This circuit uses a contactor having been found in a 1987 publication. More modern equivalent devices may be used. The circuit has neon indicator lamps.
This circuit uses an optical coupler called Raystor created by Raytheon in the 1960s. The circuit...
This filter, found in an old manual, has characteristics of reduced overvoltage given by the graph...
The purpose of this circuit is to provide a few watts of power to a heavy speaker with good sound...