this question is too dumb for words, but sometimes it doesn't hurt to ask the crazy questions...


That's not actually a bad thought.
I forst separated the power leads as much as I could.
Then separated them.
Below are the results.
Green = wires separated
Pink = wires together.
White = Shortened wires together.
It's tough to tell the difference between the pink and white. But the white one seems to be the shortest duration kick.


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## Mr Happy (Jan 4, 2009)

Interesting.

Does the flat top of the spike look to you as if it has been clipped? From the shape of it, it almost seems as if it should extend upwards by another two or three divisions to a sharp peak, but has been clipped after a rise of about 40 V as if by a voltage breakdown somewhere?

Is it just my imagination, or is the ringing more prominent in the white trace?

If the spike is caused by inductance, maybe it could be reduced in height by adding a small capacitor in parallel with the bulb? The capacitor might absorb the excess voltage and lower the rise speed at the cost of a bit more ringing afterwards?


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## JimmyM (Jan 4, 2009)

Mr Happy said:


> Interesting.
> 
> Does the flat top of the spike look to you as if it has been clipped? From the shape of it, it almost seems as if it should extend upwards by another two or three divisions to a sharp peak, but has been clipped after a rise of about 40 V as if by a voltage breakdown somewhere?
> 
> ...


Very interesting thought regarding the clipping.
The below scope cap shows the difference between 29.4V, 20.0V, 15V, and 12V input.

Green = 29.4V
Pink = 20.0V
Orange = 15V
Red = 12V





Alan, Will... Thoughts?


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## Mr Happy (Jan 4, 2009)

Wow. That does look like clipping.

I hesitate to suggest something that might blow up your FET, but I wonder what would happen if you connected a capacitor of about 1 uF across the source and drain pins of the transistor? There would be an inrush current when the FET turned on, but when it turned off the cap might absorb the inductive current and reduce the height of the voltage peak? In effect, doing what the Schottky diode somehow was failing to do. The capacitor rating is just a rough guess based on the slope of the dV/dt rise curve on the voltage spike. It might need some experimenting to pick a good value.

Incidentally, regarding the diode, I had a thought about that. When the FET is switched on, the current is flowing in a forward direction. Therefore any diode you place in the circuit has to be reverse biased to the normal current flow, or it will short out. However, when the FET switches off, the inductance in the circuit will try to make the current continue to flow in the same direction. Therefore any diode that was reverse biased before will still be reverse biased. This leads me to think that instead of a Schottky diode, you may want a Zener diode instead? The Zener should have a voltage above the normal operating voltage of the supply, but below the maximum rating of the FET. That way the Zener will break down before the FET does and bypass the current safely.

I'm not sure whether a capacitor alone, a capacitor plus Zener, or a Zener alone would work best in this situation...?

(As before, I'm not an expert in this, so my thoughts should be taken with a measure of due dilligence...)


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## Alan B (Jan 4, 2009)

Mr Happy said:


> Wow. That does look like clipping.
> 
> I hesitate to suggest something that might blow up your FET, but I wonder what would happen if you connected a capacitor of about 1 uF across the source and drain pins of the transistor? There would be an inrush current when the FET turned on, but when it turned off the cap might absorb the inductive current and reduce the height of the voltage peak? In effect, doing what the Schottky diode somehow was failing to do. The capacitor rating is just a rough guess based on the slope of the dV/dt rise curve on the voltage spike. It might need some experimenting to pick a good value.
> 
> ...



First of all, good work, and good comments!

I have not had time to really dig into this, but:

1) The FET inherent avalanche mode is probably doing the clipping. At these low stored energies there may be no danger to the FET, but it would take more research to be sure. The fact that it doesn't fail right away is good but not sufficient.

2) I have had the same thought about the diode polarity, but have not gone carefully through it to be sure. It would seem to be similar to the relay coil driver protection diodes that are commonly used, but the lack of effectiveness makes one wonder.

3) Be very careful about putting capacitance across the bulb. This causes huge current spikes in the FET. The normal way to approach this is to use a snubber, which generally consists of a resistor in series with a capacitor. This will cause the transient to go away faster as energy is absorbed in the R.

4) Using a zener is also possible. If the FET's avalanche specs are not exceeded, there may be no reason to add a part. Further analysis of the FET spec sheets may shed some light on the capacity of the inherent avalanche capability of the device.

5) The inductance of the leads and circuit board are too low. The bulb's coil on coil construction will dominate the inductance of the circuit. I plan to measure that soon, I have an LC meter that is very accurate. Unfortunately it is still in kit form and I need to assemble it...

-- Alan


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## JimmyM (Jan 5, 2009)

Alan B said:


> First of all, good work, and good comments!
> 
> I have not had time to really dig into this, but:
> 
> 1) The FET inherent avalanche mode is probably doing the clipping. At these low stored energies there may be no danger to the FET, but it would take more research to be sure. The fact that it doesn't fail right away is good but not sufficient.


It ran for 3+ hours at 29.4V in, 12VRMS out with a 64625. Ut was warm, but that's it. I'll have to look into avalanche ratings, etc.


Alan B said:


> 2) I have had the same thought about the diode polarity, but have not gone carefully through it to be sure. It would seem to be similar to the relay coil driver protection diodes that are commonly used, but the lack of effectiveness makes one wonder.


I had the diode connected such that current would flow from the FET drain to the Bat+ across the bulb. Otherwize, it would conduct everytime the FET turned on as Mr Happy said.


Alan B said:


> 3) Be very careful about putting capacitance across the bulb. This causes huge current spikes in the FET. The normal way to approach this is to use a snubber, which generally consists of a resistor in series with a capacitor. This will cause the transient to go away faster as energy is absorbed in the R.


Yeah, the capacitor idea just doesn't make sense. It would pull more current from the battery when the fet was on and dump it back through the bulb when it was off. It would increase the RMS voltage to the bulb.


Alan B said:


> 4) Using a zener is also possible. If the FET's avalanche specs are not exceeded, there may be no reason to add a part. Further analysis of the FET spec sheets may shed some light on the capacity of the inherent avalanche capability of the device.


I'll be doing some research regarding this.


Alan B said:


> 5) The inductance of the leads and circuit board are too low. The bulb's coil on coil construction will dominate the inductance of the circuit. I plan to measure that soon, I have an LC meter that is very accurate. Unfortunately it is still in kit form and I need to assemble it...
> 
> -- Alan


Agreed, the bulb's coiled filament is the biggest contributor.


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## JimmyM (Jan 6, 2009)

Below I've calculated the FET amps based on different bulbs and a maximum input voltage.
You can see that even though the bulb itself may not be a super powerful bulb, it can still pull a lot of amps while the FET is on.

Bulb . Bulb DC voltage ..Bulb DC amps .. Supply voltage .. Peak FET Amps
5761 7.2....................5.5.................40.....................30.56
64275 7.2...................6.6.................40....................36.67
64623 15.5.................10.3................40....................26.58
64625 13.2.................9.8..................40....................29.70
64458 20...................10.4.................40....................20.80
1185 11.2..................3.4..................40....................12.14
ROP-HI 7.2.................4.4..................40....................24.44
64430 9.....................7.3..................40....................32.44
62138 13.2.................9.8..................40....................29.70
64655 26...................12.2................40.....................18.77
64657 28 ..................12.3................40.....................17.57

So there may be a limitation on the Vrms to Pack voltage ratio. I'll have to do more testing to make sure. But you can see that running a 64275 on a 40V pack will put a heavy load on the FET.


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## Roland (Jan 7, 2009)

Nice to hear about regulated mag D switches.

Simple option 1) sounds good
The internal circuit is completely dead when off and it will only leak as much current as the MOSFET itself will allow. That's in the area of a few nano or micro amps. However, you're limited to just ON or OFF operation.

Easy v-bulb adjustment for different bulbs is nice and even necessary.

Is a 5761 (7,2 volts) on a supply voltage of 7,3 volts or 8,4 volts also a problem?


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## JimmyM (Jan 7, 2009)

Roland said:


> Nice to hear about regulated mag D switches.
> 
> Simple option 1) sounds good
> The internal circuit is completely dead when off and it will only leak as much current as the MOSFET itself will allow. That's in the area of a few nano or micro amps. However, you're limited to just ON or OFF operation.
> ...


This no problem. Just a turn of the on board pot. I'll have development hardware soon and should be able to start the software development.


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## SafetyBob (Jan 8, 2009)

Jimmy, a raging fire of epic proportions is starting at Paypal awaiting the "send money" button directed to your bank account!!

I cannot wait to slam a couple of these into the flashlights I will have waiting for them.....which reminds me I need to get some more big Emoli batteries. 

As a result there will be strange sightings of flashing lights pointing towards the sky from Oklahoma when you finally send them to me you know.....

Anyhow, glad to see we are all but done except for fine tuning. I just can't say how much I look forward to these being done. The answer to about 90% of our problems solved by one piece of equipment!!

Bob E.


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## LuxLuthor (Jan 8, 2009)

JimmyM said:


> Below I've calculated the FET amps based on different bulbs and a maximum input voltage.
> You can see that even though the bulb itself may not be a super powerful bulb, it can still pull a lot of amps while the FET is on.
> 
> Bulb . Bulb DC voltage ..Bulb DC amps .. Supply voltage .. Peak FET Amps
> ...



Jimmy, that is very interesting, and surprising the Peak FET readings! I totally agree with SafetyBob.


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## Mr Happy (Jan 8, 2009)

Doesn't it seem rather exceptional though, to run a 7.2 V bulb on a 40 V pack? Isn't it more reasonable to match the pack voltage so it is only a few volts more than the target bulb voltage?


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## JimmyM (Jan 8, 2009)

Mr Happy said:


> Doesn't it seem rather exceptional though, to run a 7.2 V bulb on a 40 V pack? Isn't it more reasonable to match the pack voltage so it is only a few volts more than the target bulb voltage?


I think it would be much more common for folks to run a few extra cells for added runtime. A 7.2V bulb on a 12V pack that they can use for anything up to 12V is probably a really common application. Along with things like an 18V pack for the 12V 100W bulbs like 64623, 64625, and 62138.


