Electronic kilowatt-hour meter for measuring electrical energy consumption
First Claim
1. A kilowatt-hour meter for determining, from voltage and current signals, the total energy passing through an alternating electrical supply circuit, said meter comprising a clock signal generator including a timing signal frequency generator for generating timing signals at a frequency which is a multiple of the alternating supply frequency and phase locking means for synchronising the phase of the timing signals with the phase of the alternating supply frequency, pulse sampling means controlled by the timing signals generated by said clock signal generator for sampling the magnitudes of the voltage on and current in the alternating electrical supply circuit at a preselected time in each cycle, and digital data processing means for processing the sampled data to determine energy consumption during successive predetermined periods of time and to integrate the successive determinations of energy consumption.
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Accused Products
Abstract
In a kilowatt-hour meter for measuring electrical energy consumption from an alternating electrical supply, a microprocessor includes a clock signal generator which is synchronized in phase with the incoming supply frequency. Pulse sampling means controlled by the clock generator sample the incoming voltage and current waveforms at a preselected time instant or instants in each cycle and the sampled data is utilized in the microprocessor to determine energy consumption.
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Citations
7 Claims
- 1. A kilowatt-hour meter for determining, from voltage and current signals, the total energy passing through an alternating electrical supply circuit, said meter comprising a clock signal generator including a timing signal frequency generator for generating timing signals at a frequency which is a multiple of the alternating supply frequency and phase locking means for synchronising the phase of the timing signals with the phase of the alternating supply frequency, pulse sampling means controlled by the timing signals generated by said clock signal generator for sampling the magnitudes of the voltage on and current in the alternating electrical supply circuit at a preselected time in each cycle, and digital data processing means for processing the sampled data to determine energy consumption during successive predetermined periods of time and to integrate the successive determinations of energy consumption.
Specification