This circuit is from an American 1967 documentation and can be implemented with modern equivalent transistors. The circuit serves as a Q multiplier.
In the circuit of the figure we used a potentiometer of 1 k ohm. We can use a larger...
We found this circuit in a 1987 Hands On Electronics. It was indicated at the time to power...
This interesting low current circuit uses only one diode to obtain a full wave rectified signal....