Patent ID: 9299524
Filing Date: 2016-03-29
CPC Classification: H01H

Claim Text:
1. A method for providing temporary power to an electrical load during momentary disturbances in an electrical power supply that provides an input AC line voltage to the electrical load, comprising the steps of: providing a microprocessor for sensing a representative AC voltage corresponding to an instantaneous value of the input AC line voltage and for providing a switching signal in response to detection of a momentary disturbance in the electrical power supply; providing a selectively actuatable switch coupled between the electrical power supply and the electrical load, the switch responsive to the switching signal provided by the microprocessor to be placed in either (i) a first switching state wherein the electrical load is directly coupled to the electrical power supply, or (ii) a second switching state in which the direct coupling is opened such that the load is disconnected from the electrical power supply; providing a ride-through circuit comprising a first resistance, a second resistance, a diode, and a capacitance that charges from the electrical power supply through the diode and the first resistance when the switch is in the first switching state, the capacitance discharging through the second resistance to provide temporary power to the electrical load when the switch is in the second switching state; upon detection by the microprocessor that the representative AC voltage indicates a momentary disturbance in the electrical power supply, changing the selectively actuatable switch from the first switching state to the second switching state such that the load is connected to the ride-through circuit for providing temporary power to the electrical load; upon detection by the microprocessor that the representative AC voltage has returned to normal operating conditions, returning the selectively actuatable switch to the first switching state for recharging the capacitance.