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## Roland (Jan 8, 2009)

LuxLuthor said:


> Jimmy, that is very interesting, and surprising the Peak FET readings! I totally agree with SafetyBob.



I figured out that the Peak FET readings can be predicted exactly according to:
Peak FET Amps = Bulb DC voltage * Bulb DC amps / Supply voltage


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## JimmyM (Jan 8, 2009)

Roland said:


> I figured out that the Peak FET readings can be predicted exactly according to:
> Peak FET Amps = Bulb DC voltage * Bulb DC amps / Supply voltage


That's right. Straight forward Ohm's Law. Use DC voltage and amps to figure the filament resistance then divide the supply voltage by it. Your equation is the reduced version. Quite straight forward.


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## SafetyBob (Jan 8, 2009)

Mr Happy, you are exactly right.....it is exceptional to run a 12VDC bulb with a 40VDC battery pack. It is runtime we want, and lots of it as long as everything else holds up. 

This will change world order....maybe not with a 623 because you will be able to fry everything (mostly your hand) after say 30 minutes, but think about that wonderful 1185 or 1111 if you like. Super bright, super white bulb with runtime we thougth was only possible with and led flashlight. 

Seriously though, most of the 100watt plus lights are for showing off, that is until you could actually use them practically for 30+ minutes. An hour? 

Let me predict our next problem. How to keep these cool with an integral cooler. Such as 4 big emoli batteries in a 5 D with a tail cap with small slots milled in it to allow cooling air to go through the body pushed by a small 5VDC fan embedded in the tailcap....channels milled in the plastic used to keep the batteries from moving about and finally slots milled in the head to let all that new found heat out. Who needs water proof when it will boil upon contact? 

Can you tell I have been thinking about keeping a high powered [email protected] cool for awhile? I don't know if that good insulation that Lux uses will be good enough to keep the heat away or not. 

Bob E.


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## JimmyM (Jan 10, 2009)

SafetyBob said:


> Let me predict our next problem. How to keep these cool with an integral cooler. Such as 4 big emoli batteries in a 5 D with a tail cap with small slots milled in it to allow cooling air to go through the body pushed by a small 5VDC fan embedded in the tailcap....channels milled in the plastic used to keep the batteries from moving about and finally slots milled in the head to let all that new found heat out. Who needs water proof when it will boil upon contact?
> 
> Can you tell I have been thinking about keeping a high powered [email protected] cool for awhile? I don't know if that good insulation that Lux uses will be good enough to keep the heat away or not.
> 
> Bob E.


The words "evil genius" come to mind. I'd love to be responsible for that type of dilemma.


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## JimmyM (Jan 10, 2009)

The circuit schematic for the JM-PhD-D1 is pretty solid, as is the PCB design. So it's really all down to the software design.
I've made great strides over the last few days. I've been developing with a few Tiny84s I received. I have the ADC reading done along with the PWM.
I want to start reassigning some of pins to make the PCB layout easier, cheaper, AND more noise resistant.
Whoo hoo. FUN stuff. I can't wait to get back to the bench tomorrow.


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## JimmyM (Jan 14, 2009)

Another update:
Software is written and works very well. So far I've only been able to implement 8-bit PWM. The request voltage pots works great. I can set a voltage and ramp the input voltage up and down with no problems. With the full range of 40V, the output voltage is a little "steppy". It has a resolution of 0.15V, so the output voltage will vary by as much as 0.15V during operation.
But it's only visible on a DMM. Bulb brightness is constant.

I'm going to move forward with finishing the board design.
There is only one pot onboard for voltage. If I can find room for a second, I'll incorporate an adjustable low voltage cut-off.

What type of low voltage protocol do you want? Dimming? Pulsing? Shutdown?


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## Alan B (Jan 14, 2009)

JimmyM said:


> Another update:
> Software is written and works very well. So far I've only been able to implement 8-bit PWM. The request voltage pots works great. I can set a voltage and ramp the input voltage up and down with no problems. With the full range of 40V, the output voltage is a little "steppy". It has a resolution of 0.15V, so the output voltage will vary by as much as 0.15V during operation.
> But it's only visible on a DMM. Bulb brightness is constant.
> 
> ...



How about a morse code readout of the voltage? :devil:

Sorry,

-- Alan


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## Roland (Jan 14, 2009)

Eventually there should be a shutdown but not right away. You do not want your light to shut down without a warning. 

Dimming the light to 50% and then in a loop ramping it continually up and down between 15% and 50% would give the best effect. (like the pulsing motion of the glo toob). It would give a clear warning the batteries are almost done and still give usefull light for some time at a low power usage.


I hope the maximum voltage setting itself is going to be finer than 0,15 volt. Because for a philips 5761 (7,0 volt) 0,15 volts more or less is a lot.


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## Mr Happy (Jan 14, 2009)

Roland said:


> I hope the maximum voltage setting itself is going to be finer than 0,15 volt. Because for a philips 5761 (7,0 volt) 0,15 volts more or less is a lot.


You know, the difference in power between 7.15 volts and 7.00 volts at the bulb is 4% at most, more likely 2%. It is likely to be as noticeable as a pimple on a cow's behind. 

I wonder if Philips manages to regulate manufacturing tolerances even half that tightly?


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## Raoul_Duke (Jan 15, 2009)

OMG I cant wait.

It Must have a second Pot to incorporate an adjustable low voltage cut-off.

This Is exactly what Unprotected ~Emoli~ Etc. cells raging at ~11A need to shut them down at ~3V. Its a must have  :kiss: :devil: 

What type of low voltage protocol do you want?  Shutdown !!!!!!!!!!!!!!. 

( Its not like we dont Edc another light for when it runs out, is it :thinking:


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## JimmyM (Jan 15, 2009)

Mr Happy said:


> You know, the difference in power between 7.15 volts and 7.00 volts at the bulb is 4% at most, more likely 2%. It is likely to be as noticeable as a pimple on a cow's behind.
> 
> I wonder if Philips manages to regulate manufacturing tolerances even half that tightly?


That 0.15V is worst case. That will be the resolution when you're running a 40V pack.
Here are approximate resolutions based on battery voltage.
9V = 0.035
12V = 0.047
15V = 0.059
18V = 0.071
24V = 0.094
30V = 0.118
40V = 0.157

So I have a vote for SHUTDOWN!!!!!! an a votes for a low power mode.
I can build it so voltage will sweep up and down from 10% of set voltage to 50% of set voltage upon low voltage kick in.

Alan,
Now you're just showing off you're fancy AVR programming skills 
Maybe not morse code, but rather like the trouble codes on the "check engine" light for a car. 10.8V = 10 flashes ------ 8 flashes. What a pain it would be to count all those flashes.

I did find some really nice 3.9mm cube, multi-turn pots that should be able to fit if I use the smaller voltage regulator that I've found.


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## wquiles (Jan 15, 2009)

JimmyM said:


> Another update:
> Software is written and works very well. So far I've only been able to implement 8-bit PWM. The request voltage pots works great. I can set a voltage and ramp the input voltage up and down with no problems. With the full range of 40V, the output voltage is a little "steppy". It has a resolution of 0.15V, so the output voltage will vary by as much as 0.15V during operation.
> But it's only visible on a DMM. Bulb brightness is constant.
> 
> ...



Great progress Jim 

As to low voltage control/protocol, my 2 cents:
- Above anything, do not shut down without giving the user some warning!
- I prefer some pulsing ON-OFF (like once a second), to let the user know, "hey dude, we are running low on battery!"
- While you are doing the pulsing, let it come out of regulation, which will of course start dimming.
- Once you get to the "hard" low voltage set point, to prevent over-discharge, then and only then shutdown the light. By this point we already have warned the user, so it is fair game to shutdown now to protect the cells.

Again, just my 2 cents 

Will


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## JimmyM (Jan 15, 2009)

wquiles said:


> Great progress Jim
> 
> As to low voltage control/protocol, my 2 cents:
> - Above anything, do not shut down without giving the user some warning!
> ...


I wouldn't let it come out if regulation. There's no telling what battery/bulb combo is in use. Even a nearly depleted 15V pack will pop a 5761.
I could start pulsing between 25% and 85% of the set voltage. Or something like that. Once the voltage drops to 90% of the low voltage set point, I could then shut it off.
For a 3 cell lithium cell pack
Low voltage warning would kick in at 9V(3v/cell) then a hard shut off at 8.1V(2.7v/cell).
For NiMH, low voltage warning would kick in at 1V per cell, then shutdown at 0.9V/cell.
That's the way the 90% figures work out.
That's assuming the user sets the pot to kick in the warning at the right point.
Does that sound OK?
If everyone wants something different with respect to low voltage handling, It will have to be a programming only type of setup. Not pot on the board.


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## Starlight (Jan 15, 2009)

I would like to have an adjustable low voltage setting. I don't care about shutdown protocol.


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## JimmyM (Jan 15, 2009)

I may just have to make a "command decision"...
Adjustable low voltage setting pot.
When activated, light will pulse up and down within a range less than the set voltage. At 90% of the low voltage point, the light will shutdown.

Unless there's a really good reason not to do it this way, I think the above sounds very acceptible.


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## Raoul_Duke (Jan 15, 2009)

JimmyM said:


> I may just have to make a "command decision"...
> Adjustable low voltage setting pot.
> When activated, light will pulse up and down within a range less than the set voltage. At 90% of the low voltage point, the light will shutdown.
> 
> Unless there's a really good reason not to do it this way, I think the above sounds very acceptible.




I think it sounds sweet, I just wanted it to shut down when the cells are too low. 

2.7V may be a bit low for me, as if the cells are out of ballance some could be healthier 2.8v while some may be 2.6V or below;

If it was a choice i'd say shutdown over a warning and up to me to S/D, but if we can both then cool.

But ultimatley if the low shut down can be adjusted I will be happy. :devil:


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## wquiles (Jan 15, 2009)

JimmyM said:


> I wouldn't let it come out if regulation. There's no telling what battery/bulb combo is in use. Even a nearly depleted 15V pack will pop a 5761.


