Found in a 1970s documentation, this mini-organ toy circuit makes use of an integrated circuit from that time. This component is difficult to obtain today.
Hughes suggests this circuit in a 1968 documentation. The circuit uses old transistors that can be...
Using a single Darlington phototransistor, this circuit drives a highly sensitive relay, for...
This source whose voltage depends only on the zener diode used, can supply currents up to about 3 A....