Green Laser Diode/Driver problem

[obnauticus]

Hey!

I just picked up an American DJ Emerald Scan for $40 at a local thrift store. All the robotics work which is very nice. The problem I am having though is either the driver board or the diode is broken. When the driver board from the original device is driving the green 4.9mW laser diode it lases a very faint red. What would cause a green laser to lase at this wavelength and intensity?

When I plug an external power supply into the diode, it lases green at 2.0VDC at around 300-400mA. With that in mind I am thinking this is more of a problem to do with the driving circuitry in my new device.

If I need to replace the driver/diode, what do you guys think I should throw in there? Keep in mind the application of the device...I dont want to burn people's retina's out while dancing with a 500mW laser lol.

In the event that someone else finds these handy, attached are pictures of the internal design. It is very modular which is nice.



and



Here is a full PDF manual for the device: http://www.blacklight.com/files/ADJEMERALDSCAN.pdf

Thanks in advance!
obnauticus

 

[photonaholic]

That's a nice little unit, sounds like the power supply has the problem, if your module lases with a different power source, then it stands to reason that the internal power source has a problem.

Good luck.

And Welcome to the forum.

 

[obnauticus]

That's a nice little unit, sounds like the power supply has the problem, if your module lases with a different power source, then it stands to reason that the internal power source has a problem.

Good luck.

And Welcome to the forum.

The voltage of the driver that is inside of it right now is calibrated to like 2.169V-2.2V (I am not sure if this is correct because it could have been modified or changed over time/etc.). I am not sure about the current. What Voltage/Current should I be looking for?

 

[Hemlock_Mike]

Does the internal PS provide 2.0 Volts? As said above, You have answered your own question. It appears to be a problem with the internal power supply/driver.
As you state above -- 2 Volts at ~300 mA depending on the power you want and the ability of the device to provide heatsinking.
300 Ma may be high for that "toy".
HMike

 

[obnauticus]

Does the internal PS provide 2.0 Volts? As said above, You have answered your own question. It appears to be a problem with the internal power supply/driver.
As you state above -- 2 Volts at ~300 mA depending on the power you want and the ability of the device to provide heatsinking.
300 Ma may be high for that "toy".
HMike

The leads that go to the diode from the driver board measure about 2.1-2.2V. I am still not sure about the current. Maybe I should hook my scope up to it to see what is going on.

 

[obnauticus]

When I hooked the Positive and negative leads of the driver into my scope I saw the following image (the top one is +, and the bottome one is -, because of the refresh rate of my camera, the lines look like they are going stright through the pulse cycles, but they dont in the actual graph). The duity cycle pulse is to control the dot size, and it reacts in height and width to bass.




Here is a video:

http://yfrog.us/1svid00014201002211728z

This video is better, you can see the pulse width and duity cycle of the pulse changing as I blow into the device's embedded microphone. I still do not understand why there is an AC looking waveform going into this diode.

http://yfrog.us/09vid00015201002211734z