I did not mean to stop regulation if you still had PWM<100%. To clarify, what I meant was that you can continue to operate the light as the batteries deplete, even when PWM is already at 100% (therefore no regulation is taking place), as long as you don't hit the lower safety voltage point for that particular battery/pack. This will work well depending on the pack/cells being used, and of course for some combinations you will hit the low/safe point before the PWM=100%. 

The basic idea is that you keep the light ON as long as you have not hit the low/safe battery discharge set point, even if PWM is already at 100%. This is not my invention, but exactly how the LVR from Willie Hunt worked  

Will


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## SafetyBob (Jan 15, 2009)

Jimmy, my two cents is that initially I was will Will with the on/off blinking thing. I have however, reconsidered it.....a wavering up and down, dim/bright warning would be very effective and will be very acceptable.

It sounds great for a first run.....let's put this baby in the hands of actual people and see what they really think of the interface after using it for awhile. 

So let's get this clearer for everyone. When we order our switch, us dumbies will need to tell you what bulb and what battery setup we will be using so you can set standard voltage that Lux recommends and what lower voltage would be best for our battery setup (emoli, nimh, li-ion, ect). Sound kinda right? 

Actually the above has already been thought of and solved already, but I thought I would bring it up while you were asking about the low voltage warning setup.....

Bob E.


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## JimmyM (Jan 15, 2009)

SafetyBob said:


> Jimmy, my two cents is that initially I was will Will with the on/off blinking thing. I have however, reconsidered it.....a wavering up and down, dim/bright warning would be very effective and will be very acceptable.
> 
> It sounds great for a first run.....let's put this baby in the hands of actual people and see what they really think of the interface after using it for awhile.
> 
> ...


Actually, you would just tell me what voltage you want as the output and what voltage you want the low voltage protocol to kick in.
Bulb is irrelevant, battery pack is irrelevant.
These are completely pot adjustable. You can reset things afterwards if you want.


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## Alan B (Jan 15, 2009)

JimmyM said:


> Actually, you would just tell me what voltage you want as the output and what voltage you want the low voltage protocol to kick in.
> Bulb is irrelevant, battery pack is irrelevant.
> These are completely pot adjustable. You can reset things afterwards if you want.



It might be useful to describe the procedure the user would follow to set the two pots on their regulator.

-- Alan


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## JimmyM (Jan 15, 2009)

I will. I just don't have time for the details just yet.
Setting the low voltage cut out is going to be tricky. But, like setting output voltage, you're going to need a DMM. RMS would be great, but there are procedures for setting with an average reading DMM.
The only other option would be to have the value coded into the regulator.


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## SafetyBob (Jan 15, 2009)

Paypal ready......






And see, I was right, you already knew the answer to my question. I can't wait!!!!!

Bob E.


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## LuxLuthor (Jan 15, 2009)

Jimmy, the variable shutdown would enable NiMH, LiMn/Li-Co, & LiFePO4 which all have their own voltage ranges. AWR's has an abrupt cutout when battery voltage drops below regulation minimum value, and it is quite annoying. So if a warning (of any kind) can be added that would be nice, but not critical. Shame on you if you don't carry at least two lights in a critical application.

I can understand those that want a screwdriver adjustable POT, but for me personally, being able to access the chip, and just compile my own changes is the best option. I'm imagining that putting this under the KIU, will likely limit the access to the chip programming. 

In many cases AWR did the adjustments for a given bulb/battery setup before sending out to people making it a drop-in. I think the final prototype will clear up a lot of questions that people have. Dibs on a bunch of these!


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## Alan B (Jan 15, 2009)

JimmyM said:


> I will. I just don't have time for the details just yet.
> Setting the low voltage cut out is going to be tricky. But, like setting output voltage, you're going to need a DMM. RMS would be great, but there are procedures for setting with an average reading DMM.
> The only other option would be to have the value coded into the regulator.



I know how to set the regulated voltage using a dvm, but setting the battery cutoff is a bit more involved. Perhaps use a variable power supply to simulate the low voltage level and then adjust to that. It would be nice to figure out a way to do it with only the charged batteries and a dvm.

-- Alan


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## JimmyM (Jan 15, 2009)

I have no problem with programming these for folks, but my goal is to make a user adjustable device. It's this low voltage shutdown that's the pain in the a**. Not to implement, just to implemnt in a manner that folks will find acceptible. Alan's regulator is going to be a full on programmable device with a whiz-bang interface. This is supposed to be simple for people to adjust them selves so they don't need a programmer and PC.


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## Alan B (Jan 16, 2009)

*Dual Pot type regulator Adjustment Protocol*

Using an Averaging type DC DVM:

The common DVMs are are fine for this measurement, but they read an average voltage instead of the RMS voltage that determines the heat in the bulb. Some simple calculations will accomodate for this. Note that also some meters that claim to do RMS measurement do not handle it correctly for the PWM waveform. If you have a DVM that is known to measure PWM waveforms accurately in RMS mode you can use that directly and skip the calculations.

Measure battery or power supply that will be used in this test. This source should be higher voltage than the desired bulb and battery cutoff voltages.

Calculate the "low voltage cutoff reading": (formula)

Calculate "bulb voltage reading": (formula)

Remove the bulb and connect DVM to bulb output of regulator.

Connect the power supply or fully charged battery pack to regulator DC input.

Turn the Bulb Voltage pot fully CCW (to zero output voltage).

Adjust Low Voltage pot until meter reads the proper "low voltage cutoff reading"

Adjust the Bulb Voltage pot until meter reads the proper "bulb voltage reading"

Disconnect the power supply or battery, ... (done)

Note that for this to work, the software in the CPU must recognize that when the output voltage pot is set near zero that it instead takes input from the low voltage cutoff pot. As soon as the output voltage pot is set above some small value it returns to normal operation and takes input from there. Alternately, a jumper could be used.

That should work, and it is fairly simple.

-- Alan


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## JimmyM (Jan 16, 2009)

Alan B said:


> *Dual Pot type regulator Adjustment Protocol*
> 
> Using an Averaging type DC DVM:
> 
> ...


Hey, Thanks. These things aren't even built yet and we know how to set them.
Cool.


Alan B said:


> Note that for this to work, the software in the CPU must recognize that when the output voltage pot is set near zero that it instead takes input from the low voltage cutoff pot. As soon as the output voltage pot is set above some small value it returns to normal operation and takes input from there. Alternately, a jumper could be used.
> 
> That should work, and it is fairly simple.
> 
> -- Alan


I was thinking about that today. I was actually thinking about creating an error response if the low voltage cutoff is set too close or above the request voltage.


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## JimmyM (Jan 17, 2009)

I thought I had posted this, but I never hit submit. I got called away from my bench.

Yet another update.
It would appear that I have got 10-bit regulation working.
That means, for a 40V pack, regulation will be about ~0.039V instead of 0.157V.
Also, since the PWM now consists of 1023 steps instead of 255, it's no big deal to program in a nicely adjustable rate softstart. Alan, will tell you an adjustable rate softstart is easy with 255 steps, but he's a better programmer than I am.
So, quite a step. Of course I had a lot of help. Alan helped out a lot with better understanding his 8-bit code, that was really the roadmap I followed to improve things to 10-bit.
So... 10 bit regulation for ALL!


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## Alan B (Jan 17, 2009)

JimmyM said:


> I thought I had posted this, but I never hit submit. I got called away from my bench.
> 
> Yet another update.
> It would appear that I have got 10-bit regulation working.
> ...



Nice progress, Jim.

Making an adjustable rate softstart is mostly deciding how many steps to take per cycle. As long as there are enough steps available it works fine. 255 steps is already enough that it is too slow (for some folks) if you take them one at a time at 250 hz. It could take between a quarter second to a second to come fully on. I don't mind that, but some folks wanted to go faster. So I put in the code a fast start option that takes the milliseconds desired for the start and figures out how large to make each step. It is a somewhat complicated calculation but it can be done in the compiler and so no code is needed in the flashlight for it. It requires knowing the nominal battery voltage. Perhaps the approach in this regulator might be a lookup table so the calculations don't have to be moved into the flashlight. The lookup table could be indexed by the battery cutoff voltage and give the step size for fast starting. Only a few values would be needed. Or just pick a safe fast-start value for the fastest case where Vin is maximum and Vout is low and then for other cases it will be a "nearly fast start". It will vary by a factor of four with Vin/Vout varying from 2:1 to 1:1 as the nominal PWM changes.

Myself, I think the fast-start is not too desirable, after all we are trying to baby the filament here, but of you are going to try to send morse code or generate strobes then fast start is important.

-- Alan


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## Alan B (Jan 17, 2009)

JimmyM said:


> Hey, Thanks. These things aren't even built yet and we know how to set them.
> Cool.
> 
> I was thinking about that today. I was actually thinking about creating an error response if the low voltage cutoff is set too close or above the request voltage.



In order to set the low voltage cutoff pot either a variable supply can be used, or generate a voltage output that tells you were the pot is set. I suspect that most folks do not have variable power supplies, but they do have a DMM. So a trick as I mentioned above, or a jumper to let the CPU know to send the voltage cutoff pot value to the voltage regulation loop so you can measure it with the DMM would do the job.

I like to figure out the user interface before finalizing the hardware design.

-- Alan


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## JimmyM (Jan 17, 2009)

For this design, there is no UI. It's just on and off. I want this design very straight forward, just adjustable for the user. JM-PhD-D2 will have a button interface. Again, something straight forward. Off-(click)-Level 1-(click)-Level 2-(click)-Level 3-(click)-Level 1, etc. Off-press/hold-Level3, from any level Press/hold off.
Since the D1 will not require extensive modding of the existing Mag switch, I want to build that one for the folks now.

I have 1023 steps to go through. So not scaling them during startup gives a slow ramp. So during start-up mode it adda X to the pwmval until it meets the requirement for --pwmval, then it sets the startup flag to 0.

