This circuit is from an old American publication, using transistors of the time and operating with a 48 V power source. The load is 2.2 ohm, and the transistors must be replaced by modern equivalents.
Mouser Electronics already has Intersil's IS8215M Power Step-Down modules, suitable for...
This tone recognizer circuit that relies on R5 and C1 was found in the December 1994 issue of...
In the figure we show how to use a varicap to modulate a signal in frequency. The circuit can be...