This circuit automatically turns off small battery-powered devices after a certain amount of time, saving battery life. We found it in a Popular Electronics from the 90s.
This circuit, which is part of a percussion instrument, was found in the September 1979 issue of...
The diodes are for general use and the transistors also in this Exclusive-OR circuit. The circuit may...
The frequency of this small transmitter, from a 1978 foreign publication, depends on the crystal. The...