This circuit that imitates the sound of the cowboys' calls with their “louder” was found in a Hands On Electronics from the 80's. The integrated circuits used are from that time.
This circuit is intended to drive bistable relays and can be used as a shield for...
This circuit was found in Philips documentation from 1967. The phototransistor is from that time,...
This dual-gate FET RF signal mixer circuit was found in a 1980s documentation. The circuit is...