I was reaing Instructables this weekend, and I came across a project that someone had done that used audio speakers like galvanometers (galvos) to actually move a laser beam around! The project has full X-Y control of the laser beam, and with a wee little Arduino microcontroller, you have yourself a fully programmable laser show for about 50 bucks. Pretty awesome.
Have you never seen a laser device that spells words and makes pictures and such? Inside of those devices are several little things called galvanometers – in the laser world, we call them galvos, or a galvo, singular. These things are basically moving coil electric current detectors, pure and simple. When a voltage is applied, they react. When a voltage is applied and changed several times a second, you see all kinds of little erratic movements in the galvo. With laser shows and devices that utilize galvos to spell words and draw pictures with lasers, what is happening is that the voltage is being changed rapidly and constantly in order to make the laser appear to be spelling out these words and pictures.
Pretty simple and awesome, yeah?
You have to check out this amazing Instructables method for building this awesome little DIY galvo laser show. It’s well worth a few Monday morning minutes! Here’s a video of the system in action: