Abstract: An electric device is provided as an interface between a permanent power source and an electrical appliance for maintaining the appliance, or a component thereof, in an operative state during a momentary power failure. The electric circuit includes an auto-transformer for increasing the induced back electric magnetic field voltage which is present in the line voltage of the permanent power source during a momentary power outage. The auto-transformer increases the induced back electric magnetic field voltage to a voltage level which is sufficient to maintain digital clocks or other low power-requiring components incorporated in an electrical appliance in an operative state during a momentary power outage.

Abstract: A solid state remote monitoring transmitter which transmits a 40 bit word that contains status information about a transformer via the secondary of a power distribution network to a central receiver associated with the primary (feeder) cable supplying the transformer. A program card specifies the carrier signal frequency and the identification of the transmitter. Multiple analog inputs are switched through a multiplexer to an A/D converter, the output of which is stored in a shift register to form the 40-bit word. The word is DPSK-coded by clock pulses in synchronism to the 60 Hz zero crossings of the AC power source and amplified by an unregulated power supply which is also powered by the AC power source. The phase transitions of th DPSK-coded word occur at the zero crossings diminishing any transients in the transmitter circuitry which would be caused by the phase transitions.