I've got a low voltage warning coded. It quickly ramps the output between 1/2 and 2/3s voltage. Like pulsing. Not flashing. since there is noise in the ADC, it requires 10 successive low readings before the low volt mode latches.
Right now it requires a reset or power cycle to unlatch. I'll be adding a couple of lines to unlatch at 20 or 30 successive readings above.
In this case, if the user sets their low voltage point too low, the light will just turn on in low voltage mode. So there really doesn't need to be a safety.


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## Alan B (Jan 17, 2009)

JimmyM said:


> For this design, there is no UI. It's just on and off. I want this design very straight forward, just adjustable for the user. JM-PhD-D2 will have a button interface. Again, something straight forward. Off-(click)-Level 1-(click)-Level 2-(click)-Level 3-(click)-Level 1, etc. Off-press/hold-Level3, from any level Press/hold off.
> Since the D1 will not require extensive modding of the existing Mag switch, I want to build that one for the folks now.
> 
> I have 1023 steps to go through. So not scaling them during startup gives a slow ramp. So during start-up mode it adda X to the pwmval until it meets the requirement for --pwmval, then it sets the startup flag to 0.
> ...



The potentiometers are user interfaces. 

-- Alan


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## JimmyM (Jan 17, 2009)

Alan B said:


> The potentiometers are user interfaces.
> 
> -- Alan


Ahhh. Gotcha. Yes, I guess they are. I considerd the UI as something the the user manipulated during the use of the flashlight. I just considered the pots as settings.


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## JimmyM (Jan 25, 2009)

An update: I was experimenting with the idea of reading the voltage at the FET drain to compensate for the voltage drop across the FET. But it didn't pan out. So I guess we'll have to "settle" for 0.04V resolution.
I was doing some more testing with the FET I plan on using. It's rated for 40V and can handle a 64447 (65W IRC) in 16.8V RMS on a 37V input. I need to buy a few more bulbs and do some heavy testing right at ~40V. I was also testing it with a 36V input driving a 64275 at 6.8V. That might not sound like much, but the FET was handling ~34A of peak current. No problems.
I've added a few wire pads to the design for future use, so switching to an "always on" design, like Alan is using, is do-able with a simple software upgrade. If you want to change how the board is wired in, or add a new button somewhere for mode selection, etc.

To do...
1) Endurance test with a voltage/bulb combination that is at the top of the range of expected installs. 25V pack driving a 64623 at 15V or something like that.
2) Torture test with 30Vin and 2x64623s at 15V in parallel.
3) Test the expected on-board voltage regulator at full 40V.
4) Get solder paste and a toater oven to practice my reflow soldering. The Tiny84 and voltage reg are leadless SMD parts. 4mm and 3mm square respectively.

I'm going to try to find a deal on a hot air soldering pencil.


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## SafetyBob (Jan 25, 2009)

Sounds great Jimmy. I think it is very realistic that some of us may put a 25VDC battery pack (oh, now I know what to do with those two extra small 12VDC batteries for my UPS) to run one 623 on for an incredible runtime (of course fan cooling goes with it). 

Will look forward to report on the heavy testing. 

Bob E.


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## JimmyM (Jan 25, 2009)

On the "let the smoke out" front.
I was testing at ~35V for a little while when I realized I hadn't yet swapped the the 30V IRLR7843 for the 40V FDD8444!!!!!!!!!!!!! But no smoke. Hmmm. Tough little bugger.
That happened to the first FDD8444 when I bumped the gate lead out of the breadboard and it found a gate voltage somewhere between 0 and 5V generating an enormous amount of heat and just locking somewhere in the not quite ON state as it began to smoke.
Things can go wrong in a hurry with a 64623 on 17Vin. Oh yeah, the bulb went out in the next couple of seconds as I was reaching to shut off the juice.


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## Starlight (Jan 25, 2009)

Jimmy, the top end of the installs isn't a 25V pack driving a 64623 at 15V. I would like to put (8) 18650's in series to run a 64655 at over 26v.


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## JimmyM (Jan 26, 2009)

Starlight said:


> Jimmy, the top end of the installs isn't a 25V pack driving a 64623 at 15V. I would like to put (8) 18650's in series to run a 64655 at over 26v.


Actually, they're both pretty equivalent.
64623 @ 15.5V with 25Vin = 16.61A peak.
64655 @ 26V with 35Vin = 16.42A peak.
It's the peak amps that the FET "feels".
In reality, the 64275 at 7.2V with 35Vin = 32A. So the 35W 64275 on a 36V pack will hit the FET with more current than the 64655.
The watts dissipated will differ.
64275 = ~0.166W
64655 = ~0.566W
Both are a pittance.


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## Starlight (Jan 26, 2009)

I think I understand. The problem in not the level of Vin and Vout, but the difference between the two?


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## JimmyM (Jan 26, 2009)

Starlight said:


> I think I understand. The problem in not the level of Vin and Vout, but the difference between the two?


Yes. Pretty much. I'm sure there is some complex math to quantify it, but basically, you're right.
The 40V FET I'm using now is good up to 50A continuous (with proper heat sinking). But I may have found a better FET, still rated to 40V, but it's good up to 100A and has less resistance. I just need to work out some of the board layout to see if I can fit it. It's larger. But with a previous change in design, I was able to eliminate some of the other components making more room on the board. We'll see. If the smaller one survives torture testing, I'll just stick with the one I've got spec'd.


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## JimmyM (Jan 26, 2009)

I've worked out a board design that incorporates a few differences (possibly improvements)
1) Incorporation of a D2PAK 100A FET
2) 4 future expansions pads for pushbuttons, jumpers, LEDs, etc.
The additional pads will allow the use if this board as the currently proposed ON-OFF only version, but can be used as an "always-on" design like Alan's design which will incorporate a multi-click UI. It can be used as proposed now with current software. But with a future software upgrade and a little re-wiring (very little actually) can be used with the multi-click, multi-level software. This single hardware design can serve both purposes.
With or without the giant FET, the extra pads will remain.

At this point I need to do some experimentation with reflow soldering. I'll try the toaster oven route (plenty of tutorials, how-tos) but ultimately it may require the purchase of a hot air pencil/station. I'm going to explore the option of having the boards professionally assembled, but cost may be prohibitive. I'll have to balance the cost of a hot air pencil against the cost of assembly.


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## SafetyBob (Jan 27, 2009)

Just for kicks, does that mean that this baby is essential ready for us to use with the 1000 watt landing lights then? 

I will get back to reality Jimmy, sounds great, 100 Amp D2PAK is an incredible addition to the board, thank goodness you are the FET expert!!

I wish you luck on the toaster oven thing. I hope it works as well as I have read elsewhere. I am afraid if I did that I would bump something while putting the parts in the oven.....

Boy we are getting close!!!

Bob E.


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## JimmyM (Jan 27, 2009)

SafetyBob said:


> Just for kicks, does that mean that this baby is essential ready for us to use with the 1000 watt landing lights then?
> 
> Bob E.


That would be nice. Wouldn't it. That FET is bad a**, but it doesn't compare to the monsters that I've used in the past.
IRF1324-7 0.8 mOhm. 429A (package limited to 160A), Pulse current = 1640A
IRF2804-7 1.6 mOhm. 320A (package limited to 160A), Pulse current = 1360A
The 2804s get warm during use with the 1000W lights. So a proper 1000W solution will be developed. Same basic design, but it will be able to use the BIG FETs. Several of them if you want.


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## SafetyBob (Jan 27, 2009)

Jimmy, I am wondering if you would see any problems using these electronics to drive one of the Welch Allyn HID ballasts? 

Even though power would be inputted in small, fast tiny pulses (PWM), wouldn't the end result simply be the voltage we want....say 10.4 volts, or is PWM incompatible with ballasts? 

I hope this could work it would again solve alot of extended runtime problems for those lights simply with extra batteries versus figuring out a serial/parallel deal. 

My new battery pack full of big Emoli's should be here towards the end of the week, good for you to have a couple done???

Just kidding. We are really getting close......this is GREAT!!

Bob E.


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## JimmyM (Jan 28, 2009)

SafetyBob said:


> Jimmy, I am wondering if you would see any problems using these electronics to drive one of the Welch Allyn HID ballasts?
> 
> Even though power would be inputted in small, fast tiny pulses (PWM), wouldn't the end result simply be the voltage we want....say 10.4 volts, or is PWM incompatible with ballasts?
> 
> ...


It will likely destroy the ballast. Each time the FET is on, the regulator is putting out the full battery pack voltage. Even in small amounts, it would kill the ballast.
It's going to be some time before I can get these boards built. Alan already has boards made, but I need to get some equipment to actually build the boards. His solution has scads of room to use through hole components, so soldering is a piece of cake. My design HAS to be reflow soldered. Otherwise it will never fit under the KIU.
I have no doubt I'll be ABLE to do it, it's just a matter of purchasing some equipment to actually DO it. Having them professionally assembled could be problematic. I'm trying to keep unit costs as close to $40-$45 as possible.


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## JimmyM (Jan 28, 2009)

JimmyM said:


> That would be nice. Wouldn't it. That FET is bad a**, but it doesn't compare to the monsters that I've used in the past.
> IRF1324-7 0.8 mOhm. 429A (package limited to 160A), Pulse current = 1640A
> IRF2804-7 1.6 mOhm. 320A (package limited to 160A), Pulse current = 1360A
> The 2804s get warm during use with the 1000W lights. So a proper 1000W solution will be developed. Same basic design, but it will be able to use the BIG FETs. Several of them if you want.


I've found my FET for the 1000+ watt crowd. It's a 75V, 240A, 2.1 mOhm BEAST. Of course, they're $7.50 each, but a pair should drive just about anything out there. But that's a project for later.


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## LuxLuthor (Jan 29, 2009)

JimmyM said:


> It's going to be some time before I can get these boards built. Alan already has boards made, but I need to get some equipment to actually build the boards. His solution has scads of room to use through hole components, so soldering is a piece of cake. My design HAS to be reflow soldered. Otherwise it will never fit under the KIU.
> 
> I have no doubt I'll be ABLE to do it, it's just a matter of purchasing some equipment to actually DO it. Having them professionally assembled could be problematic. I'm trying to keep unit costs as close to $40-$45 as possible.



