This old circuit from the 80's generates logic signals with 50% active cycle (squares). The integrated circuit used is not common today, but equivalent logic functions can be used in a modern version.
This precision speed control was obtained in an Electronic Design from the 90's. The output final...
Using the name of varactor this circuit was found in the Radio Electronics magazine of July 1982....
This trigger circuit was found in an American documentation from the 1980s. The amplifiers used...