This sound intensity meter was found in a 90s Elektor. The circuit uses an integrated device from the time that is not common today. The indicator is a milliammeter.
This circuit is from a 1975 magazine, but it is still current as all components are common. The...
This PNP transistor power stage was found in the May 1969 issue of Radio Electronics magazine. The circuit...
This circuit is suitable for incandescent lamps but can be adapted to work with LEDs. The circuit is...