We found this circuit in a 1960 Radioarama magazine. The instrument tests common general-purpose transistors indicating their gain on a moving coil instrument. The loop serves to adjust the circuit.
The output current of this power supply depends on the power transistor and the transformer and...
This voltage inverter uses a small transformer. The circuit was found in the April 1995 issue of...
This 1969 Popular Electronics circuit was based on the then recently released BC109, today with...