Found in a 1970 EEE, this circuit uses general-purpose transistors of the time. Transistors support equivalents and the ramp time ranges from 0.1 seconds to a few seconds, depending on C1.
The figure shows how to implement an audio power output for an operational stage. With the...
This control from a 1989 publication can be assembled with several equivalent components. The SCR,...
This power supply with several transistors can supply a current of several amps and a voltage of...