HeNe Laser Power Supply Components

[teroenza]

I recently salvaged a Melles-Griot HeNe laser from an FTIR system. I neglected to save any of the electronics except for what I think is the step-up transformer attached to the laser tube. The laser is "05-LSC-708-540" and the transformer is "05-LPM-850-045".

I have a 12V power supply, but was wondering I need to also come up with additional control electronics, like a current controller, to get the laser to work. There are only two wires going to the transformer (+12V and ground).

I see at the link below, that I should get a fuse in case things go wrong.

http://www.repairfaq.org/sam/laserhsc.htm#hscmg1

 

[davenn]

There are only two wires going to the transformer (+12V and ground).

since transformers don't operate with DC voltage, There will be more components needed ...
an oscillator to convert the 12V DC to AC to feed to the transformer
The red and black HV+ and - leads out the right side will be most likely in the order of 500 - 1500V DC
check the datasheet spec's for the tube for a more accurate voltage recommendation
There will be AC off the secondary of the transformer that, most likely, is rectified by one or more diodes
to produce the HV DC for the tube

do some googling for the tubes datasheet, It may even have a recommended power supply schematic included

Dave

 

[teroenza]

Sorry, should have mentioned that the foil-wrapped brick attache to the tube also has "Input:12VDC WMAX:9 Hz:N/A Output: 1.10-1.50KVDC 4.5mA" written on it, so it likely has the oscillator and rectifier built in. The beefy wires that I assume are the HV leads are affixed already to the laser tube.

It does have a small purple wire labeled CDRH that is looped back on itself. From here: http://www.repairfaq.org/sam/laserhps.htm#hpsrtc0

I think that that purple wire is a turn-on delay.

 

[jim hardy]

How familiar are you with laser safety ?

That's a 5mw laser so check local regulations to be sure you can legally own one,
and never point it skyward because you don't know where the airplanes are.. it's a big deal to pilots when a laser beam comes through the windshield.

Sorry if you're an old hand. but you didn't say.

 

[teroenza]

I'm a physics graduate student in a lab that routinely uses 18W IR lasers, and I bought some cheap ~633nm laser goggles. I know of no regulations prohibiting such a low power laser in my area. I am more unfamiliar with the HV part of the supply, but with the leads going right into the tube, I don't plan on messing with that part.