This circuit is from a 90s documentation. It has a hysteresis and uses a light sensing bridge. The circuit generates a 1000 Hz modulated 10 Hz signal. The signal must be applied to an amplifier.
This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit...
This countdown electromagnetic ring launcher was found in an Electronic Hobbyst Handbook from...
This TTL circuit was found in an American documentation from the 80s. The components are common in the...