SOLID STATE WATTHOUR METER

摘要

The solid state watt-hour meter (10) comprises a watthour (16) sensor adapted to be coupled to a consumer's connection to a source of electric power for sensing the voltage supplied to, and the current drawn by, the consumer's total electric load and for producing an output signal indicative of a quantity of watt-hours of power utilized by the consumer. The meter (10) includes a microprocessor (22) coupled to the watt-hour sensor (16) for receiving output signals thereform. An electrically alterable ROM (24) is coupled to the microprocessor (22). A power supply 18 having an input coupled to the consumer line voltage has an output coupled to the microprocessor (22) for supplying a regulated DC voltage thereto and includes means for supplying a 60 Hz clock signal to the microprocessor (22). A readout device (26) is coupled to the microprocessor for providing a readout of the power consumed since the last reading of the solid state watt-hour meter (10). A load control circuit breaker (132) in a consumer's circuit line to a consumer load (130), is connected to a load control output (123) of the microprocessor (22) and a microprocessor override switch (140) is coupled to the meter (10). The microprocessor 22 and electrically alterable ROM (24) are connected and programmed: (a) to sense the time of day as determined from an initial time of day and setting the 60 Hz clock signal; (b) to sense and totalize signals from the sensor (16) indicating the total power used by the consumer; (c) to provide a readout signal indicative of the total power consumed since the last reading of the meter; (d) to automatically open circuit the circuit breaker (132) for a time period during the time of day (daytime) when power demand on the electric power source is high and/or the cost per kilowatt hour is high; (e) to automatically close the circuit breaker (132) during the time of day (night-time) when the power demand on the source of electric power is low and/or the cost per kilowatt power is low; (f) to allow a consumer to override the microprocessor (22) control of the circuit breaker (132) by operating the override switch (140) to close the circuit breaker (132); and (g) to automatically reset the override switch (140) to the open position thereof when the microporcessor (22) is in the operating mode for automatically closing the circuit breaker (132).