This circuit makes use of a specific 80's component and was found in an American manual of the time. A matrix keyboard allows you to select one of several music programs.
This circuit, which can only be used with incandescent lamps, is adapted to the common wall...
This is the simplest configuration of a voltage regulator with a zener diode. The resistor must be...
This circuit was found in an English documentation from 1989. The transistors support...