Found in 90s Popular Electronics, this circuit uses common general-purpose transistors in a configuration that has been extensively explored on this site and in our articles.
The circuit shown in the figure allows a pressure switch to be used to turn a load on and off in a...
Raytheon's used integrated circuit is no longer common today. The circuit was obtained in a...
Found in a 1968 Electronic Design, this circuit makes use of an unusual ultrasonic delay line...