# shining beam 2500mA driver wiring?



## jez (May 14, 2010)

Hello guys,

Newb alert!

I've searched for my answer and checked FAQs and I only seem to get lots on sandwich driving with diagrams but nothing on basics

Can someone point me in the right direction of where to solder my wires on to this driver.

It already has red and black on there which i'll replace and I'm guessing these are the LED supply and return?
So I'll need the battery positive and negative locations.

It's going in a 3d NiMH maglite with P7.

Thanks very much

Jez.


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## ^Gurthang (May 15, 2010)

Welcome to CFP! Glad to have you aboard.

The driver: The red goes + to the LED, the black is - [neg] to LED

on the base: outer ring is - [neg], inter pad is + 

You don't indicate if the emitter is bare or mounted on a star, keep in mind that the P7 base is + so if you're going "bareback" you'll need to keep the emitter isolated from ground using a non-conductive adhesive. 

Do a search in this forum for plenty of [email protected] builds & tutorials. Good luck and have fun.


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## ti-force (May 15, 2010)

I know Gurthang already answered your question, but I though I'd include a picture that I put together a while back:


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## ^Gurthang (May 17, 2010)

Ti,

Nice pic of the driver board. That should really help the OP.


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## ti-force (May 17, 2010)

^Gurthang said:


> Ti,
> 
> Nice pic of the driver board. That should really help the OP.



Yeah, I seem to understand better when something is explained and a picture is made available too .


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## jez (May 17, 2010)

Many thanks for the replies 

Next problem is that with 3 fully charged D cells on max setting it is only drawing 1.5A not 2.5-2.8A???

I have the 3 modes and memory works just low current on high?

I bought 2 boards and both do the same thing?

I'm using 3 ansmann 10000mAh NiMH cells for info.

The P7 is Arctic thermal glued to one of setapong's P7 HAIII heatsinks.

Hope you can help

Jez.


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## Mettee (May 17, 2010)

Can you post a pic of the actual board you have in your hand?

Does it have little black chips on both sides?

Chances are you got the XPG boards those are 1.5 amp boards.


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## jez (May 17, 2010)

Hi Mettee,

My photobucket account is messing around but the board is double sided.

http://www.shiningbeam.com/servlet/the-132/3-dsh-Mode-Regulated-Circuit-Board/Detail

My boards however have the 2 legs on the atmel board covered by the red wire in the link soldered together? 
Do you think this is right? There are 8 off 7135's. 1 off is an L7135 with 0944 under it, 1 has 35x under it and the other 6 have 35s under them.

Does this help?

Jez


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## jez (May 17, 2010)

Forgot to add that I took the current measurements at the tail cap and also output from driver to LED.


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## uk_caver (May 17, 2010)

Do you know what the Vf of your P7 is at various currents? (only really possible to measure accurately if measuring voltage +current at the same time).

Is the ~1.5A stable, or does it fluctuate?


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## jez (May 17, 2010)

uk_caver,

The 1.5A is stable.

The P7 is a W724C0-DSWOI from shdwkeeper so has a Vf bin of 3.25 - 3.5v

Can you tell me how I go about getting the figures your after?

thanks

Jez


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## ti-force (May 17, 2010)

What meter are you using? Certain meters aren't that accurate when measuring DC current.

Are you using alligator clips or anything like that or just leads?

Are all contact points clean (you might want to clean them with rubbing alcohol).

What gauge wire did you use from the switch to the driver?

How long are your wires from the switch to the driver?

Do your solder joints look good?


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## jez (May 17, 2010)

Meter is a Fluke 179 true rms meter
24 gauge wire used. 1.5" from switch to board and about 2" from board to LED.
Croc clips for the meter.

Any ideas what the two soldered pins on the ATMEL chip do?

Thanks


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## ti-force (May 17, 2010)

Well, I don't think it's your meter . Do you have another set of batteries you can try?

Did you leave the pre-soldered LED + and LED - wires on the driver or did you replace them with 24 gauge wire? It sounds like you did, but I'm just checking. I don't think the small wires would cause that much resistance (typically 2.5A instead of 2.8A), but it is added resistance.

Does the light flicker or anything? Soldered joints?


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## jez (May 17, 2010)

Yeah I changed the pre soldered ones for 24 gauge.

Just seems odd. only 4 wires to put on and it doesn't seem right. 

I must be missing something, maybe a shorting link of some sort somewhere???????

I might get a KD one sent to me and try that just to see i'm not being a numpty.

Ta


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## ti-force (May 17, 2010)

When you soldered Battery - to the driver, did you solder near any of the gold stars on the spring side of the driver?

Any chance you could take some pictures of the soldered wires on the top and bottom of the driver? I know it's aggravating, but.....


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## ti-force (May 17, 2010)

jez said:


> Hi Mettee,
> 
> 
> My boards however have the 2 legs on the atmel board covered by the red wire in the link soldered together?
> ...



The two soldered legs on the ATMEL chip is normal.


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## jez (May 17, 2010)

My work camera is pants but here are the best I could get.











Off to bed now it's late UK time :candle:

I'll pick this up again later

Thank again for your suggestions.


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## cmacclel (May 17, 2010)

Looks like you have a high VF LED. Bypass the driver and see what you draw for current.

Mac


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## uk_caver (May 18, 2010)

jez said:


> The P7 is a W724C0-DSWOI from shdwkeeper so has a Vf bin of 3.25 - 3.5v


If that's the standard Vf, isn't that at 1400mA.
From the datasheet, it looks like the Vf difference between a P7 at 1400mA and one at 2800mA is something like an extra 0.2-0.25v.


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## Mettee (May 18, 2010)

That negative solder joint might be touching that star it looks like but I cant tell for sure. Ti force had that happen to him a while back.

I usually clip the gold spring off and then de-solder what is left as well. Its hard as heck to get off unless you do that because the heat
just gets soaked up. But I would not say that that is the issue at all.

Let me test one I have with a low VF P7(dsvni) and I will let you know what I get with mine. I have a few of the SB boards.

drew


OH and you might want to resize those images or the mods will tell you to.


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## jez (May 18, 2010)

Thanks for the warning Mettee on the re size!

I'm going to DD the led later and see what I get.

I soldered the +ve to the board in the middle of the spring as knowing my luck I would have ripped the board to pieces.

