# How far can I push it?



## donn_ (Dec 5, 2008)

I can get 5x 26650 A123 cells into my 6D 64623 light. Those cells will measure between 16.5V and 17V.

In Lux's Destructo Charts, this bulb flashed at 16.9V.

There are no resistance fixes in this light, and it's running one of AW's soft-starters. There's also a 1.5" copper spacer to fill up the tube.

Will it flash, or will it work?

:devil:


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## modamag (Dec 5, 2008)

donn, you'll be OK with 5x.

Fresh off the charger these should be 3.65V / cell.
But once you put any load (1C) on the A123 they drop to < 3.3V/cell.
You're gonna be pull mucho 4C on that baby during the run and alot more when it's cold start.

sOT: One thing to keep in mind is to terminate charge @ 3.65V I had a few that failed inside the Dewalt pack due to inballance and were charged to > 4V of their charger. These were revived but loss somewhere btw 10-20% capacity & suffer the worst during heavy draw.

My application is 30-40A of a 4P pack.


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## donn_ (Dec 5, 2008)

Thanks, mate.

Maybe I should just move up to the 64633. They don't cost much more, and I'll get more lumens and bulb life.

That looks like as far as I can go, and still use the AW soft-starter.



> You're gonna be pull mucho 4C



That C stuff is way over my head. I'm using these cells because of the quick recharge, and their supposed ability to handle heavy draw.


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## mudman cj (Dec 5, 2008)

I don't think you would go wrong with either one, but they do have some interesting advantages and disadvantages as I see it.

Advantages of 64623:
-Whiter color temp
-Higher efficiency in the visible spectrum
-9.4% longer runtime from Luxluthor's measured currents
-Shorter filament for better focusing


Advantages of 64633:
-7.2% more predicted lumens output from Luxluthor's lux measurements (assumes 16.25V pack voltage)
-In excess of 7.2% more infrared output for starting fires :devil: because of the combined effects of increasing power output and shifting the spectrum further into the infrared (lower color temperature).
-Longer bulb life

IMO, this is probably a show off light primarily due to the short runtime, and therefore more lumens means a bigger smile.  And who wants to say, "No, really. It does start fires. Yeah, sure. Let me get some newspaper..." only to have to wait through agonizing seconds of torture wondering exactly when it's going to burst into flames. :sweat: But I wonder how much quicker the 64633 would start a fire or from how much further away it could be done. The differences may not amount to much or matter to some.


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## LuxLuthor (Dec 5, 2008)

You have at least 300 mOhms of resistance (220 from AW's D Driver alone), so if you are running a bulb like 64623 which uses a ballpark of 10Amps, that will drop 3 volts (10A x 0.3 Ohms). You still have a startup current spike with a cold bulb filament which is what instaflashes most bulbs, but you should be far enough from the edge to not have a problem.

Problem with trying to go up to the 64633 150W Osram is that it needs more voltage than 16.5V (5 x 3.3V A123's) will deliver (especially subtracting the resistance voltage drop), and it will just look crappy being underdriven.


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## donn_ (Dec 6, 2008)

> ...it will just look crappy being underdriven.


Well...maybe not overdriven as hard, as opposed to underdriven.

I'm currently running the 623 on 4x A123s, and while it isn't pushing the lamp as far as it can be pushed, it looks pretty good.

At 16.5V, the 633 provides 7067L for 15.9 hours. The 623 provides 6589L for 16 hours. There's probably a little less chance of flashing the 633, no?

Another question...the cold filament issue. Does the AW soft-starter adequately warm the filament, or does it flash at even the lowest level?

As for fire-starting, I have one of these:







:devil:


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## mudman cj (Dec 6, 2008)

That is a nice firestarter donn_! :laughing:

Luxluthor makes a good point. My estimates of difference in light output and runtime difference are off because I didn't account for voltage drop in the rest of the circuit (everything except the bulb filament). So the 64633 will only be driven at 13.25V give or take and will be quite yellow. With 300mOhm resistance dropping 3V in the light, you would get a nicer result with a 6th cell for around 19.5V, but I know that's probably not a good option. So, I have to agree with Lux that the 64623 is going to look better, especially since you seem more interested in the light than the heat.


