Kilowatt-hour meters.

摘要

in a kilowatt-hour meter for measuring electrical energy consumption from an alternating electrical supply, a microprocessor (20) includes a clock signal generator (22) which is synchronised in phase with the incoming supply frequency. Pulse sampling means (21) controlled by the clock generator (22) sample the incoming voltage and current waveforms at a preselected time instant or instants in each cycle and the sampled data is utilised in the microprocessor to determine energy consumption.