Using 4 operational amplifiers this circuit generates 4 different tones. The circuit is from an American documentation from the 90's. Operational amplifiers are tTL084.
This circuit shows how to use the remaining gates of a 4093 or 74C14 as amplifiers. The circuit has...
This is the basic configuration of a Colpitts LC oscillator using a CMOS gate. ...
This circuit was found in a 1969’s American documentation. It shows how to use two transistors to form...