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.
Found in a 1970 EEE, this circuit uses general-purpose transistors of the time. Transistors support...
This simple source using fixed voltage regulators can supply currents up to 1 A at the voltages...
Originally suggested by Harris in the 1990s, this circuit uses an optical tachometer. The circuit is...