I thought the stars just changed the modes but they all had high?


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## Mettee (May 18, 2010)

The stars do change the modes but you have to cut the other trace and solder to another star to make it work, if you didnt do that and you also have solder on another star you may be having a problem....


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## jez (May 18, 2010)

OK, direct drive gives me 2.3A so does that mean that i'm losing the current through the driver and I should have got a boost driver instead?

about the stars, thanks.


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## uk_caver (May 18, 2010)

Taking the nominal ~120mV dropout voltage of the AMC7135 chips, and applying it to the slope of the P7's voltage/current graph at the relevant current, assuming that the battery voltage hadn't changed meaningfully with the different loads, and that any extra connections were negligible resistance, that 120mV would look likely to cost ~750mA compared to direct drive, which seems pretty much what you found

However, one thing that should be remembered is that the meter measuring the current also introduces some resistance.
On my cheap and relatively cheap meters, on the high current ranges, that resistance seems to be something like an extra 0.1ohm (300-350mV at 3A)
From the manual, it looks like your Fluke meter is rather better - around 0.037 ohm, (assuming probe contact is perfect?), but even then, that'd *still* be costing you 50+mV at 1.5A, enough to quite meaningfully change the current that the LED could end up taking, maybe by ~350-400mA.

(Doing direct drive current measurements, or doing linear regulator current measurements when there's no voltage 'headroom' to play with can be a real pain.)

Also, have you actually run the P7 for any length of time, or just done very cautious short bursts?
I found with a couple of P7s I bought that the Vf permanently dropped after even only a few minutes of 'burning in' at ~2.5A, even with the LEDs properly heatsinked. That just seems to be something that generally happens.
Also bear in mind that the Vf will reversibly drop a little as the P7 heats up in use, so unless heatsinking is perfect, it could be that without the meter in place, you could possibly get a rather higher output than 1.5A even with the driver in place, at least on fresh cells.

Would you have any way of checking that out (like a lightmeter, or a digital camera with manual settings that you could use to illuminate a scene and take both cold, meter-in-circuit and warm, no-meter-in-circuit pictures with)?

Even if that was more encouraging, it could still mean that you'd lose brightness as the cells discharge, possibly fairly significantly, but things might not be quite as bad as they might seem with a meter in circuit.

With the meter in place, have you done cold and warm readings for direct drive and/or driver-based drive?


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## jez (May 18, 2010)

[/COLOR]


uk_caver said:


> Taking the nominal ~120mV dropout voltage of the AMC7135 chips, and applying it to the slope of the P7's voltage/current graph at the relevant current, assuming that the battery voltage hadn't changed meaningfully with the different loads, and that any extra connections were negligible resistance, that 120mV would look likely to cost ~750mA compared to direct drive, which seems pretty much what you found
> 
> However, one thing that should be remembered is that the meter measuring the current also introduces some resistance.
> On my cheap and relatively cheap meters, on the high current ranges, that resistance seems to be something like an extra 0.1ohm (300-350mV at 3A)
> ...


I'm sorry but being new to this the camera shots look a little beyond me at the moment. Not being very helpful am I?

Mettee, in another thread ssc P7 questions you recommended a D bin P7 for holdthat1 who was also going for NiMH.
Do you think that would help?

Thanks


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## Mettee (May 18, 2010)

I thought you said you had a D bin from shadowkeeper so you should be fine there.

You could also try adding a 4th battery in there to see if that changes the amps you see at the tail. 
That will combat voltage drop for a test. You never know maybe you have a J bin P7 with a higher VF.

I have not had a chance to test a set up here yet.


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## jez (May 18, 2010)

The led is this one 
Seoul Semiconductor's P7 Emitters (W724C0-DSWOI)
"AVAILABLE" 
Flux bin D: 800 - 900 lumen output at 2.8A
Color bin SW0: 6050K
Vf bin I: 3.25 - 3.50V

Is this a D bin or I bin? The other one that is out of stock also says flux bin D but Vf bin J.

I'm going to have to leave the LED direct drive until I come back on shift on Sunday but I will try the 4 d cells then to see what I get.

Perhaps this was not as straight forward as I hoped? Huge learning curve though 

I'll keep an eye on the thread to see what you might be able to come up with in the mean time.

Thanks again for helping out a newb

Jez.


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## ti-force (May 18, 2010)

jez said:


> The led is this one
> Seoul Semiconductor's P7 Emitters (W724C0-DSWOI)
> "AVAILABLE"
> Flux bin D: 800 - 900 lumen output at 2.8A
> ...




* Yes, it's definitely a learning curve:thumbsup:.


As for your emitter information. You need to look at the data sheet for each emitter. DSWOI is actually 3 different bin codes for your emitter. The first letter, "D" is the luminous flux bin code. Below is the corresponding chart:*











*
The next 3 letters, "SWO" is the tint bin code. Below are the corresponding charts*:














*
The last letter, "I" is the forward voltage bin code. Below is the corresponding chart:*






*
Maybe this will help you make better sense of things. Unfortunately, every emitter manufacturer labels their emitters a little differently, so you will have to read the data sheet for each emitter to make sense of all of the bins that are labeled:thumbsup:.*

BTW, posted images can have a maximum size of 800x800. As long as you stay exactly 800x800 or smaller, you're good to go.


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## daytec (May 18, 2010)

I am running the same driver with a linger special . With a single 18650 i get around 1.5a with two 123's {6v} i get a full 2.5a. Nailbender gave me this tip [thanks dave]. try raising the input volts. hope this helps.........marty


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## jez (May 18, 2010)

Thanks ti-force & daytec.

really wanted to keep to 3 nimh as it's easier to look after at work - free equipment ;-)

I did try 3 alkalines and 4.5V ish still gave 1.5A at switch on but i'll try 4 nimh and see if there is a difference.


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## Mettee (May 18, 2010)

so try a 4th battery like many of us have said and see what that does...then go from there and post results.

If you are sure you have a DxxxI binned P7 that is not the problem. If you are running alks that may be part of the problem, try NIMHs.


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## jez (May 19, 2010)

Mettee,

I am running NiMH, 3 x 10000 mAH Ansmann. just tried the alks for the higher voltage.

Good to hear P7 is ok.


