This circuit is from a 1967 RCA publication. The components are of the time, admitting equivalents, including the SCR that determines the maximum power of the load.
This circuit was obtained from an English circuit manual. Components are common and LEDs can be 3...
Found in a 90's EDN, this circuit generates signals in the frequency range given by the graph. The...
This circuit can generate signals from 100 kHz to 1 MHz depending on the L1 coil. For the medium...