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## modamag (Dec 6, 2008)

Regarding soft starting, only 100ms is require to ramp up the filament. I think AW's driver is running like 1000ms or so. All SS does is slowly let the current in.

The low/med/high is just the duty cycle (how fast you turn it on-off-on). It should not make a significant difference between these modes.

IMHO, the voltage sag under load is the more important factor. With SS you're not shocking the filament but with enough voltage you'll still pop the bulb.

If you're brave enough try out the molicell from Milwaukee V28 pack. With 5x of those cells & the 623 you'll get one heck of a light.

Here's the theory.
5x Molicell 26600 are 3Ah so you'll be pulling like 3.4C effectively 3.8V/cell max.

So 3.8V * 5 cells - 3V switch resistance will give you 16V.
[size=+2]This should put out twice as much lumens compared to the M1 cell setup[/size]


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## donn_ (Dec 6, 2008)

I just measured a string of 5 of the Emoli cells, and got slightly over 20V. They haven't been charged recently, but measured 3.97 to 4.1 each.

They haven't been shrinkwrapped yet, but I've been using them in D-Mags with a 1" poly irrigation tube sleeve.

The problem is they take so much longer to charge than the A123s. I really need to upgrade my charging hardware.


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## modamag (Dec 6, 2008)

Hot off the charger they're 4.2V.
Sitting for a while they'll drop 0.1-0.2V

However the magic occur while under load i'll just be 3.5-3.6V.


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## donn_ (Dec 6, 2008)

<GRIN>

I was reading your thread on the Colossus Vaporizer, when the email alert to your reply popped in.

Sounds like a real beast of a light!


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## LuxLuthor (Dec 7, 2008)

donn_ said:


> Well...maybe not overdriven as hard, as opposed to underdriven.
> 
> I'm currently running the 623 on 4x A123s, and while it isn't pushing the lamp as far as it can be pushed, it looks pretty good.
> 
> ...



When I said the 64633 being underdriven, I was taking the ballpark resistance of your setup, and the voltage of cells under load into account. 

Your Lumen & Bulb Life estimates are taken from my destructive testing chart, but if you are measuring 16-17V without load, then under load resistances of AT LEAST 300 mOhms x 11.5 Amps, you must subtract 3.3Volts, putting you below the default manufacturer's rating, and underdriving it.

In contrast, anything over 12V is overdriving the 64623 bulb from default ratings...but it is almost certain that 4 x A123 cells is also underdriving that bulb. Those cells drop to 3.3V almost immediately under load, so you are starting with only 13.2V, then again must subtract 3 Volts from resistance losses.

AW's driver indeed has the effective soft starting effect of blocking the sudden inrush current into a cold filament.

My graphs of the LiMn vs. A123 show the voltage range differences under loads. These are 18650 size cells, but the 26700 size of A123 vs. Emoli in terms of voltage under load will parallel these charts. The higher voltage of LiMn is one of the reasons (in addition to more common charger algorhythm, and availability, etc) some of us prefer these cells. Obviously the RC crowd wants maximum amp output, so for them the A123 is preferred.


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## donn_ (Dec 7, 2008)

I think I'm making progress, both in understanding the science and testing it out.

I put the 5th cell behind the 623, and the result is outstanding.

Now I'm thinking about a 6th cell. I have sufficient extensions to go to 7 or 8 cells. Tell me if my reasoning is accurate:

6xA123 is 19.8V before resistance loss. Figuring at least 3V lost to switch and other resistance, _*plus additional loss due to the added joint in the tube*_, still keeps me below the 16.9V flash point of the lamp.

Right?

Using the 633 instead, with 6xA123 gets me about a thousand more lumens, a few more degrees of heat and about 30% shorter bulb life.

Right?

Of course, I may need a sling to carry what will essentially be a 7D Mag with a 3" head.


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## modamag (Dec 7, 2008)

IMHO, worth a $4 try
If I was a betting man, I'll give you 30% of sucess from fresh cell.

If you have the equipment, drain 20% from your cell first before trying.

Geesh, Mag7D with 3" head and 6x A123, that thing must be like 8 lbs. You'll get your excercise for the day by wielding it :nana:


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## donn_ (Dec 7, 2008)

The problem is I only have 1 lamp right now. I'm placing an order today for more, both 623s and 633s, and possible some others. Once they arrive, my bravery will increase.

