help with a build problem

[ultimatekaiser]

Ok, so I built the laser module such as I always do. contact board to driver to diode, etc, everything is solid and i connect batteries, it works. everyones happy. but then I go to put the module in the heat sink....bam the diode goes out, i take it out of the heatsink, it lights back up. the heatsink must be acting as a short. any ideas?

my guess is that the diode uses the case as part of the circuit (+)

 

[ARG]

Check the continuity between all the points in the circuit, driver in + and - and driver out + and -.

You're likely right about the short, or it may not be making the circuit connection inside the host. Either way a continuity test will tell you a lot of what the problem is or isn't.

 

[ultimatekaiser]

well the way i see it i dodged a bullet. the diode must be case positive. which is sending the positive straight back to the battery through the heatsink instead of through the diode. (had i wired the contact board the other way it would short out the diode ) guess maybe i need to isolate the module from the heatsink somehow? or maybe my line of thinking is wrong?

 

[jander6442]

So what diode are you using.

 

[cheech226]

and what driver? maybe one that's continuos positive?

 

[jander6442]

Cheech is on to it, sounds like your using a case negative diode with a non continuous driver.

 

[ultimatekaiser]

Hmmm. It's a Lm1117. Was the only thing I could dind that had the necessary voltage drop

 

[cheech226]

what diode?

 

[ultimatekaiser]

its a circulaser diode, and its old, so no idea of its properties case wise. I had assumed it was case neutral. It's a PS031-00 @ 680nm.