I Killed My Diode But Not Sure How

Well the title sums it up. I recently built a laser with an M140 diode in a stainless C6 host with a g-2 lens. I used the fixed current SL driver @ 1.8 amps. I also purchased a battery tube extension so I could run it on 2 18650's. The batteries I used are circuit protected 2900 mAh Orbtronic 18650's. That sums up the build so now for a short story.

I liked using a single 18650 in the build so I could have about 200-300mw (estimated) instead of 2 watts (again estimated by previous builds similar to mine). I finished my build Monday and everything worked for the past 2 days. I used a duty cycle of 1 minute on 1 off (I almost never actually ran it near a minute with it at 2 watts). With the single 18650 the host wouldn't get warm with the extended copper heatsink from SL so if I wanted to run it longer than a minute I would run it like that.

Earlier today I wanted to use it with the 2 watts and put in the 2nd 18650 with the extended tube but when I turned on the laser the output was extremely low (less than that of the single 18650 output) so I turned it off fearing I fried my diode. I charged my batteries and tried again but still extremely low output. Before I put in the 2nd 18650 about 30 minutes before the diode was doing fine with the single 18650.

So my question is any ideas on how this happened? I want to order another diode from DTR but I don't want to install it and fry it again without knowing what I did wrong the first time. (Also I can't really afford to burn through diodes since I'm a poor college student )

Here are my solder connections. After I removed the heatshrink tubing.


Here is my driver from SL that I soldered in. The left connection appears to have more solder than it really does in the picture and the solder does not overflow.


Thanks for any input on what I could have done wrong. -HAM

Just a quick question: shouldn't those two wires be insulated at the joins?

RB astro said:

Just a quick question: shouldn't those two wires be insulated at the joins?

Click to expand...

Yes I said that I removed the heatshrink tubing after I killed it for the picture!
Well maybe it wasn't super clear but it is above the picture. -HAM

Do you have a test load and a DMM? A test load isn't required if you buy only pre-set drivers but is still a good idea to have if you will be building more lasers. If you had both then you could unsolder the module and test the driver to be sure it's puting out approximately 1.8A.

Alan

Sending you a message.

With 2 3.7v batteries my driver is putting out about 1.8 amps....I received my new diode from DTR today installed it and everything is back to normal! I guess I received a bad diode or some other weird issue. Thanks for everyone's help! -HAM