When will you have some black Colossus heads?


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## mudman cj (Dec 7, 2008)

donn_ said:


> I think I'm making progress, both in understanding the science and testing it out.
> 
> I put the 5th cell behind the 623, and the result is outstanding.
> 
> ...



I think it has a better chance of working than not. As Lux said, you will lose over 3 volts from the 19.8V pack voltage under load. There would be no way without the soft start, but with it you should have the same situation as Lux did when he slowly ramped up the bench top power supply.


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## LuxLuthor (Dec 7, 2008)

Donn, the only concern I have is the starting voltage of fully charged A123 cells starts at 3.5V before it quickly drops to a more stable 3.3V, so I'm not sure when you push up to the flash limit of my destructive tests if the AW soft starting delay will cover that brief initial higher cell voltage. When you push to the edge, anticipate a bulb failure and/or reduced life.

I never completed the bulb life part of my destructive tests, so those life estimates are not reliable.

I'm not *exactly *sure how much your total resistance is. I'm starting with AW saying his driver was 220mOhms. I have verified that tailcap spring resistance is 60mOhms, and every contact point will have some increase in total resistance.


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## TKO (Dec 8, 2008)

LuxLuthor said:


> Problem with trying to go up to the 64633 150W Osram is that it needs more voltage than 16.5V (5 x 3.3V A123's) will deliver (especially subtracting the resistance voltage drop), and it will just look crappy being underdriven.


 
Lux,

I have to beg to differ. My Sleeper mod is quite white on high, but then I do have a low resistance tail cap mod.

Best Regards,

Rick


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## LuxLuthor (Dec 8, 2008)

TKO said:


> Lux,
> 
> I have to beg to differ. My Sleeper mod is quite white on high, but then I do have a low resistance tail cap mod.
> 
> ...



Rick, it may be brighter than many lights you have seen, but 5 x 3.3V = 16.5V @ 11.3Amps. With 220mOhms in AW D driver, and at least 30mOhms for other resistance, you are losing almost 3 volts (.25 Ohms x 11.3A = 2.83V). 

The default spec of the bulb is 15V @ 10A giving 5600 bulb lumens. However nice it looks to you, it is being underdriven at less than 14 Volts. Put 5 Emoli 26700's in it, or a 6th A123, and you'll see what it should look like. With various 2000+ lumen output bulbs, quite honestly they all look white and bright to our eyes, so I'm not questioning what you see.

If you like it the way it is now then by all means, enjoy it. My point is to underscore that this issue of resistance losses is real, and has an effect on the bulb output and color. Most of these bulbs are not meant to be underdriven vis-a-vis light color and lumen output.


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## donn_ (Dec 9, 2008)

LuxLuthor said:


> ..5 x 3.3V = 16.5V @ 11.3Amps. With 220mOhms in AW D driver, and at least 30mOhms for other resistance, you are losing almost 3 volts (.25 Ohms x 11.3A = 2.83V).



I'm really confused about this calculation of voltage lost to resistance.

Your formula is applying the resistance (.25Ohms) to the Amp draw with the un-resisted voltage (16.5V).

Where is the amperage? At the bulb? If so, wouldn't you use the Amp draw of the resistance reduced voltage?

I'm putting together a 3D Mag with an AWR HD set at 11.1V and running 3x Emoli cells. Which bulb is better, 1164 or 1185?

Sorry to be such an idiot about this, but I'm trying to learn how to figure it out myself. I have enough of these two flavors of bulb to afford to blow a couple, but I'd like to be able to make an educated guess.


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## modamag (Dec 9, 2008)

donn, the current is what being drawn. Since your switch and bulb are in series with the battery it's the same current.

Let take for example your Mag3D
1) 3x MoliCel 26600 with a ~4A will have an average underload voltage of 3.7V per cell.

2) Now with AWR HD (not AW 3-level) will have about 500mOhms resistance. These varries from each unit depending how he felt that day.

3) So with Ohms law V = I * R 
To find the voltage drop through the switch & spring is 0.500 * 4A = 2V.

4) Next you to find the voltage at the bulb.
Vbat = Vswh + Vbulb
Vbulb = (3*3.7V) - 2V = 9.1V

4b) Now use that voltage value go to Lux chart and find the corrent current draw and reiterate step 1-4 one more time to a more accurate Vswitch and Vbulb value.

