This circuit was found in a 1968 US publication. Transistors used are uncommon today. The circuit can be adapted to operate with modern equivalent components.
This circuit includes a battery charging system and an inverter for operating a fluorescent lamp....
This is one of the many versions of cricket that the reader can find on this site. This circuit is...
This circuit emits a sound when a magnetic field, of a magnet, for example, approaches the sensor....