Good morning all! First time here. If there's a schematic repository somewhere, kindly nudge me in that direction, eh?
I just picked up a cheap Chinese galvo kit as a toy, and because there's no such thing as too much safety, a rotary solenoid shutter to go with it. I'm planning to do all my setup with a 5mw pointer, then drop in the RGB diode module later. The control board in the kit doesn't seem to include a shutter control (which is fine; I want this to be separate), so I'm planning to make a circuit that basically looks for the AC component of the X/Y drive signals, and holds the shutter open as long as there's motion. If the signals stop for any reason (static beam), one of the signals looks like DC, drop the shutter in front of the beam.
That seems straightforward enough, and an ideal "first op-amp project" for a digital nerd who rarely plays in the analog domain. Still, it'd be nice to use a proven schematic if there's one out there.
Then it hit me: I could conceivably drive this off the position sensor feedback coming off each galvo, which would also let me detect a seized galvo, mechanical damage, etc. Trouble is I bet those signals are really sensitive to some goober tapping their wiring... is this a terrible idea? Has it been done? Again, looking to avoid reinventing the wheel if possible.
Third-and-a-halfth question: I was looking at the ILDA DB25 pinout and noticed that the interlock is specified as just a short on the source, to be sensed somehow by the laser. How is this usually implemented? Seems to me that the most robust way would be to make a small oscillator and capacitively couple an AC signal into one of the interlock pins, then sense it coming back on the other. If it goes away for any reason, or if one of the pins is shorted to ground, or shorted to power, or floating, then there's no return and the laser doesn't enable. Is that how it's done?