This circuit is from a 1968 Electronic Design. The characteristics of the output transformer are not given and the transistors are of the time. The circuit provides a power of a few watts.
Capacitor C and resistor R in this circuit determine the time the output remains at the high level...
The purpose of this circuit is to extend the range of applications from a Darlington pair to DC....
Found in an old English publication this circuit uses a dual gate MOSFET. Coils not specified....