This circuit was obtained in a 1968 manual of General Electric. The components used are of the time, but they admit equivalent. Observe the optical feedback system for control.
This circuit was obtained from an old documentation, but as it uses still current components it can be...
This audio circuit has an output power of 1 W. We found it in the Radio Electronics magazine of...
This circuit that uses only discrete components (transistors) mimics the sound of an American...