Found on 80's Popular Electronics this circuit operates at 455 kHz. The explorer coil is formed by 10 turns of yarn 26 in a 4 inch shape. The indicator is a microammeter.
This 1989 circuit activates a protection relay if one or two phases are missing from a three-phase...
This simple TTL electronic dice uses common anode displays. The circuit is from a March 1975 Radio...
This non-pulse alarm can be used as an event detector or even an alarm. The circuit can also be...