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 was found in a 1977 Radio Shack documentation. Its purpose is to generate 1 Hz...
This circuit activates a relay that has a lamp as a load. The circuit is from a Radio Electronics from...
This circuit is from National Semiconductor documentation. The operational amplifier is of the...