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.
In the figure we show how to trigger a triac for a continuous voltage of the order of 2 V,...
This 2005 Linear Technology circuit has separate outputs for monitoring the charge and discharge...
This circuit was obtained in a June 1987 magazine Hands-On. It is a circuit that indicates on two...