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What could be causing this?! Input needed

jdzipf

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Here is a video of it running. Notice it's very bright for a fraction of a second then it dims significantly and sooner or later starts flashing.

445nm - YouTube

Running an M140 diode with huge heat sink
2 18650 4300mah batteries
Using a 1.7 amp driver with small heatsink on the regulator

All input greatly appreciated! I have found this forum to be my best resource for the hobby!
 





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The driver seems to be overheating.

What exactly are you using to drive the LD?
 

jdzipf

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I'm not sure what kind of driver it is, here is a photo.

null_zpsff0ee8ed.jpg



And also the driver board in the background is bypassed I'm only using it for positive and negative contacts from the battery. I wrap the main driver being used to push the LD in electric tape to prevent shorts.
 
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You should be able to use the main driver in place of the stock driver ??

Try a bigger heatsink on the driver if you can, sounds & looks like it's overheating
 
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If you don't use the stock driver, just make sure it is not drawing power from the batteries.
It may insert some noise into the VCC line that may enter the functional driver...

Oh well. Its hard to tell. I don't know what driver the stock one is. but if you are not going to use it, is a good bet to remove it or make sure it is non-functional (dummy).
 
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Greetings,

If you have not replaced the batteries, that is where I would start. That is exactly the behavior when there is a battery issue.

cheers,
Moe

Here is a video of it running. Notice it's very bright for a fraction of a second then it dims significantly and sooner or later starts flashing.

445nm - YouTube

Running an M140 diode with huge heat sink
2 18650 4300mah batteries
Using a 1.7 amp driver with small heatsink on the regulator

All input greatly appreciated! I have found this forum to be my best resource for the hobby!
 
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Apr 3, 2013
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where did you get that driver .. looks like a sort of multi mode thing with that strobe
ive also had batteries do strange things like that
 
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jdzipf

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I'm thinking its batteries too. Both measure 4.12 on meter but current is way different on each. Testing each by setting my meter on 20m for current test shows 6.8 for the first battery and 11.0 on the second. And that is after charging both of them.

One battery is named "Ultrofire" and one "Ultrafire" just to add. The "Ultro" is testing with the higher current.

The driver I purchased on eBay from US seller.
 
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The LD looks like a Mohgasm linear round driver... and it doesn't look like it's properly heatsunk.

And... you don't measure the current of the batteries, it will damage the meter and the battery.

The larger driver with more components, can you tell us where the wires are connected to?

The red wire should be connected to the + contact and the black should be connected to the - contact plate.
 
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jdzipf

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Here is some better pictures of the guts.

null_zps64169dc6.jpg

null_zps95213002.jpg

null_zps53899c24.jpg

null_zpsf24a312d.jpg


Hope this helps, otherwise I'm going to start by picking up new batteries today.

Also I wanna say thanks for all your help and replying! =-)
 
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Ah, that huge chunk of aluminum should be enough to keep the driver cooled.

I think the wiring on the battery contacts to the driver leads are good as well.

Perhaps the components from the original flashlight driver are interfering?

The next culprit would be the batteries, as they hardly can handle the 1.6A load.
 
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Ok, first I would test the LD with driver without the stock driver. If both drivers are the same size take the spring off the original and solder it on the LD driver.
 
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jdzipf

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I had it running with the stock driver removed and spring on the LD driver, but I had the same exact dimming results. I do not believe the stock driver is causing this. I've removed several chips from it and soldered on the LD driver to it carefully to where it wouldn't mess with my circuit. I also had tried this same LD on a single mode driver with the SAME batteries and it dimmed but did not start flashing.
 
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So firstly, you never want to drive a driver with another driver. You could not drive the LD correctly and or ruin both drivers. You removed a couple components from the driver you are using as your contact plate but you did not remove all which I would have advised and that could cause problems. Though since you say you are unable to achieve full power with a different driver setup likely this issue is unrelated to the drivers.

I would think the issue is likely your power source. First off never test a lithium cell's discharge capabilities directly on a multimeter. The current they output at a full short is massively damaging to them. Also, exactly what cells are they? To my knowledge the only cells with anywhere near that kind of rated capacity are 26650s, 32650s, and Panasonic 18650s and I don't think Ultrafire makes any cells larger than 18650 so the ratings are likely all fake. Your problem is most likely that the voltage of your cells are sagging too heavily to properly supply the driver and power the diode. You should look into better grade cells for sure.
 
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Greetings,

Ultrafire does make 26650's and they are garbage just like their other sizes. I had one die last night. Checking voltage it shows less then 1vdc. A good battery will normally show somewhere from 3.5vdc to about 4.2vdc, discharged and charged respectfully, for that type.
As you recommend, I would use better quality batteries.

cheers,
Moe

So firstly, you never want to drive a driver with another driver. You could not drive the LD correctly and or ruin both drivers. You removed a couple components from the driver you are using as your contact plate but you did not remove all which I would have advised and that could cause problems. Though since you say you are unable to achieve full power with a different driver setup likely this issue is unrelated to the drivers.

I would think the issue is likely your power source. First off never test a lithium cell's discharge capabilities directly on a multimeter. The current they output at a full short is massively damaging to them. Also, exactly what cells are they? To my knowledge the only cells with anywhere near that kind of rated capacity are 26650s, 32650s, and Panasonic 18650s and I don't think Ultrafire makes any cells larger than 18650 so the ratings are likely all fake. Your problem is most likely that the voltage of your cells are sagging too heavily to properly supply the driver and power the diode. You should look into better grade cells for sure.
 




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