C6 power problem, power dropping..

[i73770k]

So as the title says, i'm building a laser in a C6 host..
Not sure what the diode is it may be an M140 or A140, but i don't think that maters, got it from a member on the forum and it was already pressed in a module, he also did not know what it was.. That's why i'm running the diode at 1.25A..
I'm also using a 1.25A Buck driver from survival laser.
And for batteries i'm use two IMR 16340's

So the problem is that when i turn the laser on, its bright for around 500ms then it get dim, like super dim i would say sub 100mw, so very dim..
I don't think its the batteries because i tested them, and they are at 4.2v, also i got them off of Livinloud a week ago..
Also just having the pill in the host i tested the driver with my test load and i got 1.25A..
And for the diode, i just had it tested by a friend on the forum and he told me it was fine..
The diode also looks fine for the 500ms its bright..


What is my problem??:wtf:


:beer:
Rich

 

[i73770k]

Bump..

 

[crazyspaz]

Welll, its certainly not a diode problem, so thats good at least. My guess is driver problem, but im certainly no expert- however, and thankfully so, there are plenty of experts here

 

[i73770k]

Update..

Its not the batteries. I tested the driver and diode with a power supply set to 8.4v, i got the same result of the power just dropping..
Next i desolderd the driver from the diode, and hooked it back up to my 3A test load, and i got 1.25A?!?!?!?!? Then i hooked it back up, and i got the same power dropping affect...

:wtf:

Not sure what to do:yabbem:

 

[Pi R Squared]

Do you have an 18650 battery? If you do then take out those 16340's and put in the one 18650 and see if you get the same result.

 

[IsaacT]

It sounds like your driver circuit is overheating. This creates resistance I think? Causing the current to drop. I had a similar issue with a 532nm module I had once. Try heatsinking the driver.

 

[Pi R Squared]

Is this the driver? Survival Laser Driver
If so then it is very efficient and should never overheat or require heat sinking.

 

[i73770k]

Is this the driver? Survival Laser Driver
If so then it is very efficient and should never overheat or require heat sinking.

Yep that's the driver i got..

With an 18650 i get the same dropping affect, just not as bright when it first turns on..

Also i was noticing that when the laser sits for a long time, and when i turn it on it will stay bright for around 2.5 seconds, then goes dim.. Then after that first 2.5s, every time i turn it on after that it will only be bright for around 500ms..
So maybe its a heat problem??

Should i just ask for a new driver??

 

[paul1598419]

I had this same problem a while back with an M140 laser diode. It turned out to be the diode. No kidding. I was driving it with lazeerer's 1.8 amp V6 X-Drive and the laser would be fine for a short while, then it looked like it's laser cavity got destroyed and it turned into an LED. It finally went to LED "mode" all the time, and that's when I replaced the diode. Problem resolved.

P.S. Also, since this is a buck driver, you can't just substitute an 18650 for two 16340s because your input voltage will be too low to drive the diode.

 

[i73770k]

Just tested the amps going form the driver to the diode.. It was a steady 1.25A I guess that means it's the diode.

P,S, Thank you all, for helping me diagnose the problem.
I only wish the outcome would of resulted in a bad driver, and not a diode..

 

[paul1598419]

i73770k, sorry to hear that, but I'm not surprised. It really sucks when you lose a $45.00 diode in such a short time of use.