This simple circuit makes use of neon lamps to indicate the voltage of a power grid. The lamps are common neon and the circuit indicates whether the voltage is 110 V or 220 V.
This old circuit for circuit breaker cars was found in a 1963 publication. The transistors are...
This circuit was obtained in a 1973 national publication, translated from an English publication of the...
Found in an October 1992 Radio Electronics magazine article, this circuit generates a low-power tone in...