PC address decoder (CB20536E)

This TTL decoder circuit for PC ports was found in a document from 1992. The power supply can be PC's own circuit.

Simple 555 Timer (CB12816E)
With a touch of the sensor wire X1, which can also be a pressure switch, the LED lights for a time...
Alarm with Shutdown (CB24375E)
This alarm with automatic shutoff was found in the April 1975 Radio Electronics magazine. The...
10 to 84 MHz Colpitts oscillator (CB4052E)
This Colpitts crystal oscillator was found in an American publication for amateurs in the 1980s....