This two-channel bargraph meter uses a single KAA2281 integrated circuit. Found in the January 1991 issue of Radio Electronics magazine. The stereo circuit drives 2 scales of 5 LEDs.
We find this circuit in an old documentation, but it can be made using modern transistors. The circuit...
We found this circuit in a spy book from the 90s. Transistors admit equivalents and the coil can...
The circuit shown was found in an American documentation from 1964. The circuit uses transistors of...