Found in a 90s Popular Electronics, this circuit is based on a common CMOS component. The circuit triggers a buzzer by approaching objects from an antenna.
This transformerless 16-ohm speaker circuit was found in a Radio Electronics from October 1963. The...
This timer activates a relay after a time interval of up to 15 minutes has elapsed, starting from...
This circuit consists of a frequency-voltage converter. The circuit can be used as the basis for...