This circuit was found in the August 1997 Electronics Now magazine. The circuit uses well-known operational codes and generates signals up to 20 kHz.
This simple signal injector oscillator was found in a 1981 documentation. The coil can be made...
This variable oscillator was found in a Mullard transistors manual from 1960. The resistor R5 is...
This circuit is from an American 80's documentation. The circuit indicates when the voltage of a 9 V...