5) With Lux's awsome chart you can guestimate that :
- the 1164 @ 9.1V yield 1200 bulb lumens
- the 1185 at similar voltage is underdriven and would get < 800 lumens.

Now let's analyse the results.

If you use AW's 3-stage switch you'll get 250mOhms resistance instead of 500mOhms which increase your drive voltage by 1.0V which would significantly increase your 1164 bulb lumen to 1600. Not too shabby.

If you're doing like many have done driving with 18650 instead of the beefy 26600. The average voltage is alittle worse @ 3.6V
and you'll loose about 200 lumens with the 1164.

The bottom line is with 3x MoliCel you will not blow anything and get better theoretical results with 1164.

I hope this is clear.

BTW: I'm 3/4 finish with your toy. It's amazing what couple hours of peace and quiet can do. I'll post it soon


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## donn_ (Dec 9, 2008)

I guess I'm officially an incan man now...I just flashed a bulb!:sick2:

I plugged an 1164 into the light with the AWR HD and it popped.

Back to the drawing board. The string of Emoli cells measured 11.88V.

It runs an 1185 with no problem. Real nice beam, too, in one of FM's old 2" throwmasters.


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## donn_ (Dec 9, 2008)

Two down!

I tried the 1164 on 3x Emoli cells, through an AW switch. I gave it 10 seconds on low..no problem. 10 seconds on medium..no problem. Switched to high and 

I guess I'm stuck with under driving the 1164 on 3xA123s.

Unless...and this is something I'm not sure about. The AWR LDO HD is set at 11.1V. Does that mean it's regulating 11.1V to the bulb? If so, and if my string of cells reads 11.8, it must be boosting the voltage, right? Because the resistance is knocking down the battery voltage.

I've read the AWR HD setting can be adjusted, but I can't find out exactly how. There seems to be a lot of missing threads on AWR topics. There are two tiny recessed phillips head screws in the top of the HD heatsink.

Any idea of how this adjustment works?

If I lower the setting to 10.6V will I keep the 1164s from flashing?

I could probably stick a couple of pieces of fine wire into the bi-pin socket, and rig up my DMM to measure the voltage, couldn't I?


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## LuxLuthor (Dec 9, 2008)

This topic is getting more confusing now when mixing AWR & AW drivers.

Although member AWR is not related to AW, the confusion is related to similar letters, and that both made a bulb holding Mag D Driver. I'm not sure what modamag was referring to when he said that AWR's Hotdriver had 500mOhms, but that is not accurate as far as I know. There was a "High Current" variation of the AWR Hotdriver that would add some resistance with the use of a 25AWG wire, but this will get too complex for this thread.

Indeed AWR (Andrew Wynn Rouse) who lives in Wisconsin, USA (AW lives in Hong Kong) made an adjustable Hotdriver, but unfortunately the image links from that thread have been deleted. Luckily, I saved a copy of all his posts offline. This image shows the two adjustment fine/gross "pots" (at top) with phillips screwdriver through the 2 holes of KIU base you mentioned. They are marked as "R0" & "R1" at top of image, and to the left of "C4."







Easiest way to set the delivered bulb voltage is to insert batteries in light. Turn off power switch. Put two stiff copper wires (like from home Romex wire, or even a segment of a paperclip) into the KIU bipin bulb holder holes. Then turn on light and touch DMM leads to the wires to see the bulb voltage.

Turn off switch. Make adjustment of fine/coarse POT screws, turn back on take new reading, etc. etc. until you get it where you want. I won't get into issues of AWR hotdriver with 100W+ bulbs, nor the standard and high current variations.

My destructive charts list the ACTUAL, measured current (Amps) of what the bulbs used at various voltages. Otherwise how to measure amps is another discussion.

You should NEVER just put a bulb into a AWR Hotdriver and assume it is delivering the correct voltage for a given bulb unless you measured it with above technique. You can use my charts to pick the optimal voltage for a given bulb. If it says 11.1V written with Sharpie, you must supply higher than that with batteries, and it will be regulated down to 11.1V. The AWR is not a boosting driver, so if you have a net delivered voltage that is too far below set voltage the driver shuts off. You can read about it and the current setting in his thread. I'm not sure which model you have, and there are a number of setups and models that AWR put out.