*Sweet!*


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## JimmyM (Jan 29, 2009)

Absent the ability to begin construction of these JM-PhD-D1s, I'm going to begin the feeler for the 1000+W version. I hate to just sit around doing nothing.
I call it the JM-PhD-X1.
The thread is here.
http://candlepowerforums.com/vb/showthread.php?t=221036


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## JimmyM (Jan 30, 2009)

I'm running an endurance test right now.
Input voltage = 40.0V, output voltage ~= 17.0. Bulb = 64447 (65W IRC).
The After 2 hours the FET is barely above room temperature.
Heat has never been an issue, even testing other combinations. But I am testing it at the FULL voltage to see how it responds to repeated avanche current at it rated voltage limit. I'm beyond the input voltage limit of the existing 7805 type 5V regulator, but it seems to be standing up to it thus far. I'm working on getting one of the sample regs I received mounted on a daughrer board for testing.

I have submitted my files for for a quote of fabrication and assembly. We'll see how much this costs. The first batch will be 100 boards.
Do you think the community can use all 100? As before, there will be no pre-pays, I don't like working things that way. If something goes really wrong somehow, I'd rather lose some money rather than my reputation (that's assuming I have a good reputation  ).


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## SafetyBob (Jan 31, 2009)

Testing at rated max.....sounds like you have done your homework well.

I think we will go for 100 boards. I know I could use at least two. I will stick with two to start to allow others an opportunity to purchase this wonderful board. Surely there are 50 of use who could actually use two of these boards. 

Any ideas at all what having the boards manufactured would cost? Any idea at all? Not that I don't want you to have more fun playing in the kitchen with the toaster oven........

Bob E.


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## LumenHound (Jan 31, 2009)

100 would go fairly quickly I would think.


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## JimmyM (Jan 31, 2009)

SafetyBob said:


> Testing at rated max.....sounds like you have done your homework well.
> 
> I think we will go for 100 boards. I know I could use at least two. I will stick with two to start to allow others an opportunity to purchase this wonderful board. Surely there are 50 of use who could actually use two of these boards.
> 
> ...


I ran it until ~10pm last night. No problems, no heat.

I have no idea how much the assembly is going to cost. Really. None. This is my first time getting a quote for something like that. Will is work out to $1/board?, $10, $20? I have no idea.

My wife doesn't have a toaster oven. To do it right, I'd have to get something like the Black & Decker Infrawave. It's a good size oven so I could do several boards at once. But we'll see when that quote comes back.


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## wquiles (Jan 31, 2009)

JimmyM said:


> I ran it until ~10pm last night. No problems, no heat.
> 
> I have no idea how much the assembly is going to cost. Really. None. This is my first time getting a quote for something like that. Will is work out to $1/board?, $10, $20? I have no idea.
> 
> My wife doesn't have a toaster oven. To do it right, I'd have to get something like the Black & Decker Infrawave. It's a good size oven so I could do several boards at once. But we'll see when that quote comes back.



Is this solder reflow the only way for these Tiny84 parts? Do they come in any other package that might be easier to use?

Will


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## JimmyM (Jan 31, 2009)

wquiles said:


> Is this solder reflow the only way for these Tiny84 parts? Do they come in any other package that might be easier to use?
> 
> Will


No. The Tiny 84 comes in 14 pin DIP and SOIC packages as well. It's just that the 20QFN is the tiniest AVR I can find.
QFN20 = 4mm square.
DIP14 = 10.9mm wide x 19 mm long
14SOIC = 3.9mm wide x 8.7 mm long

Maybe I'll see about a 14SOIC PCB layout. Things get pretty snug on that 30mm board with the screw holes, programming header, FET, etc. And there's no way for it to fit in a C-cell body.

Too bad the AVRs don't come in an SOT-23-6 package like a few of the the PICs do. They don't have a PWM section, but I'm told you can do that in software. Our frequencies are very low.
I will be getting some reflow equipment at some point. Maybe not for this first run, But I'll be getting it for expermentation and smaller projects.

The JM-PhD-X1 will use the 14SOIC version since all of the other components will be hand solderable SMDs as well.


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## Alan B (Jan 31, 2009)

A hot air soldering station will do it. You don't have to use an oven.

-- Alan


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## wquiles (Jan 31, 2009)

JimmyM said:


> No. The Tiny 84 comes in 14 pin DIP and SOIC packages as well. It's just that the 20QFN is the tiniest AVR I can find.
> QFN20 = 4mm square.
> DIP14 = 10.9mm wide x 19 mm long
> 14SOIC = 3.9mm wide x 8.7 mm long
> ...



For the PhD-M6, I am basically using a subset of your Tiny 84 circuit design, so there will be no FET driver (and supporting circuitry), so I "should" have enough space to fit the more traditional SOIC package.

Once Eric sends me the prototype pack, I "should" be able to layout around the needed holes. Is your current layout firm enough so that I can start using it for the M6 variant now? If ready enough, I would like to get started 

Will


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## JimmyM (Jan 31, 2009)

Alan B said:


> A hot air soldering station will do it. You don't have to use an oven.
> 
> -- Alan


Yeah. An oven would be nice for doing an entire board, but the hot air pencil should do the trick. I found a Weller WHA900 for about $480. But I'm still searching.

I found this little gem on eBay.
#220351400644


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## Alan B (Jan 31, 2009)

JimmyM said:


> Yeah. An oven would be nice for doing an entire board, but the hot air pencil should do the trick. I found a Weller WHA900 for about $480. But I'm still searching.



MPJA had some under $200, don't know how good they are. 

I have heard good things about the Hakko hot air stations, and I have one of their regular soldering stations that is really excellent for the price. My Weller gets used for antenna connectors and other large stuff, the Hakko gets all the finesse jobs.


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## JimmyM (Jan 31, 2009)

wquiles said:


> For the PhD-M6, I am basically using a subset of your Tiny 84 circuit design, so there will be no FET driver (and supporting circuitry), so I "should" have enough space to fit the more traditional SOIC package.
> 
> Once Eric sends me the prototype pack, I "should" be able to layout around the needed holes. Is your current layout firm enough so that I can start using it for the M6 variant now? If ready enough, I would like to get started
> 
> Will


I'm not using an FET driver on my design either. I'll try to put together a PCB with the SOIC14 and see how it goes. The regulator I have in mind for your design does not require any reflow either. I believe it's a 25V Max Vin SOT-23. AND you don't need the 2 adjustment pots. SO there may very well be enough room. Maybe I'll take a crack at it tonight. I'll let you know how it goes.


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## Mr Happy (Jan 31, 2009)

JimmyM said:


> Yeah. An oven would be nice for doing an entire board, but the hot air pencil should do the trick. I found a Weller WHA900 for about $480. But I'm still searching.


Look here for a hot air rework station at a good price: http://www.sparkfun.com/commerce/product_info.php?products_id=76

Lots of other surface mount soldering tips also at the same site: http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=36


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## JimmyM (Jan 31, 2009)

wquiles said:


> For the PhD-M6, I am basically using a subset of your Tiny 84 circuit design, so there will be no FET driver (and supporting circuitry), so I "should" have enough space to fit the more traditional SOIC package.
> 
> Once Eric sends me the prototype pack, I "should" be able to layout around the needed holes. Is your current layout firm enough so that I can start using it for the M6 variant now? If ready enough, I would like to get started
> 
> Will


On a 30mm board, with no pots, there's plenty of room for the SOIC14.


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## JimmyM (Jan 31, 2009)

Mr Happy said:


> Look here for a hot air rework station at a good price: http://www.sparkfun.com/commerce/product_info.php?products_id=76
> 
> Lots of other surface mount soldering tips also at the same site: http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=36



GREAT tip!. That looks a lot like the Madell and even the tip model numbers are the same.
I searched for that Manufacturer on the web and found an e-tailer that sells the hot air only version (I already have a soldering station). Great prices. I'm a little worried about the prices. They seem too low to get even a modest quality unit. But for $100 (including 4 tips), how can I go wrong? Heck, Weller hot air tips are $60 EACH.


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## wquiles (Jan 31, 2009)

JimmyM said:


> On a 30mm board, with no pots, there's plenty of room for the SOIC14.



That is what I am hoping for, but remember that my "variant" has some sort of surface mount dip switch for the 4 bulb selections - something like this one:
http://www.medibix.com/detail.jsp?view=detail&sku_id=888997&product_id=455722

Will


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## Alan B (Jan 31, 2009)

wquiles said:


> That is what I am hoping for, but remember that my "variant" has some sort of surface mount dip switch for the 4 bulb selections - something like this one:
> 
> http://www.medibix.com/detail.jsp?view=detail&sku_id=888997&product_id=455722
> 
> Will



I'll try removing the duplicate http in your link above. works now.

-- Alan


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## JimmyM (Jan 31, 2009)

wquiles said:


> That is what I am hoping for, but remember that my "variant" has some sort of surface mount dip switch for the 4 bulb selections - something like this one:
> http://http://www.medibix.com/detail.jsp?view=detail&sku_id=888997&product_id=455722
> 
> Will


OK. How many positions long?
Oh, sorry. I see that the spec is for 4 positions. It has a foot print of 6.4 x 7.4mm. It looks like we can come up with something.
Since they'll be inside the light, I'm assuming you just want them read at startup?


----------



## wquiles (Jan 31, 2009)

JimmyM said:


> OK. How many positions long?



Right now I only need two switches, so that I can select between the 4 voltages, but, it would be great to allow for 3 of 4 switches if they fit  . I would also need a programming port, but you probably already have one, right?

Will


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## Alan B (Jan 31, 2009)

JimmyM said:


> OK. How many positions long?



He wants to select one of four bulbs. That only requires two positions. 

How small do they make them?

I have used those type of switches before. It is essentially tiny side by side slide switches. I'm not sure how many cycles they're designed for. It generally requires a stylus or tool to switch them, though a fingernail may work. They may not be designed for a lot of cycles.


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## wquiles (Jan 31, 2009)

Alan B said:


> He wants to select one of four bulbs. That only requires two positions.
> 
> How small do they make them?
> 
> ...



