Published in Popular Electronics with the curious name of Obnoxious Noisemaker, this 1968 circuit generates random sounds that are reproduced on a loudspeaker. The power transistor can be a BD136.
The drive levels of this shield are opposite to the previous one. The photo-transistor can be of...
This circuit was found in a Radio Electronics of July 1984. It consists of the traditional 1 A...
This flasher or neon signal powered by batteries was found in old documentation. The transformer must...