Now completely separate from the AWR Hotdriver which has soft starter, and lets you adjust the delivered bulb voltage...is the AW Driver which only has a soft start. It delivers the voltage your batteries have, otherwise known as "Direct Drive" (AKA: Unregulated Driver). With AW's setup, you must get your battery voltage correct (taking into account resistance losses).

I would recommend you set the AWR Hotdriver to 9.5V for an 1164

When I use it for my 1166, I set it at 12.7V

This other topic may be of use as background.

_*Interesting sideline: Many of the original AWR images and links were at this URL http://rouse.com/hotdriver However, apparently http://rouse.com has been sold to an international company who is now using it.*_


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## donn_ (Dec 9, 2008)

Thanks, Lux.

Do you know which screw is coarse adjustment, and which is fine?

Why do you recommend 9.5V instead of the highest non-flashing level of 10.6V? Bulb life?

I knew the difference between AWR and AW. I've read a lot about AWR's ill-fated projects, and even have one of the M6 body extensions. Somehow, I missed finding the thread you linked.

Thanks again.


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## LuxLuthor (Dec 9, 2008)

donn_ said:


> Thanks, Lux.
> 
> Do you know which screw is coarse adjustment, and which is fine?
> 
> ...



I have copies of a number of AWR's threads that seem to have been deleted now...or may be intentionally (understandably) obscured. 

The 10.6V may mean that the bulb will last a minute, or several minutes, or several hours. It also does not take into account the sometimes radical decrease in lumens after short run times at higher overdrive voltages.

Part 2 of my destructive testing was to see what was the ACTUAL bulb life at a given voltage before it burned out, vs. what was predicted from extrapolation at Welch Allyn's bulb URL info. I discussed this in post #17 above.

Suffice it to say that there is increasingly less correlation between the predicted bulb life in my charts (or AWR's Hotrater spreadsheet) and actual bulb life and lumen output as bulb overdrive increases (see link in #17).

I'm pretty sure (from memory) the screw closer to the C4 is coarse....but you should play around with them to make sure.


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## donn_ (Dec 9, 2008)

Argh!

I think this HD is going to try my patience.

I set it up as you described, using the pins from a blown bulb...and got a reading of 10.8V on the DMM.

I turned the screw furthest from the C4, about a half-turn clockwise, just to note what happened.

I tried to get another reading, and nothing registered on the DMM.

I turned the same screw back, still no reading.

I tried longer pieces of fine paper clip wire, still no reading.

I tried twisted copper wire, still no reading.

I tried an 1185, it lit just fine.

I checked the DMM on another cell, all was well.

What am I missing?


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## cnjl3 (Dec 9, 2008)

Donn, 
One of my AWR hotdriver's is weird in that I can only measure voltage adjustments with this method. Make your adjustment and if you cant get a DMM reading-switch the HD off--then turn it back on again and then you will see the adjustment in your DMM It sure makes for a longer session but at least I am able to adjust the HD. I dont know why - but this method works with one of my AWR HD's. The other AWR HD adjusts normally without having to turn it on and off with the MAG switch between adjustments. Hope this helps. 
My 1164 w/AWR's HD set at 9.6V kicks butt!
My 1185 w/AWR's HD set at 11.1V seems brighter to me.


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## LuxLuthor (Dec 9, 2008)

Sounds like CNJ has run into this. I have not. I have 12-14 AWR Hotdrivers, and they can all be tweaked with the method I described. If I talk to AWR again, I'll ask him about this.


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## donn_ (Dec 10, 2008)

I'll try it CNJ's way, after a little more coffee.

Do you suppose it's the low-voltage cutoff?


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## donn_ (Dec 10, 2008)

I think I've gotten it done...you experts let me know before I  another 1164.

On the theory the HD's low-voltage cutoff was standing in the way of getting a reading, I rigged up a little harness to temporarily hold an 1185, and plugged the other ends into the sockets of the HD, leaving enough exposed wire to use the DMM:






This kept the bulb far enough away to avoid blinding myself. I actually set up a piece of showcard to further shield the lighted bulb.

It worked...I got an 11.1V reading, which is the setting written on the HD.

After a few cycles of turning the impossibly tiny screws, I ended up with a 9.54V setting, about halfway between Lux's and CNJ's recommendations.

