My First DVD Laser Project

[Benm]

At 180 mA it should definitely be lasing properly, so i guess it died... but i wonder why really, your setup looks pretty solid to me.

Measuring with a multimeter is not really possible, electrically the difference between an (optically) dead laser diode and a functional one are very small. Usually some light still comes out and can be focussed, but the 'dot' is an odd shape (2 or 3 sort-of-dots with dark areas between them).

 

[paulham]

could it of been anything to do with the 6 mi-mh batterys i used?
they dont seem to output 1.2v more like 1.3v?

i just turned the pot on my other laser, down to about 120mA
so hopefully that one will live longer!

where can i get a better quality diode?
doe anyone else sell them apart from stonetek?

 

[Switch]

It should've been able to take it anyway...Maybe it has something to do with the infamous "bad batch". :-/

 

[chido]

Well, there's a group buy going on for the 200mW phazor diodes for 30 bucks each:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1202669249
If you want more power you can always order a Sony 20x dvd burner from newegg for 24 bucks shipped and harvest the open can diode, here's the thread:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1202158967/0
And here's a graph of the performance of the Pioneer diodes which apperently are the same as the Sony diodes:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1203149320

 

[Gazoo]

At this point since you have everything built and understand how it works, I would go for the beast... ;D Harvest an open can from a Sony drive and it will last you a good long while running it with ~420ma's.

That diode should not have died running with 180ma's. As much as I like Greg, I don't think it's a good idea to order diodes from him until he gets these diode problems resolved.

 

[chido]

All right paul, I got your pm, this is what an open can diode looks like:

 

[Benm]

could it of been anything to do with the 6 mi-mh batterys i used?
they dont seem to output 1.2v more like 1.3v?

No worries there, the regulator will fix any input voltage you present to it, up to as high as 30 volts or so. I will overheat and automatically shutdown after a while with too much voltage, but no permanent damage to regulator or diode should result from that.

 

[cyclonite]

Benm:

are you implying that the LM317 shuts down automatically when temperature goes up past a certain threshold?

thanks.

btw, does anyone want those pots or the LM317 but can't get them? PM me, I might be able to help you get some.

Cheers.

 

[cyclonite]

paulham:

If you still wanna test your diode.... since you mentioned Maplin I gather that you're in the UK. Depending on where we are, we could meet up and you could hook your diode up to my driver if you want... I've got a driver working perfectly well with the earlier good batch GB diode. I'm driving mine at 240mA but I don't leave them on for more than 15seconds.

I see from your HP DMM that you're driving it at under 200mA. How long did you leave them constantly on for?

Cheers.