Exactly - thanks Alan (by the way, link fixed - thanks). I am expecting the user will not be changing bulbs daily, for the life of the light, but of course, it needs to be "reasonably" reliable and robust. The link above was just a quick one I found via Google (just to provide an example) - not the exact one I intend to use, as I need to look more into trade-offs of expected life vs. size vs. cost, etc..

Will


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## JimmyM (Jan 31, 2009)

I looked at his link. They have 4 position ones, none smaller by that mfg in that product model. That's OK though. 2 positions to select bulb, 2 other positions to select low voltage point if this is used with extended packs.


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## JimmyM (Jan 31, 2009)

wquiles said:


> Exactly - thanks Alan (by the way, link fixed - thanks). I am expecting the user will not be changing bulbs daily, for the life of the light, but of course, it needs to be "reasonably" reliable and robust. The link above was just a quick one I found via Google (just to provide an example) - not the exact one I intend to use, as I need to look more into trade-offs of expected life vs. size vs. cost, etc..
> 
> Will


At digikey... all washable.
CT2194LPST-ND pretty small ($0.59)
CT2184LPST-ND even smaller ($1.89)
GH7238-ND kinda small ($1.02)


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## wquiles (Jan 31, 2009)

JimmyM said:


> I looked at his link. They have 4 position ones, none smaller by that mfg in that product model. That's OK though. 2 positions to select bulb, 2 other positions to select low voltage point if this is used with extended packs.



That was more or less my thinking - the extra 2 switches would offer a few more options 

Will




JimmyM said:


> At digikey... all washable.
> CT2194LPST-ND pretty small ($0.59)
> CT2184LPST-ND even smaller ($1.89)
> GH7238-ND kinda small ($1.02)



Cool - thanks. Looking at them right now 

Will


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## JimmyM (Jan 31, 2009)

wquiles said:


> That was more or less my thinking - the extra 2 switches would offer a few more options
> 
> Will
> 
> ...


Personally I like the CT2184LPST-ND. It's nice and small. Makes layout easier. However, they cost $1.30 more. That's not a lot if it allows other things in the board. But if it's not needed, then why bother.
That is unless you want to just put one of the half pitch ones in there and use a 6 or 8 position one for some other fancy adjustments.
Positions 1&2: bulb.
Positions 3&4: low voltage point.
Position 5: Low voltage "mode": dim or pulsating
Position 6: Soft-start: fast or slow.


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## wquiles (Jan 31, 2009)

JimmyM said:


> Personally I like the CT2184LPST-ND. It's nice and small. Makes layout easier. However, they cost $1.30 more. That's not a lot if it allows other things in the board. But if it's not needed, then why bother.
> That is unless you want to just put one of the half pitch ones in there and use a 6 or 8 position one for some other fancy adjustments.
> Positions 1&2: bulb.
> Positions 3&4: low voltage point.
> ...



I like those ideas - if we can make it fit, lets go for it :twothumbs

Will


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## JimmyM (Jan 31, 2009)

wquiles said:


> I like those ideas - if we can make it fit, lets go for it :twothumbs
> 
> Will


I'll see if a 6 switch package can fit. It should.
I just got a D2PAK and an FET driver on the board. he he he. Not that I really need it, the DPAK with no driver works fine. I just thought, what the heck.


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## Alan B (Jan 31, 2009)

JimmyM said:


> I'll see if a 6 switch package can fit. It should.
> I just got a D2PAK and an FET driver on the board. he he he. Not that I really need it, the DPAK with no driver works fine. I just thought, what the heck.



With a driver you can run the led at many KHZ. Perhaps use that to make a musical flashlight. :naughty:


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## JimmyM (Jan 31, 2009)

Alan B said:


> With a driver you can run the led at many KHZ. Perhaps use that to make a musical flashlight. :naughty:


If I can work out how to sweep the frequency, I can have it play Green Sleeves when the battery gets low.


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## JimmyM (Jan 31, 2009)

wquiles said:


> I like those ideas - if we can make it fit, lets go for it :twothumbs
> 
> Will


Yup. It fits. Now if I can just get a template of where the holes need to go and what holes are what electrical connections, I should be able to shuffle things about a bit.


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## Bimmerboy (Feb 1, 2009)

Alan B said:


> With a driver you can run the led at many KHZ. Perhaps use that to make a musical flashlight. :naughty:





JimmyM said:


> If I can work out how to sweep the frequency, I can have it play Green Sleeves when the battery gets low.


KILLER IDEA! But who ( or _what_  ) could detect what it's playing?

If some kind of insanity like that could be worked into a low battery warning (using freq, duty cycle, or both if hardware allows), could you transpose the note pitches down low enough to better correspond with visual perception? Many KHz won't cut it, at least not with humans... lol.

I think a seemingly "silly" feature like this would be _un-toppable_ in the flashlight world considering this would be driving an incan instead of LED! 

I have a couple ideas on what might make a pretty cool looking flash sequence based on the "Close Encounters" theme above. Do let me know if I can be of any help.


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## Alan B (Feb 1, 2009)

Bimmerboy said:


> KILLER IDEA! But who ( or _what_  ) could detect what it's playing?
> 
> If some kind of insanity like that could be worked into a low battery warning (using freq, duty cycle, or both if hardware allows), could you transpose the note pitches down low enough to better correspond with visual perception? Many KHz won't cut it, at least not with humans... lol.
> 
> ...



The filament is an inefficient audio transducer, so you can hear something.


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## JimmyM (Feb 4, 2009)

I got a quote for the assembly of the boards.
Eek! JUST the assembly of 100 boards is ~$1500.
To build a bada** relow oven ~$350. To BUY a desktop reflow oven is ~$600. 20 boards relowed in an array = 4 minutes. 5 runs = 20 minutes.
$1500/20min = $4500 / hour.


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## Mr Happy (Feb 4, 2009)

I've got to suppose they want to do 1,000,000 boards rather than 100 boards...? They must be using price to deter small orders, or else they expect to be doing prototypes for businesses with fat wallets...


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## Starlight (Feb 4, 2009)

Jimmy, I know $1500 is a lot of money at one time, but the $15 extra price per board will not deter me from buying them.


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## Raoul_Duke (Feb 5, 2009)

Starlight said:


> $15 extra price per board will not deter me from buying them.



Me Neither...:candle:


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## Bimmerboy (Feb 5, 2009)

Alan B said:


> The filament is an inefficient audio transducer, so you can hear something.



Whoa... I had no idea. That's cool! Bring it on! 

Something like "You Light Up My Life" would be pretty funny. Either that or "Super Freak", which has nothing to do with light, but would crack people up anyway.


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## LuxLuthor (Feb 5, 2009)

Raoul_Duke said:


> Me Neither...:candle:



Nor me with at least 5-8 of them. Plus you have such a reputation that although generally I don't think pre-pay's are a good idea, it would be no problem with you.


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## SafetyBob (Feb 5, 2009)

Ya Jimmy, let us know if you want some money up front. 

I agree, an extra 15 bucks isn't a deal breaker at all......not even close. But you are certainly right, that is a tad bit on the upper end of the scale of what I would have expected....

Bob E.


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## JimmyM (Feb 6, 2009)

Thanks for the votes of confidence, all.
I've just received an unexpected bonus check from work! That's always nice.:naughty:
I was able to appropriate a portion of it from the CFO (wife).
So I've just made a few purchases.
Hot air reflow station
PCB frame
solder paste, syinges, tips, etc
reflow oven building bits 
Some other digikey bits
some tweezers and other bits

Still to get/do:
IR board preheater
remainder of reflow oven bits
Run a few new wires from my breaker panel to my bench to handle the load of all these heating devices. I have enough room for one more 240V breaker. 120/240 20A, 120V 15A

Some will point out that some of this stuff is redundant or unneccessary. But the budget surplus is here now, so I'm getting what I need. Everything.

Next to get are all the boards and components. I'll have the boards made in panels of 4 or 6 boards so I can run them as a batch in the oven.

I'm still undecided about IR or convection. The controller can go either way. I could use a B&D Infrawave (1500W) for IR. But I've read that IR only ovens can scortch plasic components (2 adjustment pots). On the other hand, I could do convection with a Euro-Pro TO289. But it's only 1200W. I've read that these "lower" wattage ovens can't ramp fast enough from 150C to 220C during the reflow portion of the curve. So I think I may have a solution.
I could combine the heaters from 2 TO289 convection ovens and run it on 240V. But to be able to reflow double sided boards you need to be able to heat the top hotter than the bottom and do it quickly. So I can put all of (or most of) the 2nd oven's heaters on the top. So I get the advantage of 2400W of hot air, but with the addition of a bit of IR from the additional elements in the top of the oven.


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## Mr Happy (Feb 6, 2009)

OT, but you are making me envious with all that 240 V talk. I'd love to have a 240 V outlet in my kitchen (electric kettles work much better on 240 V than on 120 V :devil: ). Unfortunately my house is pre-wired behind all the drywall and it is not easy to run new circuits.


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## JimmyM (Feb 7, 2009)

Mr Happy said:


> OT, but you are making me envious with all that 240 V talk. I'd love to have a 240 V outlet in my kitchen (electric kettles work much better on 240 V than on 120 V :devil: ). Unfortunately my house is pre-wired behind all the drywall and it is not easy to run new circuits.



My shop is in my unfinished basement. It's easy to run new wire.


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## JimmyM (Feb 7, 2009)

To be honest, I expected a little more feedback. Well, maybe hoped is a better word. Maybe because I'm so stinking pumped! Do you guys know what this is gonna do for the cost of my designs? The size?


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## Alan B (Feb 7, 2009)

JimmyM said:


> To be honest, I expected a little more feedback. Well, maybe hoped is a better word. Maybe because I'm so stinking pumped! Do you guys know what this is gonna do for the cost of my designs? The size?



Sorry, Jim. We're all jealous. I'm looking at a mill. Restraint.


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## Mr Happy (Feb 7, 2009)

Alan B said:


> Sorry, Jim. We're all jealous. I'm looking at a mill. Restraint.


