Our beepboopboxen feel like they’re full of magic, and they are, so let’s make you a space wizard. We use the occult symbols of the circuit diagram to design electronics. In this case, we’re building an oscillator that generates positive and negative voltage (electrical “pressure”) that we can later plug into an amplifier that moves waves through the air.
Parts (probably get extra)
- 1× resistor kit from Dr. Evil or Ebay
- 1× electrolytic capacitor kit from same
- 1× MCP6002 dual op amp from DigiKey (~45¢). Get a bunch.
- 1× solderless breadboard
- 1× jumper wire kit
- 2× AAA battery holders + 4× AAA batteries
arcane symbols
The big electric ant in the middle of the page is a “chip” — an operational amplifier, or “op-amp”. Op-amps compare voltage between the two inputs at the base of the triangle. Send your signal into one input, wrap the output back to the other to make a feedback loop, and control it by changing the feedback. The − and + aren’t negative and positive, they’re inverting and non-inverting. Don’t blame me. Blame John Ragazzini.
An electrolytic capacitor fills up with electricity over time, and as it fills up it conducts less. So we use it to control how long something takes. With an oscillator, less time means a higher frequency, which is a higher pitch.
this oscillator design is adapted from Ancient Space Wizard Ray Wilson’s book Make: Analog Synthesizers. Rest in Space, Ray.