This simple circuit for headphones or small speakers was found in documentation from the 90s. The circuit works with voltages from 5 to 9 V and has good gain.
This circuit was originally designed to automatically turn on a television when a video game is...
Designed by Philips in 1968 to control the washer water level this circuit uses components from the era....
This circuit uses an optical coupler called Raystor created by Raytheon in the 1960s. The circuit...