Am I safe to now try another 1164?

With a 92% low voltage cutoff, I'll be at a hair over 2.9V per cell. That's pretty low, isn't it?


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## donn_ (Dec 10, 2008)

Thoroughly embarrassed by the Rube Goldberg nature of my rigging in the above photo , I went into my parts boxes and foraged these parts.






Shamelessly stolen from Lux's setup , this arrangement should serve me much better. 

Back to the questioning:

If I take a Mag tube with AW's softstart multi-level switch and a string of cells, stick a couple of steel pins into the bi-pin socket, click the switch 3 times and measure the voltage at the steel pins, do I have an accurate measure of the after-resistance voltage going to the bulb?


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## LuxLuthor (Dec 10, 2008)

That voltage setting should be no problem for 1164. I'm still puzzled why you can't check it with just the wires in the bulb socket holes, as long as you have good battery contact...unless your cells had voltage less than 8% of where it had been set.

That voltage won't hurt the A123's. They are damn near invulnerable. You will notice the sharp drop off in their performance (shown in testing charts), then they will rebound back up a bit. Just don't keep hitting them once you get the first low voltage shutoff by hotdriver.

I'll warn you though, once you learn how to set the HD, and see the consistent regulated output, it is very hard to go back to direct drive. It's why I'm so supportive and interested in AlanB's project which takes this to another level.


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## LuxLuthor (Dec 10, 2008)

donn_ said:


> Thoroughly embarrassed by the Rube Goldberg nature of my rigging in the above photo , I went into my parts boxes and foraged these parts.
> 
> Shamelessly stolen from Lux's setup , this arrangement should serve me much better.
> 
> ...



Nice plank of wood! :laughing:

I'm not sure what you are doing with this vis-a-vis AW's switch? You are jumping between AWR, AW, and a bulb holder in wood for me to know what you are asking about. There should be no reason you have to put the wires from the wood bulb holder into the AW switch.

If you are asking a completely unrelated question from the wood plank holder, then the answer is no because you don't have a completed circuit with bulb resistance & current flowing to measure resistance.


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## donn_ (Dec 10, 2008)

LuxLuthor said:


> I'll warn you though, once you learn how to set the HD, and see the consistent regulated output, it is very hard to go back to direct drive. It's why I'm so supportive and interested in AlanB's project which takes this to another level.



Ha! I've been watching that, AW's threatened M6 soft-start 3-level switch, and his semi-threatened regulated switch. AlanB's thread is so far over my head it's ridiculous. How in the world will y'all get that 8" square circuit board Will's playing with into a flashlight?!?

I hope to see a couple more of AWR's HD hit the aftermarket, but it sounds like you have most of them. The one I have came from Litho, almost a year ago, and I haven't seen another one for sale since.


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## donn_ (Dec 10, 2008)

LuxLuthor said:


> Nice plank of wood! :laughing:
> 
> I'm not sure what you are doing with this vis-a-vis AW's switch? You are jumping between AWR, AW, and a bulb holder in wood for me to know what you are asking about. There should be no reason you have to put the wires from the wood bulb holder into the AW switch.
> 
> If you are asking a completely unrelated question from the wood plank holder, then the answer is no because you don't have a completed circuit with bulb resistance & current flowing to measure resistance.



The plank of wood is simply to use for re-setting the AWR HD.

The question about the AW switched tube is about measuring the voltage getting to the bulb in a light with his switch, and it seems that isn't the way.

Is there a way to do that, or does it have to be calculated from your charts?

Did you get my PM Sunday?


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## TKO (Dec 10, 2008)

LuxLuthor said:


> Rick, it may be brighter than many lights you have seen, but 5 x 3.3V = 16.5V @ 11.3Amps. With 220mOhms in AW D driver, and at least 30mOhms for other resistance, you are losing almost 3 volts (.25 Ohms x 11.3A = 2.83V).
> 
> The default spec of the bulb is 15V @ 10A giving 5600 bulb lumens. However nice it looks to you, it is being underdriven at less than 14 Volts. Put 5 Emoli 26700's in it, or a 6th A123, and you'll see what it should look like. With various 2000+ lumen output bulbs, quite honestly they all look white and bright to our eyes, so I'm not questioning what you see.
> 
> If you like it the way it is now then by all means, enjoy it. My point is to underscore that this issue of resistance losses is real, and has an effect on the bulb output and color. Most of these bulbs are not meant to be underdriven vis-a-vis light color and lumen output.


