CT Galvos? ID required please

[Galvonaut]

Has anyone ever come across these galvos? I think there used to be barely visible CT sticker on one which seems to have escaped into the ether.

The mirrors seem pretty hefty, so I can't imagine them being very fast but any info would be greatly appreciated.

The date on the PSU board is 1983.

[Photonbeam]

General Scanning G100PD or G120PD with LaserMedia amp. You can get 24K speed from them and they will sling big mirrors. They were the standard before CTI.

[mixedgas]

The green board pictured is an LM SDA-22 AMP. I may still have the schematics/manual but that is a 12 to 14 Kpps AMP at small angles. I've used a few in my time. The G120s will do 24K with a faster amp.

Before using, there is a procedure for setting the DC offset of the Galvo Amp, I would strongly suggest doing that on both the X and Y channels before using the amplifier. It is a simple procedure involving a voltmeter, with the input grounded, while watching the dual color led on the board. I'm leaving for SELEM, so it may take me a while to post it.

Steve

[Galvonaut]

Thanks Photonbeam and Steve.

That's great info and I guess it's worth keeping them for a future project.

Info on setting the DC offset would be great. Thank you. Have a great time at SELEM!

Keith

[Galvonaut]

I suppose I should bump this thread and request the schematics and manual from Steve. I'm enquiring about a laser workshop/hackspace at the moment and may actually get around to doing some building!

Not sure what to do with this scan set but may as well get 'em up and running.

Keith

The green board pictured is an LM SDA-22 AMP. I may still have the schematics/manual but that is a 12 to 14 Kpps AMP at small angles. I've used a few in my time. The G120s will do 24K with a faster amp.

Before using, there is a procedure for setting the DC offset of the Galvo Amp, I would strongly suggest doing that on both the X and Y channels before using the amplifier. It is a simple procedure involving a voltmeter, with the input grounded, while watching the dual color led on the board. I'm leaving for SELEM, so it may take me a while to post it.

Steve

[Pangolin]

These are actually terrible amps! They force the position sensor to work single-ended (something it's not intended to do) and so these amps will eventually blow the position sensor diodes inside the scanner (diodes which are sealed with epoxy, thus, rendering the scanner useless). And yes, these amps to 12K, nothing more... 12K was the standard scanner speed for G-120s. Only Turbo Track and a few others got G-120 to go faster...

Bill

[Laser Wizardry]

" 15 characters"

[Galvonaut]

Thank you Bill. I might save these for a rainy day project then. Some better amps may turn up on ebay if I'm lucky.

These are actually terrible amps! They force the position sensor to work single-ended (something it's not intended to do) and so these amps will eventually blow the position sensor diodes inside the scanner (diodes which are sealed with epoxy, thus, rendering the scanner useless). And yes, these amps to 12K, nothing more... 12K was the standard scanner speed for G-120s. Only Turbo Track and a few others got G-120 to go faster...

Bill

[swamidog]

yeah.. i was going to suggest some accel 124's. they'll be a lot easier to find than turbotracks. i have some here, if you want to come over and try your galvos.

Here you go. I scanned in the complete Laser Media manual for these....

Personally I advise against hooking perfectly good G-120's to these things. I got tired of sending my galvos back to GS for torsion bar refits at around $350 a pop around 1994 or maybe 1995 and then wised up and bought some Turbotracks, ironically enough a unit that belonged to Pangolin at one point.....

You have been warned!

edit-- go find some used Accel 124 amps..... You will get better performance running your G120's as open loop galvos at 12K on accels than you ever will with this laser media garbage. Wider angle at 12K AND safer for the torsion bars

[Galvonaut]

Thank you Karl, that is much appreciated. Not sure I'm going to risk that amp but handy to have the manual, just in case

Keith