Jealousy compounded by your having a basement. No basements in California.


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## Starlight (Feb 7, 2009)

We have basements in Florida. They are called swimming pools.


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## JimmyM (Feb 8, 2009)

Alan B said:


> Sorry, Jim. We're all jealous. I'm looking at a mill. Restraint.


A mill is serious business. I read here that the tooling can cost as much as the mill itself.


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## Alan B (Feb 8, 2009)

JimmyM said:


> A mill is serious business. I read here that the tooling can cost as much as the mill itself.



I have a lathe/mill, so have some tooling. One little project required a rotary table/chuck which was itself a project, and cost a good fraction of the lathe/mill. And the very special part I made hasn't been used. yet. But I've used the rotary table/chuck quite a bit on other projects as well.

But, as you know, when you want to do/make something it is worth a lot to be able to.

Incidentally, I recently saw a case where a fellow put a through-hole pad under the center of one of these chips so he could reach through from the bottom and solder the middle pad. Make the hole just larger than a small pencil tip. Interesting thought.


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## LuxLuthor (Feb 8, 2009)

JimmyM said:


> To be honest, I expected a little more feedback. Well, maybe hoped is a better word. Maybe because I'm so stinking pumped!



I for one didn't know enough about those items to be able to appreciate them.  Pray tell?



JimmyM said:


> Do you guys know what this is gonna do for the cost of my designs?



No. 



JimmyM said:


> The size?



No.


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## JimmyM (Feb 8, 2009)

Alan B said:


> Incidentally, I recently saw a case where a fellow put a through-hole pad under the center of one of these chips so he could reach through from the bottom and solder the middle pad. Make the hole just larger than a small pencil tip. Interesting thought.


I had read about doing that. It's good for one-offs, but isn't the "proper" way to do it. I suppose if it works well, it's proper. But hand soldering each of the legs on those 4mm sq Tiny84s would take for ever on a hundred of them. So the reflow approach will definitely aid in production.


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## JimmyM (Feb 8, 2009)

LuxLuthor said:


> I for one didn't know enough about those items to be able to appreciate them.  Pray tell?
> 
> No.
> 
> No.


Oh yeah. Lower cost and and smaller units. I can't wait to get going on the C body regulator. I don't want to get into numbers regarding the cost of the D1 yet, but I think many folks will be very pleased. :naughty:


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## Alan B (Feb 8, 2009)

JimmyM said:


> Oh yeah. Lower cost and and smaller units. I can't wait to get going on the C body regulator. I don't want to get into numbers regarding the cost of the D1 yet, but I think many folks will be very pleased. :naughty:



This design was pretty optimized for low cost, right from the start. However, I would caution everyone not to make the price too low. If it isn't worth your time to make them, it won't last. So make it worth doing, and then everyone benefits from the continued availability and support. Oops. Not yet. Gotta watch that.


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## JimmyM (Feb 8, 2009)

Alan B said:


> This design was pretty optimized for low cost, right from the start. However, I would caution everyone not to make the price too low. If it isn't worth your time to make them, it won't last. So make it worth doing, and then everyone benefits from the continued availability and support. Oops. Not yet. Gotta watch that.


Everyone's a comedian...
In ant case... Good advice. I don't want to have too many orders and not enough time to fill them. But even at a very palatable price point, it will still be worth my time. It will help feed other projects development. Everybody wins.


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## SafetyBob (Feb 8, 2009)

Jimmy, I don't want to make you rich off this project, but I do want you to make enought to make it worth your time.......time to design and make more variations of this project. We already know about the 400, 600, and 1000 watt landing light club that absolutely wants this too. 

Imagine a small nuclear fuel cell making 40 amps of good DC juice. You know how many landing lights we could fit in a POB? Actually, we would put two or three together somehow. They put 3 led's in a [email protected] flashlight here didn't they? 

Actually, I want you to make enought to get the neat toys that makes designing and manufacturing these and other boards fast and easy for you. I want you to be able to go on a little bit nicer vaction this summer and tell the family, this is all due to the generocity of people around the world who just wanted a simple little regulator board in their flashlight to make it more usable. 

What could be better than that? 

Oh, how we coming on those boards too? Yes, another comedian.....

Paypal is still fired up and ready to send. Just give the word.....two for me please (that will be the start by the way.....)

Bob E.


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## JimmyM (Feb 11, 2009)

SafetyBob said:


> Jimmy, I don't want to make you rich off this project, but I do want you to make enought to make it worth your time.......time to design and make more variations of this project. We already know about the 400, 600, and 1000 watt landing light club that absolutely wants this too.
> 
> Imagine a small nuclear fuel cell making 40 amps of good DC juice. You know how many landing lights we could fit in a POB? Actually, we would put two or three together somehow. They put 3 led's in a [email protected] flashlight here didn't they?
> 
> ...


Whoa, I don't know about a better vacation. I don't plan in making THAT much. It will be a comfortable margin. Enough the finance future projects and replenish some money lost on past research on failed projects.
It will help things develop faster and better. It will really improve the production life cycle. I'm really excited about a few upcoming designs.
I've gotten the first of the deliveries today, with others already shipped and on the way.
I'll order the boards and build a prototype using "production" methods. I have enough production style parts for a couple of regulators. Once I've tested them and confirmed proper operation, one or two will go to Lux for testing/proving and the official LuxLuthor stamp of approval.


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## SafetyBob (Feb 12, 2009)

Jimmy, I am excited for you to get some really great equipment, expand your enjoyment of creating actual projects that benefit real people (go with me here I am on a roll)......being able to make better electronic projects over and over again and be able to constantly be able improve your equipment which will certainly improve the results will be a great service to us all. 

So let's see:

D regulated driver
C regulated driver (projected)
small torch driver (<500watts projected)
medium torch driver (1000 watts projected)
larger torch driver (8000 watt or lower projected)

That got them all? I will go up to maybe the 1000 watt landing light, but you KNOW somebody will find an insane bulb that has that 8000 watt level to it......might as well be prepared. 

WAIT......HID? (couple of hundred watts please.....)

But seriously, it sounds like things are coming along very nicely and the results will be beyond what any of us even thought possible......thank you!!

Bob E.


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## JimmyM (Feb 12, 2009)

SafetyBob said:


> So let's see:
> 
> D regulated driver
> C regulated driver (projected)
> ...


D regulated driver - *Check!*
C regulated driver (projected) - *Working on board design*.
small torch driver (<500watts projected) *- Hmmm. Info please.*
medium torch driver (1000 watts projected) *- Schematic in the works. major parts spec'd. Lots of options and a UI to figure out. Maybe an LCD display. 1000W? No problem. 55V? No sweat.*
larger torch driver (8000 watt or lower projected) *- Just add more FETs to the 1000W design up to 55V. After that, let's talk. Bwaaa haaa haaaa* :devil:


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## Mr Happy (Feb 12, 2009)

SafetyBob said:


> larger torch driver (8000 watt or lower projected)


Really? So small?

How about a light built around the 54694 halogen bulb? A soft start for that would be very useful, especially if over driving it.


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## JimmyM (Feb 12, 2009)

Mr Happy said:


> Really? So small?
> 
> How about a light built around the 54694 halogen bulb? A soft start for that would be very useful, especially if over driving it.


Oh, God. What is a 54694? Dare I ask?


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## JimmyM (Feb 12, 2009)

Wait. I just did a search. 20kW/230V. I also did another search and found the FETs that can do it.


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## Mr Happy (Feb 12, 2009)

JimmyM said:


> Wait. I just did a search. 20kW/230V. I also did another search and found the FETs that can do it.


FETs? Really? I kinda wondered if that would be in borderline IGBT territory...


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## Alan B (Feb 12, 2009)

Mr Happy said:


> FETs? Really? I kinda wondered if that would be in borderline IGBT territory...



You folks should come by and visit my workplace sometime. Our newest power supply uses IGBT's to control 2MW. We give tours, but don't usually show off the boring power supplies, but if I give the tour for special guests we might take a different route... This entire machine is built to make light. Sounds like it might be on topic here... Just not this thread... Here:

http://www.als.lbl.gov

But all (or most of) these neat drivers are OT for this thread as I don't think they'll fit in a [email protected] D. Unless it was a mile long. Even then probably not.

Reminds me, I got some neat photo renderings today. Have to post them in the other [email protected] Thread...

Jim, what SMD rework station are you getting? I just got another SMD kit for a ham radio project. I'm going to have to get a rework station soon...


----------



## JimmyM (Feb 13, 2009)

Alan B said:


> You folks should come by and visit my workplace sometime. Our newest power supply uses IGBT's to control 2MW. We give tours, but don't usually show off the boring power supplies, but if I give the tour for special guests we might take a different route... This entire machine is built to make light. Sounds like it might be on topic here... Just not this thread... Here:
> 
> http://www.als.lbl.gov
> 
> ...


I ordered the AOYUE 968 from sra-solder.com Specs are pretty good. I'll probably not use the soldering iron much, but you can connect a vacuum pickup tool to the built in fume extractor. They have another unit, I forget the exact model, but it's ~$50 cheaper. I read a review on it. They didn't speak well of it. Too little power and imprecise air flow control. I'll be getting the Quartz IR preheater as well. The different tips for the hot air handle are quite reasonable. $13 each. They fit Hakko/Madell units as well. The Weller tips are ~$60 each. It's certainly not the same quality as a Weller or Hakko, but I'm not a professional either. If it starts giving me trouble, I can trade up to a different unit. But for $155, how wrong can I go?


----------



## JimmyM (Feb 14, 2009)

I got some stuff during the week while I was away. The soldering station is pretty neat. It came with a few different round nozzles and a square one.
I got the reflow oven controller and parts from Digikey. I'll be getting some more stuff over the course of next week. After that's all set, I'll order boards and parts. Then get crackin'. Whooo hooo I'm getting psyched.


----------



## LuxLuthor (Feb 15, 2009)




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## Raoul_Duke (Feb 15, 2009)

JimmyM said:


> Whooo hooo I'm getting psyched.




You are not the only one....:thumbsup:


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## LumenHound (Feb 22, 2009)

reflow oven...Jimmy..you da Man!