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## ti-force (May 19, 2010)

jez said:


> Mettee,
> 
> I am running NiMH, 3 x 10000 mAH Ansmann. just tried the alks for the higher voltage.
> 
> Good to hear P7 is ok.



The alkalines will have severe voltage sag and the current reading you got is probably the best they will do. Try 4 NiMh's and your problem might be solved. I wonder if a different brand of NiMh's would perform better than the ones you're using? Just wondering; I've never heard of the brand you're using, but I have never used NiMh's much, so I was just curious.


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## Mettee (May 19, 2010)

Ti maybe he can try a single lithium ion, what do you think? At least if he has one to try...

I had good luck with alks and I used them for a while with my very first build that was a P7 build. I am tending to think it might be something else that is wrong...just sayin...

Ok I tried my P7 with SB board...both a single lion, 3-4 alks and/or eneloops provide over 2 amps. Yes the 4 alks has been drained a bit so I did not over voltage the board, and I did also try with 3 new fresh ones. So i am lost as to what the issue is. 

How is the solder connection to the led? Unless you tried your 4th nimh and that solved the problem.


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## ti-force (May 19, 2010)

Mettee said:


> Ti maybe he can try a single lithium ion, what do you think? At least if he has one to try...
> 
> I had good luck with alks and I used them for a while with my very first build that was a P7 build. I am tending to think it might be something else that is wrong...just sayin...



I can say this about the Li-ion setup. I have a 2d Mag, with a 7135 based driver (9- 7135 chips for 3+A current), a CSXPI SSC P7 emitter, using 1- Batterspace 26650 and it works flawlessly. But I've learned that the internal resistance of batteries can play a serious role in delivering the current. AW batteries almost always perform as expected, but I had problems with some DX D-sized Li-ions. I have 2 of those, and neither one would deliver over 2.5A in this light, but the Batteryspace delivers over 3.1A.

I only use Lithium batteries, but that's personal preference. Also, I can't recommend the use of Li-ion batteries without giving a warning of their dangers in the same sentence. If anyone reading this isn't familiar with the dangers of misusing or neglecting Li-ion batteries, I strongly recommend you research that prior to using them.

It's really hard to diagnose a problem like this through a computer, but we're trying. If the raised input voltage doesn't change anything, we'll try something else, and hopefully someone will figure out what's causing the problem:thumbsup:


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## Essexman (May 19, 2010)

Hope you can sort this out?

All is not lost, if 4 NiMH cells work the driver correctly, you can still use your 3D mag. You can fit 4 C NiMH into a 3D mag with ease, it's a common mod.

Let us know how you get on.


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## jez (May 20, 2010)

I really appreciate all your efforts with this.

Was 2.3A about right for direct drive?

The torch is at work right now and I can't get to it till Sunday but getting this list of things to try is promising.

I soldered the led using both the legs with the wire laying across them as it was easier this way without a third pair of hands. Will that make a difference?

How is the front of the board connected to the back? Could one half of the boards regulators not be connected somehow?

I have found 4 C size NiMH at home of the same make Ansmann so i'll take them to work and try those also.

I'll try different wire too and see what happens. Can't imagine a different make of 24AWG will make much difference but maybe a fresh go at soldering will give better connections?

Mettee did you measure the current through the tailcap?

Thanks Guys


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## Webbstarr (May 20, 2010)

I have the same boards from SB but mine do not have what looks like a small resistor soldered below the spring on post #3. could this be the issue? im curious because i have the same hardware and want to build one as well. i however will be using imr 26650's. good luck


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## TorchBoy (May 20, 2010)

Mettee said:


> You could also try adding a 4th battery in there to see if that changes the amps you see at the tail.
> That will combat voltage drop for a test.


That should do it. Last month I made a headlamp using AMC7135 drivers that on high feeds three XP-G LEDs at 1 A each (3 A total). Unfortunately there is voltage voltage drop all over the place and with a bit of voltage sag from three NiMH (Eneloops) the LEDs were only getting a total 1.0 A or so, or maybe as much as 1.2 A hot off the charger. I added a 4th NiMH cell and that brought it up to the full 3 A I was expecting. :twothumbs It still drops out of regulation before the cells are empty, though.

Good luck with the 4 C cells.


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## jez (May 20, 2010)

Hi Webbstarr,

If you mean the small resistor going to the outside ring then that is a mod to change the modes of the board but doesn't change the output.


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## Mettee (May 20, 2010)

jez said:


> I really appreciate all your efforts with this.
> 
> Was 2.3A about right for direct drive?
> 
> ...



Yeah I did tail cap current and all were up over 2.xxx amps no matter the combo. Even the alks....just not much over 2  I did not direct drive it since your set up is not direct drive.

Sounds like your wire, and the soldering on the P7 are perfectly fine. I would look closely at the board more and its connections. Even the smallest dab of solder in a place it should not be will throw things off.

And the 4th cell test as well...didnt want to forget that.

drew


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## jez (May 23, 2010)

Righty-o

With the driver back in place and 3d NiMH the amps are 1.7 so up from before a little, whether that is down to better soldering or the fact the batts have had a recharge through them I don't know.

Threw a 4th d cell on top and bang 2.8A which is good as I know the driver is working fine.

Should this driver work with 3 cells? If it does then perhaps my cells are not up to it.

I have 4 c cells at home so i guess i'll be modding for that now.

Annoying as i'd paid out for the D's and now can't use them unless at reduced power - mmm.

Might put some more cycles through the batts and see if they come up more as they are pretty much new.


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## TorchBoy (May 23, 2010)

jez said:


> Should this driver work with 3 cells? If it does then perhaps my cells are not up to it.
> 
> I have 4 c cells at home so i guess i'll be modding for that now.
> 
> Annoying as i'd paid out for the D's and now can't use them unless at reduced power - mmm.


Didn't we figure out that it almost certainly needed that extra cell for the voltage? And didn't your test confirm our suspicions?

Reduced power will give you longer runtime. Always a bright side, it's just that in this case it's a dimmer side for longer.


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## uk_caver (May 23, 2010)

For what it's worth, I got a couple of low Vf P7s (H bin) for a little photo flood light, and even with them, I'm pretty much on the borderline between 3 and 4 cells for full power.

