General Scanning Galvo?

[Ed Wesly]

I recently found this galvo scanner.



I presume the General Scanning logo is hidden under the cable relief pad, as the patent mentioned on it, 3,624,574 is a Montagu one. The Model No. is Z 519, Serial No. 28149. Would anyone here be kind enough to give me some info on this unit, as I have searched the web in vain and come up with nothing as far as what the red, yellow, green black wires are for (2 for the stator, the others for the rotor, but which ones?), what kind of power to feed them, what are its operating limits in regards to angle of deflection and speed, and when approximately was it built?

Since I only have the one, plus a Spectra-Physics mirror polygon, I would like to make this into an optical oscilloscope, plugged into an audio output of some sort, who cares if it is frequency challenged, it still would look cool.

Thanks in advance, I enjoy the activity here, even though I am more in the holography side of things like Bob and Jem, I do like to light up the lab with plenty of beams! Plus I seem to be falling into the trap of collecting these things!

http://www.chicagoreader.com/chicago...Tj1EIf6A.gmail

[Photonbeam]

Open loop General Scanning galvo. The four wires are the coil wires allowing you to run the coils series or parallel. Normally you would tie the red to green and yellow to black. Not fast enough for graphics but you could use it with your polygon. Go ahead and connect it to an audio amp output (careful not to overdrive) and have fun!

[mixedgas]

If I remember right its tie black to green and drive red to yellow for series coils.
Use the simple A102 amplifier schematic on the Cambridge Technology legacy website for adding damping to the open loop.

Steve

[Photonbeam]

If I remember right its tie black to green and drive red to yellow for series coils.
Use the simple A102 amplifier schematic on the Cambridge Technology legacy website for adding damping to the open loop.

Steve

Steve - Yes that would put the coils in series. I recognize the wire colors from G100PD/G120PD's and remember mine were always wired in parallel - black to yellow and red to green. What would be the advantages/differences in wiring the coils series or parallel? Impedence?

[mixedgas]

Steve - Yes that would put the coils in series. I recognize the wire colors from G100PD/G120PD's and remember mine were always wired in parallel - black to yellow and red to green. What would be the advantages/differences in wiring the coils series or parallel? Impedence?

Makes it hard to exceed the 2.25 amps that demagnetizes the galvo, otherwise more inductance. Brings it to 7.25 ohms reactive where it looks like a 8 Ohm speaker to a amplifier. Sensitivity goes to a more reasonable place for small signals.

Steve

[Ed Wesly]

Thanks for the replies! I will try them out today.

Good thing I asked, I would never have thought to put the wires together like that!

Will report back when I get it working!

[Photonbeam]

Makes it hard to exceed the 2.25 amps that demagnetizes the galvo, otherwise more inductance. Brings it to 7.25 ohms reactive where it looks like a 8 Ohm speaker to a amplifier. Sensitivity goes to a more reasonable place for small signals.

Steve

Yes that makes sense.

[Ed Wesly]

And it does work! Just tried it!

Thanks a lot for the help, I also used the laserfx.com web site, is that one done by somebody here? Steve? It is very well done, and if anyone reading this hasn't been there, it is definitely worth a trip!

One more question about this galvo or in general: what do they look like inside? Mentally I could image them like any d'Arsonval movement, rotating coils on a shaft, surrounded by a magnet, but then the business of coli 1 and coil 2 came up and threw me for a loop.

So if anyone could post a picture of the guts of one, or knows a site that has one, that would be great to see! Since this antique I have (I'm thinking early '80's is the Z 519's vintage?) is working I don't want to put it out of commission on account of my curiosity.

Thanks again!

[laserist]

The Z-519 was what Laser Images used in the Mark IV projector used to do Laserium I. The Mark VI projector used G-124 scanners and was introduced with Laserium II in 1976. These are (I believe) what are called moving iron scanners. The magnet(s) and coils are potted in the housing.

And it does work! Just tried it!

Thanks a lot for the help, I also used the laserfx.com web site, is that one done by somebody here? Steve? It is very well done, and if anyone reading this hasn't been there, it is definitely worth a trip!

One more question about this galvo or in general: what do they look like inside? Mentally I could image them like any d'Arsonval movement, rotating coils on a shaft, surrounded by a magnet, but then the business of coli 1 and coil 2 came up and threw me for a loop.

So if anyone could post a picture of the guts of one, or knows a site that has one, that would be great to see! Since this antique I have (I'm thinking early '80's is the Z 519's vintage?) is working I don't want to put it out of commission on account of my curiosity.

Thanks again!

[Ed Wesly]

So it's possible that this is a '70's vintage device?