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, which can only be used with incandescent lamps, is adapted to the common wall...
Audio frequencies in the 300 Hz to 30 kHz range can be measured with this circuit. Transistors allow...
In the event of a short in the output, the relay disarms interrupting the supply. To reset this...