Using 7xAMC7135s and running from 4xEneloop AAs, I get ~2.4A, and that current matches up with a measured initial 3.21V across an LED, dropping fairly quickly to ~3.13V as things warm up.

If I try running from 3 Eneloops, I get a measured ~1.55A with a meter in circuit, and ~1.65A if I stick two meters in parallel to drop the resistance. I guess I'd be getting ~1.75A with no meter present.
I do have quite a few contacts adding resistance in that setup, since that is running from 3xEneloops in a battery holder, with a lead running from a PP3 clip on the holder to another connector which then plugs into the light.

If I run from 3xNiMH 18650-ish cells, tagged and soldered, and with just one connector between them and the light, on a part-used battery pack maybe ~20% used, last charged a few weeks ago, I get 2.2A, and without the meter I'd probably be getting the full 2.4A, but only by a pretty slender margin.


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## ti-force (May 23, 2010)

jez said:


> Righty-o
> 
> With the driver back in place and 3d NiMH the amps are 1.7 so up from before a little, whether that is down to better soldering or the fact the batts have had a recharge through them I don't know.
> 
> ...



Well, at least you've learned about emitter vf right? Measure voltage at the emitter to find out what the vf of your emitter is. Just put the positive lead on the positive side of the emitter and the negative lead on the negative side, then turn the light on. Like TorchBoy said, we already though it was too little input voltage, and that the 3 cells you're using don't supply enough voltage, so measure the vf of your emitter, and that should show you why you need the 4th cell :thumbsup:. Oh yeah, don't look directly at the emitter or you will see dots for a while .


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## uk_caver (May 23, 2010)

ti-force said:


> Oh yeah, don't look directly at the emitter or you will see dots for a while.


I find sunglasses are very useful when doing LED work at decent drive levels.


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## ti-force (May 23, 2010)

uk_caver said:


> I find sunglasses are very useful when doing LED work at decent drive levels.



Great suggestion, thanks:thumbsup:


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## TorchBoy (May 23, 2010)

ti-force said:


> Oh yeah, don't look directly at the emitter or you will see dots for a while .


Managed to do that just after wiring up my first Cree XP-G.


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## jez (May 23, 2010)

Vf over LED is 3.35v.

I read somewhere that you need 0.6v higher than Vf to run the driver so i'd need at least 4v then? 
Did I understand that right? 


You would happen to have a link to the 4c conversion as I've lost that too!


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## uk_caver (May 23, 2010)

jez said:


> Vf over LED is 3.35v.


What current is that measured at?
(That might be hard to say in a 3-cell setup, unless you're simultaneously measuring the current, given how an ammeter could affect the current being drawn.)


jez said:


> I read somewhere that you need 0.6v higher than Vf to run the driver so I'd need at least 4v then?
> Did I understand that right?


The AMC7135 driver chips only specify a typical drop of 0.12V at max current (350mA/chip).
The 0.6V figure might have been making allowances for other losses or changing battery voltages, or referring to a different driver,


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## jez (May 23, 2010)

Sorry, I got the same Vf for 3 cells at 1.9A and 4 cells at 2.8A

Took the Voltage across LED then did tailcap current at same setting. Haven't got two meters to do at the same time.

Should they be different?


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## uk_caver (May 23, 2010)

They might be expected to be different by about 0.1V

However, one confounding factor can be the heat issue - at the higher current, the LED will end up warmer, which will lower the Vf a little.


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## Mettee (May 23, 2010)

jez said:


> Righty-o
> 
> With the driver back in place and 3d NiMH the amps are 1.7 so up from before a little, whether that is down to better soldering or the fact the batts have had a recharge through them I don't know.
> 
> ...




For sure the addition of the 4th battery shows the board is fine, and in fact they are up to the task you just need that 4th cell to give it that little push to the happy zone.

That is good news at least...you made some progress.

And yes I think you need a little more than 4v...think of it as if you were running a single Lion cell. They usually start at about 4.2 off the charger.


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## TorchBoy (May 23, 2010)

uk_caver said:


> The AMC7135 driver chips only specify a typical drop of 0.12V at max current (350mA/chip).
> The 0.6V figure might have been making allowances for other losses or changing battery voltages, or referring to a different driver,


Or possibly got confused with the ~0.6 V drop across the polarity protection diode.


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## jez (May 24, 2010)

Me again ,

I'm sure your all fed up with this by now but i've come across something else.

With 4 c cells powering I get 2.8A tailcap current for about 15secs then it rapidly drops all the way down to about 0.7A

The same happens with 4 d cells.

However, with 3 d cells powering I'm getting 2.1A now but it holds steady.

Am I suffering from bad heatsinking i.e too much adhesive on the led?

Thanks

Jez.


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## Justin Case (May 24, 2010)

It sounds like 6 out of your 8 AMC chips have hit their thermal limit and the built-in thermal protection kicked in and shut down those chips.

Have you tried eliminating sources of parasitic resistance so that you can run with 3xD NiMH in regulation?


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## jez (May 24, 2010)

Hi Justin,

I've done the tailcap spring fix to reduce the resistance there.

I'll look at the switch too.

I could always try 22gauge instead of 24 as well.


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## TorchBoy (May 24, 2010)

Justin Case said:


> Have you tried eliminating sources of parasitic resistance so that you can run with 3xD NiMH in regulation?


I dare say that'll only get it to run in regulation for a short time when the 3 cells are freshly charged. Because four flat NiMHs will give fewer volts than 3 fully charged NiMHs, 4 cells will likely drop out of regulation at some point too. How much current does it provide when the 3 or 4 batteries are half or almost completely flat? Is either OK?

Justin is probably right about the thermal limiting, but I didn't get that in my headlamp. Can you cool them easily?


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## Mettee (May 24, 2010)

I have run tons and tons of these with no "cooling" at 3.0 amps and they never have problems. I have done 1 sandwich that had a problem and I was never able to see that one again after I sent it off. 

you would also think that with 3 SST-50s they would hit a thermal cut off before this light would....especially at over 4 amps.


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## TorchBoy (May 24, 2010)

The total current from an array of AMC7135s is much less of an issue than how many volts each AMC7135 is dropping and how they can get rid of their heat.


