Selecting the proper diode..

[TheeReverendObsk]

Hey folks,

I've been busily searching this site for the past few hours, trying to gather enough of the right information to make an informed decision, and while I've found a great wealth of information, I was wondering if I could be more efficient in my gathering of it.

So I elected to post this.

All other considerations regarding properly regulated power and efficient heat dissipation being equal, what would the best 405nm diode be for an application with the following requirments?

-Continuous use (hours at a time, at least).
-Power output of 100-120mW.

We've been experimenting with the PHR violet ones, and have successfully killed 4 of them so far, more due to our ignorance regarding certain key differentiators of these diodes from the more common red ones.

Live and learn.

Anyway, any help is greatly appreciated, and I'll keep looking myself in the meantime.

-TheeObskure

 

[daguin]

At 100mW your PHR should run 24/7 for months.

Peace,
dave

 

[TheeReverendObsk]

Wonderful, I was hoping this would be the case, as everything I'd come across thus far had pointed to that being the case.

After getting everything setup properly, my next step will be investigating PWM control for these things, does anybody have any suggestions as to where I should start looking for that sort of thing?

Thanks!

 

[kristopher]

I agree with Dave, they should run a long time.  Make sure you have adequate heat sinking.

As for your second question, I found several schematics over at Sam's FAQ (here http://www.repairfaq.org/sam/laserdps.htm#dpssg1 ). Some have an external photodiode for feedback. Was that your question?

 

[pseudolobster]

PHR-803t diodes do not have an internal photodiode and I'm not sure how you'd set up an external one in the beampath without a whole lot of work... Why PWM anyway? Most people around here just drive these CW, so we focus mostly on simple constant current drivers... What are you thinking of trying?