Found in Philips' 90s documentation, this small source can use modern transistors like the BD135 for TR4 and the BC series for the rest.
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...