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## ti-force (May 24, 2010)

Mettee said:


> I have run tons and tons of these with no "cooling" at 3.0 amps and they never have problems. I have done 1 sandwich that had a problem and I was never able to see that one again after I sent it off.
> 
> you would also think that with 3 SST-50s they would hit a thermal cut off before this light would....especially at over 4 amps.



What was your voltage in? When v in exceeds vf, the excess voltage is burned off when using these drivers. This creates heat which reduces efficiency. If his cells have a nominal voltage of 1.2v each cell, and he's using 4 cells, the total voltage is 4.8v. If vf is 3.35v, and v in is 4.8v, the driver has to burn off 1.45v. This is a rough estimate to get waste heat: 1.45v x 2.8A = 4.06 watts of waste heat.

**EDIT* Sorry TorchBoy, I guess you and I were both typing at the same time. *


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## TorchBoy (May 24, 2010)

Your example is much better than my explanation! If the cooling the board is getting is reasonable, perhaps it doesn't need a complete extra (4th) cell to get the volts for full output. That's a bit awkward. Perhaps four cells could be used, but with some _extra_ resistance introduced somewhere. :shrug:


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## Mettee (May 24, 2010)

I understand what you guys are saying.

I just dont think that is enough to make it do what it is doing...he has a problem with 3 cells. charged they should be over 4v and should easily supply the voltage to hit is mark of 2.8a. Something else is happening here that is being missed. I used 3 AA eneloops with the same board and a DxxxI P7 and it was over 2.xx amps for the whole test. With 4 it was still 2.xx amps the entire test. I can not remember what voltage it was for both. But I have also used 2 lion on these boards just to see what it would do and it never acted like described by the OP(admittedly not for long periods). And I would figure that is an over voltage above the VF if there was ever any.


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## ti-force (May 24, 2010)

TorchBoy said:


> If the cooling the board is getting is reasonable, perhaps it doesn't need a complete extra (4th) cell to get the volts for full output. That's a bit awkward. Perhaps four cells could be used, but with some _extra_ resistance introduced somewhere. :shrug:



If it were me, I'd switch to 1x Batteryspace 26650, but that's the setup I have, which is why I like it, plus I have a 2D Mag, which is shorter. Also, I understand that Li-xxxx's aren't for everyone.


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## Justin Case (May 24, 2010)

TorchBoy said:


> I dare say that'll only get it to run in regulation for a short time when the 3 cells are freshly charged. Because four flat NiMHs will give fewer volts than 3 fully charged NiMHs, 4 cells will likely drop out of regulation at some point too. How much current does it provide when the 3 or 4 batteries are half or almost completely flat? Is either OK?
> 
> Justin is probably right about the thermal limiting, but I didn't get that in my headlamp. Can you cool them easily?



Silverfox's discharge curves for Accupower D NiMH show that those cells can hold ~1.25V for ~3A load for probably about 2 hours. So I would say that if you have a 3D Mag with low resistance and a suitable Vf P7, you should be able to run in full regulation for plenty of time.

The OP's Mag does not appear to be low resistance, however. He can get only 1.7A at the tail when using the SB AMC driver and 3xD NiMH. Or his P7 does not meet the I Vf bin spec. Or both. Whatever the reason, it seems clear that 3xD NiMH can't provide enough Vbatt in his 3D Mag, when they should be able to do so easily.

How is the SB driver heat sinked? To the LED heat sink? To the Mag tube? Hanging free?


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## TorchBoy (May 24, 2010)

That graph doesn't look too bad. Did we have a figure for what the 3 cell battery voltage under load is in this situation?


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## vestureofblood (May 25, 2010)

Hi jez,

I realize some of this may have already been covered, but here is my 2 cents.

Let me start by saying that it is possible you are getting a bit more current than you think when the light is assembled. Measuring current through the tiny pinpoints of your DMM leads, combined with the internal resistance of said device is going to cause a drop in current.

When you add a 4th cell what you are doing is pushing past all of this extra resistance with a higher voltage.

A quick example. 

I hooked up an SST-50 DD on 1x imr 18650. Through the leads of my DMM I could measure about 3.6 amp after the emitter warmed up. I knew I was getting more current through the light with the tail cap on for reasons I wont take the time to explain here. So using some very thick copper wire ( like 14 G I think) I made a set of leads and just plugged the thick wire into the DMM and touched the other ends to the light and cell. Instantly the current shot up to over 6 amp where I had to disconnect.


You may be having more than just measurement problems though.

If you realy want to get this light to run at the full 2.8 amp on 3 cells it can be done.

I recommend using Accupower precharged cells because it seems to me like in the case of eneloops and Duraloops, that the precharged cells drive emitters harder and hold up under a load better (just MHO though).

I dont know anything about the brand of D cell you are using. If they are a lower quality off brand ( I am not saying they are) they may have very high internal resistance. 

For now lets assume your cells are good, and take a look at some other problem areas.

From what I gather you are sure that your emitter is a CxxxI bin, so the VF of the led is likely not your problem.

The first thing I would do is get some thick copper wire. Go bigger than you think you need, like 20G or so. 

I like to use deoxit gold solution on all metal to metal contacts where current flows as well. 

If you haven't done it already modding the tailcap for lower resistance with some copper wire or braid will help too.

And last but not least. Even running at only 3.6 volts it wouldn't hurt to heat sink the driver (on both sides if using the SB driver) You could use thermal epoxy to stick it to the base of the led heat sink, and then put an aluminum disc on the other side. This will not effect the current at start up so much, but after the light has run for a few minutes it will help stabilize the current.


I hope this helps. Sorry if I am being long winded, but I am confident this problem can be overcome.


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## jez (May 25, 2010)

Wow lots of replies to go through and great info in them.

I've not ruled out the cells being the problem. They are a German manufacturer and seem to have a good reputation.
http://www.ansmann.de/cms/businessdivision/consumroot/batteries-battery-packs/rechargeable-batteries-nimh/mono-d/10000-mah.html

The driver is just hanging free at the moment with no additional heatsinking.

It's frustrating for me having to ask all this as it seemed a fairly common and straight forward mod so problems should have been minimal.

For the driver heatsinking, do you glue the aluminium disc to the top of the drivers? No need to touch the actual circuit board? Now thats a newb question 

I've got hold of a second DMM if that helps for measurements.

I think I can change the battery wires for 20 gauge but I don't think these will go through the heatsink holes. Would just the bare conductor be ok for testing knowing the heatsink is HAIII anodised?

