# Green Laser Power Supply



## fedcas (Aug 3, 2006)

Hi,
I have a 5mW green laser pointer but I have broken it while trying a modification. Now I have unmounted it and I dissolded the diode from the circuit board. The diode has 3 pins, is there a way to check if the fault is in the circuit board and the diode is still working?

I have looked for schematics with google and I found 3 circuit layouts: http://www.walshcomptech.com/repairfaq/sam/laserdps.htm#dpsglp1

here you are the schematics:



















The question is: if I have understood correctly, according to the schematics the laser diode has 2 pins only, and mine has 3... why? how should I coonect it?

Thanks


----------



## jkaiser3000 (Aug 3, 2006)

laser diodes all haver three pins, but most of the times for our purposes only two are used. The third pin is for the photodiode, which is often not used or present.

As for which is which, I'm currently not sure. I believe in this case pin 1 would be positive, and pin 2 negative (pin 2 is the one shorted to the case). But someone with better knowledge can say this for sure :huh2:


----------



## N8YWF (Aug 3, 2006)

Wouldn't pin 2 be hot since the case is hot? Unless his batteries load up like a flashlight.


----------



## fedcas (Aug 4, 2006)

ahh I see... thx 

in addiction do you know if there is a way to test my green laser diode and check if it is still working?

I have also tried to give some current to the diode and I have been able to see a fleeble and very little red light inside the diode. Does this signify anything? I know that inside green DPSS laser there is a red led...


----------



## ted_park (Aug 4, 2006)

fedcas said:


> ahh I see... thx
> 
> in addiction do you know if there is a way to test my green laser diode and check if it is still working?
> 
> I have also tried to give some current to the diode and I have been able to see a fleeble and very little red light inside the diode. Does this signify anything? I know that inside green DPSS laser there is a red led...



Danger, Will Robinson. The light from the pump is 808nm, which is barely visible but can easily cause blindness. Don't ever look at the light from the pump, use goggles, and if you need to see what's going on, a web cam modified to see IR.


----------



## stihl88 (Aug 4, 2006)

Do not look at the diode while testing it! even if you looked at it in a mirror it will still get you... The light is barely visible, 808nm is Infra Red light which is very harmful to the human eye. The light is present but we can only just see 808nm.

You wouldn't stare at your 10mw Green laser would you? So don't stare at the Diode that's in it! The diode that's in it may be rated between 300mw and 500mw also.


----------