 
Lux,

Thank you for the detailed information. Your explanation makes perfect sense and is appreciated.

Many thanks for the clarification.

Best Regards,

Rick


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## LuxLuthor (Dec 11, 2008)

TKO, thanks for follow up. We have all been there. I knew absolutely nothing about any of this before picking up this hobby, so you just add tidbits at your own pace, and have it be fun.



donn_ said:


> The plank of wood is simply to use for re-setting the AWR HD.
> 
> The question about the AW switched tube is about measuring the voltage getting to the bulb in a light with his switch, and it seems that isn't the way.
> 
> ...



OK, now I see the relationship of the plank is to resetting the AWR HD.

Back to the AW switch. Take a look at my first post in this thread that I linked earlier. Basically in your previous question, you are still only measuring the Vbat from the AW bipin holes. I remember having the same exact question, so I understand how you were trying to figure it out. Best way to reinforce the concept of Vbat is to measure voltage of batteries in contact with each other. Put them in the tube, cap, and measure voltage in AW switch bipins. You will see it is nearly the same.

I just did tests again with a 3 x 17670 FiveMega 1.5D that direct drives a 1331 bulb. The *external 3s battery holder has Vbat of 12.42V. *

Put in the light without bulb, AW gives *12.35V / 12.44V / 12.42V* on its *Low/Med/High *settings. I don't know enough about how his driver works with just measuring Vbat to explain those slight variations in voltage, but they are all very close to Vbat of external FM 3s battery holder.

Now I put in the bulb, and some dark sun glasses  and with my Fluke 179 (RMS) DMM, I can just get the needle tip leads touching alongside 1331 bulb leads without a fancy "plank" setup. I* now get Vbulb readings of: 3.88V / 6.79V / 10.97V on LMH*

The Vbulb represents the PWM (pulse width modulation) effective "practical" voltage of 30%/60%/100% settings AW uses for L/M/H. The basic concept with PWM is the voltage delivered to the bulb pulses on/off at high frequency rates so you don't see it as blinking, and has a net effect of increasing the % of frequency "duty" cycle spent in "on" mode at (30% vs. 60% vs. 100%) higher settings.

Now if we know Vbat is 12.42V and Vbulb is 10.97V (using the High-100% on PWM), then I have a voltage loss due to resistance of 1.45V.

Now, to figure out how much resistance is causing that 1.45V drop, we need to know the current running through the completed circuit with bulb burning at around 11-12V. You can measure the current with method in my above linked post, or just use my destructive charts which was also measured accurately (with a shunt). The 1331 bulb chart is here, and we are using roughly 2.15 Amps.

So now we use Ohms Law of V=IR and solve for "R" to get 1.45V/2.15A = 0.67 Ohms or 670 mOhms in my otherwise stock setup--which is pretty high, but not unexpected.

If I were to use an AWR Hotdriver, I could do some resistance fixes, and set the Vbulb at around 11.0 to 11.2V and keep output at that level vs. direct drive drop off as battery voltage drops.


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## donn_ (Dec 12, 2008)

I've now graduated to making a 633  but I don't know why.

I just received my bulbconnection.com order, popped open a 633, and stuck it in a socket. 6xA123 cells, an AW switch and an extra junction in the body for length.

5 seconds on low, no problem. 5 seconds on medium, no problem. 1 second on high (incredibly bright!) and 

This setup should be nowhere near the flash point for a 633. Should I have let the bulbs come up to room temperature first? It's low 40's outside today.

Very frustrating.

============

Lux..thanks for the explanation. I'll have to try that. I just bought a pair of test leads with very small retractable wire hooks, for my 179. They should work for measuring Vbulb.


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## donn_ (Dec 12, 2008)

Further results lead me to think I should have let the lamps warm up, although I would think 10 seconds between low and medium would do that.

The 6xA123 string measures 20.01V.

I just tried a string of 5xEmolis, measuring 19.97V. The only other difference was 1 less junction in the body, but added a small aluminum spacer. It worked fine.

Confusion reigns!


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## modamag (Dec 12, 2008)

donn,

Did you startup with low-med-high or was it directly softstart to high?