Thanks


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## Justin Case (May 25, 2010)

Mettee said:


> I have run tons and tons of these with no "cooling" at 3.0 amps and they never have problems. I have done 1 sandwich that had a problem and I was never able to see that one again after I sent it off.
> 
> you would also think that with 3 SST-50s they would hit a thermal cut off before this light would....especially at over 4 amps.



Thermal management is a tricky thing. If the setups are apples-to-apples, yes you would think that the OP's setup should work fine since higher-powered AMC setups have shown no problems.

Based on the scant evidence, this is probably not an apples-to-apples situation. Hence the OP's problems.

Possibly the AMC chips' mounting tabs are poorly sinked.

I'd run the light with its guts out in the open. Periodically feel the temp of the 8 AMC chips. If the light essentially cuts out within 15 sec, the test should be quick to perform.

With all of the various changes, re-measurements, and so forth, it's hard for me to keep track of the current status. Jez, am I correct that you are now getting 2.1A at the tail with 3xD NiMH? And you believe that you have a Vf of 3.35V at 2.8A, with the Vf and tail current measurements done separately? If that's correct, then you have a relatively low Vf P7.


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## Justin Case (May 25, 2010)

Mettee said:


> I understand what you guys are saying.
> 
> I just dont think that is enough to make it do what it is doing...he has a problem with 3 cells. charged they should be over 4v and should easily supply the voltage to hit is mark of 2.8a. Something else is happening here that is being missed. I used 3 AA eneloops with the same board and a DxxxI P7 and it was over 2.xx amps for the whole test. With 4 it was still 2.xx amps the entire test. I can not remember what voltage it was for both. But I have also used 2 lion on these boards just to see what it would do and it never acted like described by the OP(admittedly not for long periods). And I would figure that is an over voltage above the VF if there was ever any.


 
If the SB driver has to dissipate 4W of waste heat, that's a lot and the board should be heat sinked.

There appears to be at least two different problems, which manifest themselves when the OP runs with either 3xD or 4xD.

The first problem seems to be that Vbatt isn't enough to reach full regulation. That problem shows up when running with 3xD, since Vbatt has less margin. However, efficiency is basically 100%, so the driver has to dissipate very little waste heat. If the P7's Vf at 2.8A really is 3.35V, then the source of the problem has to be the Mag host. The OP has done a tail spring low resistance mod. I suppose the switch is next. Another easy thing to check are all of the solder connections. I doubt it is the 24 ga hookup wiring. Resistance per 1000 ft for 24 ga is 25.67 ohms. The OP previously estimated a total length of about 3.5" (0.29 ft) of wire. Thus, total resistance is about 0.0075 ohms. If the current is 2.8A, then the voltage drop is 0.02V, which is negligible.

The second problem is the light essentially cuts out (tail current drops from 2.8A to 0.7A) after 15 sec when using 4xD. Lacking any additional information, the tail current numbers suggest that 6 of the 8 AMC chips have shut down, perhaps due to thermal considerations. ti-force's calculation explains the issue -- a potential of 4W of waste heat that needs to be dissipated. Fifteen sec seems pretty quick to me to shut down, which possibly hints at a defective board. That's why I suggest checking the sinking of the mounting tab.

If you are going to get into mod'ing, I would recommend getting a bench power supply. You can find versions on the web for about $100 that can deliver up to 30V/5A. It makes it a lot easier to test your setups with known voltage/current inputs before you complete the assembly.


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## Justin Case (May 25, 2010)

jez said:


> For the driver heatsinking, do you glue the aluminium disc to the top of the drivers? No need to touch the actual circuit board? Now thats a newb question



I would heat sink to the wide tab of the 7135 case. Sinking to the plastic case itself isn't going to be very effective since the case is a poor thermal conductor.



jez said:


> I think I can change the battery wires for 20 gauge but I don't think these will go through the heatsink holes. Would just the bare conductor be ok for testing knowing the heatsink is HAIII anodised?



I doubt that switching to 20 ga wire is going to matter, but it can't hurt.

I personally would not take the chance with using a bare conductor unless I knew for a fact that the holes were also HA.

If you are just testing with 20 ga and the wire is too thick to fit through the heat sink feed holes anyway, then why not just go around the holes. Run the wire from the driver directly to the LED. If you plan on a permanent installation with the 20 ga, then I'd probably drill out the feed holes.


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## vestureofblood (May 25, 2010)

jez said:


> http://www.ansmann.de/cms/businessd...argeable-batteries-nimh/mono-d/10000-mah.html
> 
> The driver is just hanging free at the moment with no additional heatsinking.
> 
> It's frustrating for me having to ask all this as it seemed a fairly common and straight forward mod so problems should have been minimal.


 
Trust me we have all been there. While some mods go just as planned, other that seem simple can often turn up unexpected issues. But that is how we lern. Hmmm what is the saying.. Great salors are not made on a clam sea?



jez said:


> For the driver heatsinking, do you glue the aluminium disc to the top of the drivers? No need to touch the actual circuit board? Now thats a newb question


 
Correct just use a thin layer of arctic alumina or similar to glue it to the top of the chips, the heat sink does not have to contact the PCB.

For the amount of heat sinking you will need you could probly even just glue a couple of thick chunks of aluminum to the driver and not worry about attaching it to the body of the light.





This is a pair of the SB drivers wired in parallel for an SST-50. Just attach the wires so they lay flat and sticks out the sides.

You will have to remove the spring from the bottom of the driver, or drill a hole in the center of your heat sink.

One other thing I do to aid in better current flow, and to drastically reduce the risk of tearing off the electrical pads of these drivers is to attach the led pos wire to the end of the diode as well as to the + pad.

Here is a pic, the + end of the diode is right next to the + led pad.






jez said:


> I've got hold of a second DMM if that helps for measurements.


 
You could possible use both DMM in parallel to get a better idea of the current as mentioned by another member in this thread.

Here is vid that may help you understand what I mean about DMM resistance. 




jez said:


> I think I can change the battery wires for 20 gauge but I don't think these will go through the heatsink holes. Would just the bare conductor be ok for testing knowing the heatsink is HAIII anodised?


 
I agree with Justin on this, bare wire is not the best idea. If 22g will fit you could probly get by with that.

