This 80's circuit uses a microcontroller programmed to generate various songs. The circuit can serve as the basis for a modern design, for example using Arduino. The old circuit included a small audio amplifier.
This is yet another version of the light-controlled oscillator that can be found on this website. This...
This filter operates in the “opposite” way to the previous one (CIR8814), cutting all signals...
This circuit is from a 1957 Japanese magazine, showing the use of OC19 in a high voltage inverter. The...