This audible continuity test was obtained in a book from the 90's describing simple projects. The feeding is done with a single battery.
This symmetrical power source for currents up to 1 A was found in a 1986 documentation, serving...
This circuit synthesizes the tick of a metronome with the speed controlled in RV1. The circuit is...
Found in Radio Electronics from the 90s, this circuit generates signals from 100 Hz to 1.5 kHz....