Found in American documentation from 1968, this circuit has an acute cut-off of the frequency to which it is tuned and which depends on RC. Transistors may be modern equivalents of general use.
This circuit is from a 1968 Electronic Design. The components are from the era and the operating...
In this charger the current is limited by the incandescent lamp. Lamps from 40 to 100 W can be...
This circuit was presented in a January 1990 Radio Electronics magazine article as part of a home...