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.
Based on Allegro's A6275, this circuit controls the brightness of various displays. The circuit is valid...
This small transmitter can act as a wireless microphone operating in the medium wave range,...
This is the circuit of an RCA Dimmer sold in 1967. With it it is possible to control a load up to...