Blue laser malfuntioning

[borgqueenx]

For some reason my blue laser malfunctions.
During the installation of my green laser, the 6v power supply for the blue laser died because i snapped a cable from it and soldering a new one on it has failed.
So ive got my new power supply today. Tested it and gives 6,19volts to the flexmod p3.
The flexmod p3 is connected to the casio diode.(no idea what diode but can give 2w if overdriven.

The weird part is that the diode goes immediatly on after turning on the projector...i was used to having a 5(or so) second delay. But inspecing closely i see a very small increase in brightness after a delay of about 5 seconds.
And after commaning the projector to give full 5 volts, the laser doesnt give alot more power. I see it go up in brightness but its like 2mw or so. The red error light of the flexmod does not lid. It stays off.

I do not understand why this happened. It worked well with the new power supply first. Then i needed to put the module a bit higher so i unscrewed the whole module to make it higher. After making it higher i screwed back the module, connected back the wires. It went on but then suddenly off.
I have no idea what went wrong. I checked connections, all wires are properly connected.

Some help would be great!

Edit: turning the knob of standby power still helps! I can control brightness with it from zero power to like maybe 1mw.

But output power with full 5v has no effect. Also when measuring voltage with full 5v signal at the socket connecter wich is directly connected to the diode...i only read 4,2v. I think ive read somewhere that the diode only works on 5,5v?

So what do you guys think...? The diode blew? The adapter does feed 2.5a max instead of 2a.
But i didnt chance the knob for current.

[laserwinkel]

2-2,5 A on the diode seems to be overdriven too much in my eyes.
i keep blue diodes on 1A and a max of 1,25A (old casio XJ-A140 diodes)
2,5A might blow the diode.

another reason could be ESD on the resoldering of the diode wires

but i do not have much experience with the P3 so could be another reason inside the driver

[borgqueenx]

I dont think it got 2.5a but im not sure. I cant measure current for some reason.
I didnt chance the knob on the driver so why would it then jump from 2a to 2.5a? If it was already set at 2a...it got me 1,6w after optics on the 2a power supply but screwed it back to 1,3w.

I also find it weird that between the flexmod p3 driver and diode, i read 4,2v when full signal is applied...
I thought it needed at least 5,5v?

Is there a way to find out if the power supply driver or diode has gone bad?
The power supply is really stable at 6,19v.

Edit: what is esd and how do i check if thats the error and/or fix?

[DTR]

The diode is a M140 as you got it from me a few months ago. 2A is way too much current. I would suggest staying under 1.6A for continuous use with proper heatsinking.

With the forward voltage of a 445 you should be able to stay in regulation on the P3 @ 1.6A to the diode with as little as 5.5V.


Are you sure you are giving the unit 6V? Also are you using a common ground for the mod input or no?

Some pictures of your setup could help.

You may need to put the P3 on a test load to check that it is working correctly with the correct load and if it is then test the diode.

[borgqueenx]

Probaly gave it too much current then. A diode dies by suddenly "snap- power goes to 1mw in a blink of an eye"?
I dont know what common ground is. The white wire out of the diode is hanging loose with tape on it so it doesnt contact anything.
Pictures:
http://d.pr/i/3dF0
http://d.pr/i/bvzT

[drlava]

Ok, I'll try to sort through this..

For some reason my blue laser malfunctions.
During the installation of my green laser, the 6v power supply for the blue laser died because i snapped a cable from it and soldering a new one on it has failed.
So ive got my new power supply today. Tested it and gives 6,19volts to the flexmod p3.
The flexmod p3 is connected to the casio diode.(no idea what diode but can give 2w if overdriven.

The weird part is that the diode goes immediatly on after turning on the projector...i was used to having a 5(or so) second delay. But inspecing closely i see a very small increase in brightness after a delay of about 5 seconds.
And after commaning the projector to give full 5 volts, the laser doesnt give alot more power. I see it go up in brightness but its like 2mw or so. The red error light of the flexmod does not lid. It stays off.

6V PSU is a good choice for the 445nm diode, but 2W is too much for them to last. It's not clear from your posts at what level of current you set the driver output to, but from your description (2mW at full current) the diode has suffered output facet failure, possibly from being over-driven.

I do not understand why this happened. It worked well with the new power supply first. Then i needed to put the module a bit higher so i unscrewed the whole module to make it higher. After making it higher i screwed back the module, connected back the wires. It went on but then suddenly off.
I have no idea what went wrong. I checked connections, all wires are properly connected.

Diode failure after mechanical manipulation may be coincidence, or: High-power back reflection in new position, disconnection of diode from protective circuitry during movement and ESD (electrostatic discharge), degradation of cooling, diode pin twisting and bond wire breakage (not the case here), mechanically-induced electrical shorts causing faults to driver circuitry (the driver bottom may have touched your base plate or bolt, etc while on, creating an electrical fault).

But output power with full 5v has no effect. Also when measuring voltage with full 5v signal at the socket connecter wich is directly connected to the diode...i only read 4,2v. I think ive read somewhere that the diode only works on 5,5v?

The 445nm diodes do have a forward voltage of about 4.2V. This is normal. It's the driver that needs some headroom above this (5.5V+) to operate nominally.

So what do you guys think...? The diode blew? The adapter does feed 2.5a max instead of 2a.
But i didnt chance the knob for current.

The diode blew, yes. The current rating on the adapter seems adequate, if that's what you mean by 'does feed'. If you mean you measured the current output and it's delivering 2.5A, then clearly this is the reason for diode failure: overdriving.

I dont think it got 2.5a but im not sure. I cant measure current for some reason.

Check the internal fuses of your multimeter, you've probably blown at least one.

The driver quiescent current is fairly low, under 100mA so if you're measuring 2.5A on the output of the PSU then it's probably getting at least 2.4A, as long as there are no circuit faults in your setup. However, again, if the PSU is just RATED for 2.5A, this line of discussion is of little use.

Is there a way to find out if the power supply driver or diode has gone bad?
The power supply is really stable at 6,19v.

Edit: what is esd and how do i check if thats the error and/or fix?

The diode is bad, little doubt of that. You can test the driver with your multimeter in current mode once you've fixed your multimeter. You can also use a dummy load and use the multimeter volts mode across a current sensing resistor. Once you've confirmed operation of the driver, you can safely (or someone can) replace your diode.

Probaly gave it too much current then. A diode dies by suddenly "snap- power goes to 1mw in a blink of an eye"?
I dont know what common ground is.

Probably, yes. Yes, this is the way a diode dies.
Common ground refers to the concept of having multiple elements of a circuit share a common reference for measuring voltages, where the reference is grounded. Most projectors use a common ground system.

The white wire out of the diode is hanging loose with tape on it so it doesnt contact anything.

This is a bad idea. Floating diode pins are a perfect pickup for ESD.

[borgqueenx]

Thanks andrew!
Il try to fix the dmm or use another one.

The power supply is indeed rated for 2.5 a. I dont think it actually delivered that.
Is it better to cut the wire then?