Test 445 ld

[hivelaser]

I had a really bad night I think I killed 4 445nm LD, they been working fine on a 5v psu, but I changed over to a 12v supply and lowered it to 10.6v then I adjusted the current for the flexmod 3, hooked them up and they started lasing after a short time when I applied the 5v they got bright for a moment and went dark... I was at about 800mA. That happened to all of them. I really don't know what happened.

Is their a way to test the diodes without a driver just to see if they still work? Any help on this matter would-be great. I have everything here regulated psu,fluke, just no scope. I really hope they still working.

[dilbert]

I'm guessing you had them wired in parallel if running off 5V. So 800ma was split amongst the 4 diodes???? I'd expect 800ma each.

Most likely you blew the fet on the flexmod as it had a greater dissipation with the higher voltage. How had you heatsinked it?

I think your LD's are probably OK & would try another driver.

[hivelaser]

Yes correct I had them in parallel with laser bugs and laserorbs on each of the diodes also had the resistor on the laser bug that was supplied. Do you recommend an other driver just for a test setup doesn't have to be analog just for Cw testing I guess.

Also I need a new driver then for analog setup any recommendations. I think I want to drive 2 diodes at the same time with each at about 900 to 1000mA.

[Solarfire]

Yes correct I had them in parallel with laser bugs and laserorbs on each of the diodes also had the resistor on the laser bug that was supplied. Do you recommend an other driver just for a test setup doesn't have to be analog just for Cw testing I guess.

Also I need a new driver then for analog setup any recommendations. I think I want to drive 2 diodes at the same time with each at about 900 to 1000mA.

If you have a PSU with separetly adjustable voltage and current do the following:
With current set at full set the voltage to 4,7V,
Turn down the current to 0A.
Short the + and - terminals of the PSU.
Connect the diode and then remove the short on the PSU terminals and slowly increase the current while monitoring the current level.

To shut down:
Turn the current down to 0A.
Short the PSU terminals.
Turn of the PSU and remove the diode.

cheers!

[hivelaser]

OK i tested all 4 diodes, with PSU set to 4.7V and Current to 0 then increased it to 0.25A but nothing happened, so i guess they are all dead... bummer. Anyone know where i can get some new LDs as well as a new driver i think that one is shot too.

Someone in Cali or US i would like to send out the diodes, maybe someone else can test them for me.

[allthatwhichis]

If you have a PSU with separetly adjustable voltage and current do the following:
With current set at full set the voltage to 4,7V,
Turn down the current to 0A.
Short the + and - terminals of the PSU.
Connect the diode and then remove the short on the PSU terminals and slowly increase the current while monitoring the current level.

To shut down:
Turn the current down to 0A.
Short the PSU terminals.
Turn of the PSU and remove the diode.

cheers!

Is this really a valid way to test diode? I ask due to ignorance; it seems a bit unsafe to me, but again, I am ignorant.

[Solarfire]

Is this really a valid way to test diode? I ask due to ignorance; it seems a bit unsafe to me, but again, I am ignorant.

Unless you have a real shitty PSU or one out of the 1950s (with scratchy pots) then I would say yes. I Tested the 3 PSUs I have here and even my low cost passed using the above described procedure, no I/U spikes could be measured. Since then I have tested 1000s of diodes this way even the sensitive LOCs and diverse C-Mounts.

Cheers!

[DTR]

OK i tested all 4 diodes, with PSU set to 4.7V and Current to 0 then increased it to 0.25A but nothing happened, so i guess they are all dead... bummer. Anyone know where i can get some new LDs as well as a new driver i think that one is shot too.

Someone in Cali or US i would like to send out the diodes, maybe someone else can test them for me.

If you wanted to send them out to me I could test them for you.

Is this really a valid way to test diode? I ask due to ignorance; it seems a bit unsafe to me, but again, I am ignorant.

I have had great success with Mastech HY1505D which is a $80 PSU. I have tested hundreds of didoes on it and will say if you do it correctly you should never loose a diodes. I did loose a couple that I was torture testing back when we first started playing with these diodes. As Solarfire said make sure you have it set to about 4.7V(which will give you the full range of current) and the current turned all the way down(this will help prevent current spiks on startup), turn it off, short the leads on the power supply, hook it up to your diode, turn it on and slowly turn the current up. Also another trick is if you are just checking that the diode is functional set it to say 4.2V and even if you turn the dial on the current all the way up it will only go to about 1A.

[hivelaser]

Thats the one i have, should be OK, right?

Extech 382260 80 Watt Switching Mode DC Power Supply - link here

[DTR]

Thats the one i have, should be OK, right?

Extech 382260 80 Watt Switching Mode DC Power Supply - link here

You should be just fine with that one. It actually looks a lot nicer than mine. But I was really wanting one that can handle up to 5A and I saw a few people saying this one was very inexpensive and worked great. It is bare bones though. Does not even have a backlight on the LCD.

Here is the one I have.
http://shop.ebay.com/i.html?_nkw=MAS....c0.m270.l1313