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## JimmyM (Feb 22, 2009)

I picked up an oven this weekend. We'll see how it goes. I also got a couple of other items as well. So I can start some experimentation.


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## SafetyBob (Feb 24, 2009)

How goes the melting? 

Bob E.


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## JimmyM (Feb 24, 2009)

SafetyBob said:


> How goes the melting?
> 
> Bob E.


I'm away on business at the moment. So no melting just yet.
I get home tomorrow night. Then, Thursday night I get to work converting the toaster oven. Remove all semblance of controls, insulate it with ceramic refractory, figure out a controls enclosure (an old UPS should do nicely), wire up the controller, and try to start an empty test run. If all that goes well, I'll test out the pre-heater and hot air system on a couple of SMD breakout boards I have. Once everything is set, this will really shorten my development life cycle. He he he he!!!

Edit: The oven I picked up was at Macy's during their One Day Sale. So It was $29.99. But it's a 1500W convection oven without that stupid hump in the back to fit a pizza. It's top is large enough that if I want to supplement it with a couple of IR elements to top-bias the heat delivery, I have room. Nice.


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## JimmyM (Mar 1, 2009)

Another update to keep those of you following this thread up to date. I finished the build of the reflow oven. Ran it through a profile. The controls work very nicely. However, measurements show that is really only running at 1300W (114V under load), not the 1500W based on 120V. So it can't make time/temperature points recommended by the solder paste mfgs. If you ramp too slowly, the flux activates and dies before the solder melts. Bad for consistency and quality of joints.
So, I've ordered a second oven and will be adding the heaters from that oven to the first. This should deliver 2600W at 220V (228V). I'm running the new circuit from my panel this morning. This is a little setback, but not unforseen. I knew a 1200-1300W oven would be too weak. I don't want to half-a$$ this oven since it will be used for a lot of boards.
So that's the state of things.


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## JimmyM (Mar 1, 2009)

OK. How is it that when I buy a 250' roll of 12/2 romex, the run from the panel to the outlet is such that the "scrap" of 12/2 I have is enough and I don't even have to open the 250' roll. HOWEVER, I buy a 50' roll of 12/3 and the run from the same outlet area is 55' feet away from the panel. How guys? HOW!
Friggin' luck.
Back to Home Depot!


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## SafetyBob (Mar 1, 2009)

Jimmy, welcome to my world......takes at least 15 trips to change a light bulb these days!!

Glad to see you just about have it done though. When you are done you can come here and help snake some Cat5 wire around for a couple of more POE camera's I am installing. 

Shouldn't involve more than a couple of hours of on your stomach in the attic. 

Bob E.


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## JimmyM (Mar 2, 2009)

I've got the 220 circuit in and now I'm just awaiting the arrival of the 2nd oven. It's already shipped. More waiting. If this doesn't do it the way I want, I'll get a B&D Infrawave. This has to be done right. I know there are folks that say, "Oh, you just need a hot-plate", or something else. This oven will be on the money, every-time, no doubt.


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## JimmyM (Mar 7, 2009)

Alright now.
I've got the oven and the controller all working nicely together now.
Below is a graph of the temperature curve I can get using a convection oven. It looks great.









I'll have to make a couple of runs with something in it now to see how it actually works on a real live board.


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## Alan B (Mar 8, 2009)

Is there any cooling control, or only heating??


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## JimmyM (Mar 8, 2009)

Alan B said:


> Is there any cooling control, or only heating??


Right now I just open the door. But it has a control for a cooling fan. I just haven't hooked one up yet.


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## Bimmerboy (Mar 8, 2009)

JimmyM said:


> Alright now.
> I've got the oven and the controller all working nicely together now.
> Below is a graph of the temperature curve I can get using a convection oven. It looks great.



Ha... that is just too freakin' cool. Or rather, in the initimable words of Paris Hilton... "that's hot!"

2600W of DIY reflow power. Nice curve (not that I study reflow curves, but from memory it looks just like the few I've seen), and nice work, Jimmy!


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## JimmyM (Mar 8, 2009)

I made a couple of runs using a couple of SOT-143 FET drivers on SurfBoards. Under close inspection I saw a little Solder Balling (beading). The second run I made I used the tiniest bit of paste. But microscope inspection showed very little solder beading and very nice fillets. I'll be making a couple of small adjustments. A diferent solder paste (higher metal content, 90% vs 87%). I'll also adjust the profile for a shorter soak period. The solder stencil I get will will take care of the amount of paste.
Board design is ready to go.
I'll be ordering boards and parts soon.


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## Alan B (Mar 8, 2009)

Great progress!

Which microscope did you get? I need to look at microscopes. What do you recommend?


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## JimmyM (Mar 8, 2009)

Alan B said:


> Great progress!
> 
> Which microscope did you get? I need to look at microscopes. What do you recommend?


I got mine on eBay. 1.3 MP, 200x. Do a search for USB Microscope. You'll get lots of hits. I use mine in video preview mode. I can see the texture of the solder joints and the surface of a 0603 resistor. You can even see the dot matrix patern of the number code on the top of the resistors. Quite handy.


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## Alan B (Mar 8, 2009)

JimmyM said:


> I got mine on eBay. 1.3 MP, 200x. Do a search for USB Microscope. You'll get lots of hits. I use mine in video preview mode. I can see the texture of the solder joints and the surface of a 0603 resistor. You can even see the dot matrix patern of the number code on the top of the resistors. Quite handy.



OK. We talked about that before. I thought you got a stereo microscope. Glad to hear that is helping out.


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## JimmyM (Mar 9, 2009)

Alan B said:


> OK. We talked about that before. I thought you got a stereo microscope. Glad to hear that is helping out.


Nope. No stereo microscope. I don't need anything that fancy.


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## Alan B (Mar 9, 2009)

JimmyM said:


> Nope. No stereo microscope. I don't need anything that fancy.



I have heard that is the tool for the job. Some are not very expensive.


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## donn_ (Mar 9, 2009)

Surplus Shed has them now and again. Here's a dandy, with camera and all:

http://www.surplusshed.com/pages/item/t1625a.html


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## JimmyM (Mar 9, 2009)

Alan B said:


> I have heard that is the tool for the job. Some are not very expensive.


They ARE the tool for the job. But far too expensive for the benefit over a monocular scope.


donn_ said:


> Surplus Shed has them now and again. Here's a dandy, with camera and all:
> 
> http://www.surplusshed.com/pages/item/t1625a.html



A USED surplus one for $800. Shhesh.


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## donn_ (Mar 9, 2009)

They also have it with a light table, for $1350.


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## Alan B (Mar 9, 2009)

My apologies if this is getting too far OT. I'll let the OP let us know if he feels that way.

The microscope my friend bought was under $300 on eBay. He is setting up for SMT work. The scope has 10x, 30x, boom, fluorescent ringlight, 4" working distance, etc. It seems to be inexpensive but serviceable. For a few dollars more they have the trinocular version that will take a camera. You can attach a medium resolution USB camera or a higher resolution still camera for photos and videos. These won't go to 200x, but some do go to 90x. For PCB work I don't think the high magnification is required though perhaps there are occasions where it is needed. Generally 10x or so is adequate for inspection and rework, is it not?

I was wondering, it is fine for inspection, but how does a video microscope work for re-work? Does it have the working distance to get the tools in? How does the brain handle looking at the screen and coordinating hand motions?

Search eBay for ...binocular 10x 30x stereo boom microscope ring light... to find a few different ones.

Perhaps someone with microscope experience would comment on how these inexpensive units differ from the big boys. A lot of our flashlights are made on similarly inexpensive lathes and mills, they seem to get the job done, especially for those of us who use them part time.


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## Mr Happy (Mar 9, 2009)

Well, my poor old eyes are no way up to the task of seeing the small detail required to manipulate and solder SMT components, so some kind of vision assistance is essential.

As an experiment I bought one of these from Harbor Freight tools: http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=95890

It is basically a binocular microscope you wear on your head. It works fine for manipulation and soldering, and the relatively low magnification is all you need. The difficulty is keeping your head still enough and correctly positioned so the work remains in focus, and the trouble seeing other things when you move your eyes off the work and everything becomes a blur. The flip-up feature on the visor is essential for this.

So the advantage of a binocular microscope would be a stable work and viewing platform to keep everything in focus, and being able to see normally when you take your eyes away.

I don't think you need more than 5-10x magnification, and I don't think you need superb optical quality. So the question is, are there any options out there at a more reasonable price between my $9.99 visor and a $300+ lab instrument?


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## JimmyM (Mar 21, 2009)

I'll let this go. It's just a feeler thread.
But I don't need any real magnification for component placement. I've been soldering 0603s, SC-70s, etc without magnification. I use magnification from my USB microscope for inspection afterwards. Also, exact component placement isn't actually necessary when reflowing. The surface tension of the molten solder will self-postion the component. Probably the most critical one is the QFN20 Tiny84 itself, but I have alignement marks on the board to help that.
I've ordered some different paste and sent the design out for quote.
Getting close.
Oh. In case I didn't mention it before... The oven is FANTASTIC.


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## SafetyBob (Mar 21, 2009)

That's great news Jimmy......you know all my projects have come to a halt waiting for your driver!!

No pressure though!!!!

Seriously though, I have alot of machine work to do to put charging jacks and all that crap in the lights let alone the shortening thing to correctly make those bid emolis fit superbly.

No hurry, keep pluggin' along....

Bob E.


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## JimmyM (Mar 22, 2009)

SafetyBob said:


> That's great news Jimmy......you know all my projects have come to a halt waiting for your driver!!
> 
> No pressure though!!!!
> 
> ...


Trust me. I'm DYING to get these built. First couple go to Lux for an objective 3rd party flogging. Then the sales thread opens.


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## JimmyM (Mar 29, 2009)

This thread had gotten a little long. So I started a Part 2 over here.

Could the admins please close this thread.
Thanks.


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## SilverFox (Mar 29, 2009)

JimmyM has started part 2 here. I will close this thread and the discussion can continue over there.

Tom


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