What gauge wire are you using now?


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## jez (May 25, 2010)

I've just tried 4 c's with it all hanging free and as the current started to drop I touched the regs on both sides of the driver and almost burnt my finger so they are getting damn hot. Guess that's that for 4 cells. Can't imagine any heatsinking stopping them cooking.

2.35A (tailcap) and 3.3 Vf (led) with 3 d's measured one after the other. Seems my d's are either getting better or something else is settling in?
regs are fine at this current to touch.


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## vestureofblood (May 25, 2010)

jez said:


> I've just tried 4 c's with it all hanging free and as the current started to drop I touched the regs on both sides of the driver and almost burnt my finger so they are getting damn hot. Guess that's that for 4 cells. Can't imagine any heatsinking stopping them cooking.
> 
> 2.35A (tailcap) and 3.3 Vf (led) with 3 d's measured one after the other. Seems my d's are either getting better or something else is settling in?
> regs are fine at this current to touch.


 

Actualy you would be surprised how far an 1/8 of an inch if aluminum will go as far as heat sinking. 

I use 3 of these driver in parallel sinked to good size aluminum disks, and it pegs out with a stable current of 8.4 amp on high with the use of 4 C cells.


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## jez (May 25, 2010)

I've just mangled together 2 aluminum heatsink discs a little bigger than the diameter of a c cell and taped them tightly either side of the driver.






With 4 c cells the current held for a little longer then dropped again but slower.
The sinks got very hot too.

Vestureofblood, how you got two of these with a couple of sinks running amazes me.

Also I checked the soldering of the mounting tags.


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## Mettee (May 25, 2010)

So you got 2.35amps so far with 3 cells. If you were measuring that with a DMM with small leads that might actually be 2.8amps but it is unable to read that due to the smaller leads on the DMM. 

So it seems everything could be fine, just a misreading throwing you off. What is the brightness like. Seems no one has asked that.

And yes you might get "settling in" as you burn in the led the VF lowers slightly.


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## ti-force (May 25, 2010)

According to the specs at Flukes website, your 179 meter should be pretty accurate when measuring DC current. Has anyone had any negative experience with a Fluke or other nice meter that would suggest otherwise? Just curious. The specs for DC current accuracy with the 179 meter are: +/- 1.0%+3, so just say you're getting 2800ma. Using the accuracy specs, wouldn't 1.0%+3 = 2800ma x .01 = 28ma, 28ma + 3 = 31ma, 2800ma - 31ma = 2769ma. If I'm figuring this correctly, that's not much drop from this meter.

You stated earlier in this thread that you're using alligator clips during current measurements right? Are they alligator clip leads, or alligator clips that push on to the test leads? If they're the push on type, remove them and take another reading to see if the reading goes up any with 3xNiMH's. I don't know how much voltage drop those clips create, but these things add up. Also, I can't remember if you said or not, but did you clean all of the contact points with alcohol? The Mag body (where the tail cap makes contact with the body), the tail cap (where it makes contact); both ends of the spring and the contact point for spring to tail cap.

Don't feel bad about asking these questions; you can't learn if you don't ask right. I had issues with my first SSC P7 build too, in fact, that's where I cut my teeth, and I've been learning ever since, although, the basics make a lot better sense to me now. I have to thank Linger, JustinCase and TorchBoy for helping me a LOT with my problems. If not for them, I'd still be lost:thumbsup:.


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## Justin Case (May 25, 2010)

jez said:


> I've just mangled together 2 aluminum heatsink discs a little bigger than the diameter of a c cell and taped them tightly either side of the driver.
> 
> 
> With 4 c cells the current held for a little longer then dropped again but slower.
> The sinks got very hot too.



If you don't mind the mess, try adding a little thermal compound to the mounting tabs to put them in thermal contact with the aluminum disks. It's not the ideal way to heat sink those contacts, but it should give you rapid feedback in terms of effectiveness. If it works outright, you are all set. If you get longer run time but still suffer from early shut down, then you'll have to improve the thermal link to the aluminum disks, perhaps by fashioning some sort of metal standoffs that thermally connect the mounting tabs and the disks.

The mounting tabs are solderable, so you could solder a piece of large gauge wire to the tabs. You will need something that is a little more than 1mm thick/tall to rise above the top face of the AMC's case. 16 ga wire will do that. 18 or 20 ga plus some solder thickness could also work. Maybe even just a solo solder blob. Carefully file it flat for good contact to the aluminum disk and add some thermal compound.


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## vestureofblood (May 26, 2010)

jez said:


> I've just mangled together 2 aluminum heatsink discs a little bigger than the diameter of a c cell and taped them tightly either side of the driver.
> 
> 
> 
> ...


 

What you have there is not bad. If you have any arctic silver 5 or similar compound you could add just a tiny bit to the top of the driver components on each side. This would help transfer the heat to the sinks more rapidly. 

I am glad you have not gotten discouraged, you have all the making of a true flashaholic/moder IMHO. At this point I would say at the very least you have gained both knowledge and experience.


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## Mettee (May 26, 2010)

So what are we doing here, are we helping him(jez) to use 4 cells now or are we trying to get it to work as it should with the 3 cells. I got lost in all this tech talk and such. 

Jez, I think you are on the right track and that you have added some very robust additional enhancements that will help it run right. :thumbsup:

ETA: OH YEAH, and again, what is the output like JEZ? 

drew


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## ti-force (May 26, 2010)

Mettee said:


> So what are we doing here, are we helping him(jez) to use 4 cells now or are we trying to get it to work as it should with the 3 cells. I got lost in all this tech talk and such.



Personally, I think 3 NiMH cells would be the best option because of the 4 watts of waste heat that's created with 4 NiMH cells, but I guess it's really up to Jez. If Jez wants it to work with 3 NiMH cells, but can't get it to work, the only other battery options I see are 4 NiMH cells or 1 Lithium rechargeable.




Mettee said:


> ETA: OH YEAH, and again, what is the output like JEZ?



I'm not Jez, but I would imagine the output falls pretty darn fast after 15 or 20 seconds when 6 of the 8 7135's shut down.


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## jez (May 26, 2010)

Hi fella's,

I'm sorry this has all got confusing about what I want to do but with your help i'm progressing well.

