This circuit provides a reference voltage of 2.5 V adjusted in the trimpot. The transistor can be the BC558 (in the drawing it came out as NPN). The control is done by a rectangular input signal.
The main feature of this circuit is that it provides a sine waveform signal. In this circuit, the...
This circuit behaves as a voltage controlled resistor and can serve as a small load. The circuit is...
The circuit presented, from a 2005 documentation, can provide from 1 W to 2.5 W of output when...