Hot off the charger the M1 cells will be @ 3.5V/cell for a short period. That's 21V total minus 3V for the switch the bulb will see about 18V. *RIGHT AT THE FLASH POINT* Maybe drain them a little first.

How about the 5x Emoli. Did that blow.
Fresh off the charger these should be 3.9V/cell @ 10A draw.
The bulb will see about 16.5V. *These should not blow*

I'm confused.


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## donn_ (Dec 12, 2008)

Jonathan...see Vbatt measurements for both 6xA123 and 5xEmoli in post #40.

In each case, I walked it up through low and medium before going to high.

The Emoli string worked fine in high..no  Real bright light, too!


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## modamag (Dec 12, 2008)

Ah, I had to read it more carefully. So no 
8K lumens isn't all that bad


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## LuxLuthor (Dec 13, 2008)

Donn, your 633 on 6 x A123 with Vbat of 20.1V depending on resistance is going to flash the closer you get to the 18.0V that I found. That also assumes that there is no variation in batches of bulbs. I always ran at least two bulbs to make sure the flash point was consistent.

Another thing people need to look at is when you choose a bulb with low life of like 50 Hrs, and then see the small window from default to flash point...these are more delicate bulbs, and I would steer you towards the 16.5V range. 

To see the difference, look at the range you have with the IRC bulbs, or the 64458 bulb. You have to REALLY want to flash those bulbs with reckless overdriving. They have 4,000 hrs on default rating.

So my axiom here is if you choose a bulb with balls, you won't lose your own while overdriving. :devil:


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## Alan B (Dec 17, 2008)

donn_ said:


> Ha! I've been watching that, AW's threatened M6 soft-start 3-level switch, and his semi-threatened regulated switch. Alan B's thread is... How in the world will y'all get that 8" square circuit board Will's playing with into a flashlight?!?
> ...



donn_: The boards can easily be made small enough for flashlights. Here is my first attempt, small enough to fit in a D mag, using only through-hole parts and a huge high power FET. This board is designed to replace the switch in a D [email protected], and the three button board installs through the pushbutton hole for calibration/adjustment. In normal use it is replaced by a single pushbutton board and covered over with the rubber pushbutton cover.

The board Jim is designing with SMT parts will be much smaller.

-- Alan


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## Alan B (Jan 19, 2009)

LuxLuthor said:


> ...
> 
> Back to the AW switch. Take a look at my first post in this thread that I linked earlier. Basically in your previous question, you are still only measuring the Vbat from the AW bipin holes. I remember having the same exact question, so I understand how you were trying to figure it out. Best way to reinforce the concept of Vbat is to measure voltage of batteries in contact with each other. Put them in the tube, cap, and measure voltage in AW switch bipins. You will see it is nearly the same.
> 
> ...



Some of that resistance may be internal to the batteries as well, unless the 12.42V was measured while under load (it seems to have been measured without load).

Measuring the output of the PWM driver with no load produced inaccurate readings. There needs to be a minimum amount of load to get good square waves, just a meter is such high resistance that the voltage doesn't get to zero and 'floats' between the ontimes. Use a 1K resistor across the probes to draw a few milliamps and clean up the waveform. To see what is happening use a scope (a soundcard can do this pretty well also with proper interface and software).

Driving the bulb makes the pulses no longer quite square which makes these formulas slightly incorrect. They should still be close, but the battery voltage used must be the loaded battery voltage, not the unloaded voltage.

Use the DC (average) range of the meter, not the AC (or AC RMS) ranges. If the meter has an AC+DC RMS that is the best, but you can use the DC (average) range and do the calculations to get the RMS values.

/* Formulae
*
* 1) VbattDC^2 * Duty_cycle = VbulbRMS^2
*
* 2) VbulbRMS = VbattDC * sqrt(Duty_cycle)
*
* 3) Duty_cycle = VbulbRMS^2 / VbattDC^2
*
* 4) VbulbMEAN = VbattDC * Duty_cycle
*
* 5) VbulbRMS = sqrt(VbattDC * VbulbMEAN)
*
* 6) VbulbMEAN = VbulbRMS^2 / VbattDC
*/

So RMS bulb voltage = Loaded DC Battery voltage * square root (0.30) for 30% duty cycle, and so on.

-- Alan


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