Laser Show

2 minute read

After my first attempt:

  • ARM-7 corte m-3 @72Mhz
  • two voice-coils out of old Harddisks.
  • two light to frequency generators
  • By optical feedback I opt to create an close-loop PID-control loop. The result wasn’t what I intented it to be.

As it turned out, the arm CPU wasn’t fast enough, that combined with poor hardware, (old harddisks, hot glue :), on a steady base of wood…), I bought some (more) serious stuff.

  • 20K Galvo’s
  • Galvo drivers/Amps
  • Symmetric powersupply
  • 12V powersupply (for the dac)
  • Opamps, potentiometers, resistors and voltage-converter
  • Separate laser diodes, dichroic mirros (to combine the rays)
  • Laser driver circuitry (consists of opamp)
  • Laser RGB brick
  • ShowCard  

After assembling the whole lot (on a cutting board for food :)), the rather compact box is shown below.

IMG_0032

You can clearly see the two power supplies (aluminium cases), the two drivers for the galvos’ (right bit), and the RGB laser brick (which needed to be calibrated a bit more).

I also build the USB-soundcard to ILDA converter board, it consists of 6 discrete op-amp circuits, to compensate for the sound-card’s offsets. It taps into the dac-outputs prior to the decoupling caps.

The stock showcard’s show is rater nice, but when your running your own graphs, people will be amazed even more :)

*oh did I mentioned that i bough a smoke-machine as well, quite the must-have for laser-enthousiasts!

http://youtu.be/BvFx6ribKmY

So I build the converter-amp, and started to get some proper animations :)

A spinning bottle:

http://youtu.be/8YzqM540KS4

A simple concatenation of figures:

http://youtu.be/Fd0KsKaqnvI

Beam shows (with smoke machine):

http://youtu.be/Wr89qrYGhWI