This sequential circuit of LEDs was found in a Popular Electronics from the 90s. The circuit can be programmed and an adaptation consists of using optical couplers to drive power loads.
This circuit triggers a photographic flash when the microphone picks up a sound. The SCR can be...
We found this circuit in an old English documentation from the 70s. The transistor can be a modern...
Found in old English documentation, this circuit simulates a diac and can be used to trigger...