First Light

A project log for Laser Galvo Clock

Clock projected onto the wall with cheap laser galvos

Alan GreenAlan Green 06/08/2019 at 11:220 Comments

In which I wire up the laser galvos in minimal way, validate some concepts and learn some new things.

Turning on The Galvos

Here's what I did. At each step I was careful to test to make sure that no smoke came out and that everything behaved as expected. 

  1. Wired up the power supply to a mains plug,
  2. Connect power to the driver boards
  3. Connect the driver boards to the galvos

At that last step, the galvos moved! I had not been expecting them to move, but it seems that their off position is at one end of their range.

At this point, I used Blu-Tack to hold everything down, just to make sure nothing got lost in the tangle of wires. These are the grey blobs you can see in the photos above.

I then stole the cat's spare laser pointer, Blu-Tacked it in place and lo! there was a dot.

Signal Generator and Pretty Patterns

I have a dual-channel signal generator. Using a Blue Board #01 I soldered up a couple of connections. Each driver board is fed by three wires: ground, V+ and V-, with V+ and V- carrying a differential signal of up to 10V. I tied each driver board's V- signal to ground, then piped in the signal to V+.

The resulting patterns look different on camera than they do in real life, but are interesting nonetheless. The shapes are correct even if the colors are not.

Lissajous Pattern
The ABC of Lissajous
Another pattern, Lissajous like
Space uniform logo
3rd example Lissajous pattern
Neon crochet pillow

Here are some things I learned:

I think this is going to work!