This commercial signal follower was found in a 1967 Japanese magazine. It uses germanium transistors and provides a speaker output without the need for a transformer.
Obtained in a 90s Radio Electronics, this configuration appears with variations in other points of...
This detector uses an unusual sensor today. The circuit is from an 80s documentation. Its...
This alarm with the 555 integrated circuit is from an EDN from the 90s. The circuit directly...