This small tone generator was found in the November 1987 issue of Radio Electronics magazine. The phototransistor is common and controls the sounds generated. The basic frequency is given by C1.
This circuit for demonstrating a sampling and holding configuration was found in a Popular...
This symmetrical limiter or reaper circuit is based on a zener diode. Voltage drop across common...
This switched power supply was found in a 70s documentation. The basic components are from that...