FM3 Issues

[wondertwnz]

Anyone else having bad luck with the FM3. I have had 3 of them die in the last month or so.
I have come to learn that I am dissipating more heat than some would prefer, I am driving either two or Three 445nm diodes in parallel from 12V supplies.
However I have them mounted to VERY large head sink (the whole bottom of the projector)

Two of them have died when I remove them and try to reset the current (Adding or subtracting a diode)

Just wondering if anyone else is having bad luck also if they can be repaired ?

Also wanted to see if they are still readily shipping ?
Larry

[slicklasers]

Hi Larry,

I have had soooo many pop on me it's not even funny... probably over 15 or so.... What I have come to find is that they don't like to drive more than 2 diodes...

[flecom]

I have had two die on me, not sure what the cause of death was... when I was messing with the current on one some part let out the magic smoke... and then another was working fine driving 2x 445 diodes when it went up in smoke also... was running off of 12vdc

[dilbert]

If you are running off that high a voltage you are much better with them wired in series than parallel for so many reasons to reduce the power dissipation in the FET. For example 2 x 445's @ 1A in parallel @ 12V is approx 15.4W in FET, 2 x 445's @ 1A in series is only 3.4W so 4 or 5 times worse..............

[wondertwnz]

So , sounds like other have had the same problems. At least now I am pretty sure it was nothing I did.
Has anyone heard anything from Dr Lava on these problems? Or heard from him at all, Are they still shipping?

[Doc]

If you are running off that high a voltage you are much better with them wired in series than parallel for so many reasons to reduce the power dissipation in the FET. For example 2 x 445's @ 1A in parallel @ 12V is approx 15.4W in FET, 2 x 445's @ 1A in series is only 3.4W so 4 or 5 times worse..............

^^^ This is the answer ^^^

Either run your 445s in series or use 5.5 - 6.0 volts

[flecom]

ya mine were in series

[Doc]

Hmm, perhaps the good Dr needs to answer this one after all.