Ideally I wanted 3 d's running the torch but had initial problems with low amps. I seemed to have reached a point where my cells provide 2.3A tailcap measured with pointy ended leads. Seeing as the driver is 2.5A not a bad outcome.

I had read that this driver can also put out 2.8A with replacement thicker gauge wire over standard but I misunderstood and thought this was again with 3 d cells. 
Hence a lot of my frustration.

Some advice from you guys got me trying 4 c's as I had these at home. 
Using these I got about 2.8A but this fell of rapidly to 0.7A so I thought this was a cell problem or a faulty board. 
Advice from you guys again got me burning my fingers which confirmed a theory that the board was cooking.
So out came some very ugly heat sinks just held on with tape and this slowed the current drop.

Tonight, out came the iron again and using Justin Case's suggestion I made some stand offs from 16awg wire soldered to the mounting tabs then filed flat to mate with the sinks. 
Using compound the torch held it's current for as long as I could hold the pointy ends of the dmm on the torch, can't believe the difference!
I've now cleaned this off and am in the process of waiting for the thermal epoxy to go off so I can give it a full run time test and let you all know the results.
Besides it can't hurt to have the driver heatsinked anyway can it.

As I mentioned earlier somewhere in the post (it's been that long) I've done a basic version of the spring resistance mod and I also ran a wire from the +ve spring tip through to the switch to improve that.

I had been cleaning the contacts as best as I could remember with IPA before soldering etc. I don't have any of the deoxit stuff.

Mettee, I'm sorry for missing you out. The output is fab at 2.3A but I seem to have got caught up in the 2.8A mission even though the driver is 2.5A - guess this is the start of something expensive 

I hope I answered everyones questions and I think I'm reaching a happy place to stop.

Now how do I get a tighter beam out of it 

Cheers

Jez


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## jez (May 26, 2010)

well it ran at 2.78A for about 7mins 30s then started to drop off seeming to hold around 2.1-2.4A ish after 14+mins but climbed back to 2.7 around 20mins.

couldn't tell you if it went back down again as my hands gave up holding the probes.

It seems to be a success, perhaps the dip was just a glitch?

Thanks very much for all your help, you really are a great bunch.

Now need some drain cleaner and a pair of snips for a tail spring mod

Jez

edit - carried on for 45+ mins still delivering 2.73A - torch makes a good handwarmer!
Vestureofblood - you're right, I'm really suprised what some 1/8" ali can do


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## Mettee (May 26, 2010)

right on! Ok so are you using 3 or 4 cells? 

Sounds like it is working properly if its 3 cells. It should get to a point that when its working right the current holds....seems like you are there.

for a tighter beam you can use the rebel led mag light reflector, I had great results with it.


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## jez (May 26, 2010)

Thanks for the info on the reflector Mettee.

I did the runtime check with 4 cells. I'm now tempted to run it with 4 just because I can now 

But it's good to know that I can use the d cells if I need to at 2.3A

Question - If I mod the tailcap spring for 4 c cells will it be to short to swop to 3 d's if I need to?


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## vestureofblood (May 26, 2010)

Excellent work jez. 

I am so glad you persevered on this. I wouldn't worry about that little drop in current, in real world use it wouldnd be that noticable.

As for the 4C tail cap. If I remember right the spring mod in a 3D to 4C makes the spring sit below the rim of the tailcap, so you probly couldn't just put the Ds back in. A couple of options would be to get a second Mag tail spring you could just snap in without even removing the other when you want to use the D cells. Or you could make a spacer out of some copper or aluminum.


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## TorchBoy (May 26, 2010)

jez said:


> edit - carried on for 45+ mins still delivering 2.73A - torch makes a good handwarmer!


That sounds quite good. If you do the same thing with 3 D cells what is the current after that much time?


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## jez (May 27, 2010)

Torch boy, i'll take the torch home and try it when I have time.


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## jez (Jun 1, 2010)

Did the short (45mins) runtime check with d's and was getting 2.1-2.3A steady.

Just for fun, put 4 c alks in and after just 5mins current dropped to 2A showing just how bad the voltage sag can be.
Put the 4c rechargables back in and 2.78A all the way 

Think i'm gonna run this in c cells and keep a spring for D's in an emergency.

Thanks again folks

Jez.


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## pugga (Jun 2, 2010)

Hi all,

I just received some drivers for a project and just checked on shinningbeams page but obviously they have sold out of them and have taken off the sales/specs page. Has/does anyone have the specs on the driver as I can't remember a few things for example here is the info from there XP-G/XR-E driver,

* Regulated circuit board designed for Cree XP-G and XR-E emitters
* 3 modes: Low>Med>High 
* Voltage input: 2.8V - 6V !!!!!
* The memory feature will memorize the last mode 
* Output current: 60mA on low, 440mA on medium and 1.4A on high !!!!!
* Buck circuit board !!!!!
* Linear regulators for high efficiency
* 17mm base board diameter
* Lead wires already soldered on board 
* Reverse-polarity protection prevents wrongly installed batteries from damaging the circuit

Thanks for any help

Cheers pugga


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## bstrickler (Jun 2, 2010)

pugga said:


> * Regulated circuit board designed for Cree MC-E and SSC P7 emitters
> * 3 modes: Low>Med>High
> * Voltage input: 2.8V - 6V !!!!!
> * The memory feature will memorize the last mode
> ...




Edited for you 

To lock the memory, light must be on for 3, 5, or 10 seconds, I can't remember which one it is.

~Brian


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## TorchBoy (Jun 2, 2010)

pugga said:


> * Buck circuit board !!!!!
> * Linear regulators for high efficiency


Neither of them is a buck driver !!!!! Both drivers are linear regulators.


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## vestureofblood (Jun 2, 2010)

TorchBoy said:


> Neither of them is a buck driver !!!!! Both drivers are linear regulators.


 

LOL!!!!!!!!!!!!!


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## ti-force (Jun 2, 2010)

bstrickler said:


> Edited for you
> 
> To lock the memory, light must be on for 3, 5, or 10 seconds, I can't remember which one it is.
> 
> ~Brian



Let me see if I can help you with your memory. Mode is memorized after the selected mode has been on for 3 seconds or longer, as long as Shiningbeam hasn't made any changes , and as long as my memory is serving me correctly.


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