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DPRG: Laser Galvanometers

Subject: DPRG: Laser Galvanometers
From: Eric B. Olsen robojoc at worldnet.att.net
Date: Mon Feb 16 22:17:24 CST 1998


A kit as suggested by Dave Brown is good idea.

Glavo's, as they are sometimes referred, require lots of instantaneous power.  The
drivers on these boards (actually they are power op-amps) are usually quite large
and typically have large heatsinks on them.  The basic idea is that the Op-amps
are configured with the Galvo (or servo) to form a feedback loop.  The feedback is
generated by an optic sensor arrangement mounted on the servo that monitors the
position of the Galvo shaft.  During operation, the op-amp generates the output to
power the galvo, thus moving the shaft to the desired position in some
relationship to the applied input ... feedback keeps the unit from running out of

The mirrors on the shaft are light weight, and need to be attached to the Galvo's
very carefully.  Certainly, Safety should be a concern when setting this up, and
especially if demonstrating it to others.  A decent kit seems to be the best way
to go.

Eric Olsen

Dan Bowen wrote:

> I'm wondering if anyone knows where to find devices that I believe are called
> galvanometers - they are tiny mirrors that pivot by little electric coil, used
> in CD players sometimes.  Using 2 of these and one laser, one can create
> images with the laser beam (well, not really what you'd call images. :) I have
> one, but I do not know how to get my BS2 to make it move properly.  Any help -
> sources or BS2 programming (need to vary the voltage? on the coil precisely)
> would be greatly appreciated.  I'm a student, and I run the light board for
> the Talent show and I thought it would be awesome to adapt my robot brain to
> give a laser show!
> Thanks,
> Dan Bowen

- --

"Time will tell if the human race can handle the responsibility of it's own

Spectronix, Inc.
Henderson, NV

Email:  robojoc at postmaster.worldnet.att.net
Web-Site:  http://home.att.net/~robojoc/


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