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 circuit consists in a capacitor bridge for capacitance measurements. The circuit can be...
This switched circuit was found in an old documentation and no information about the transformer...
This circuit was found in an American 1980s documentation. The transistorized step is the...