Electrical metering system having an electrical meter and an external current sensor
First Claim
1. An electrical metering system for measuring the power consumption of an associated electrical load coupled to a transmission line, said electrical metering system comprising:
- a current sensor, responsive to an electrical current conducted by the transmission line to the associated electrical load, configured to accurately produce an output signal of less than 2 mA, said output signal being related to the electrical current conducted by the transmission line, said current sensor configured to be electrically coupled to the transmission line and to the load to conduct at least a portion of the transmission line current supplied to the load; and
an electrical meter, responsive to said current sensor and a voltage sensing means, for tabulating load data related to the power consumption including power factor data of the associated electrical load based upon the output signals produced by said current sensor and said voltage sensing means, wherein said current sensor is external to said electrical meter and its housing such that said electrical meter is free of said current sensor.
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Accused Products
Abstract
An electrical metering system includes an electrical meter which is free of current sensors and an external current sensor for producing an output signal related to electrical current conducted by a transmission line to an electrical load associated with the electrical meter such that the power consumption of the electrical load can be computed by the electrical meter. The current sensor generally can include an unbalanced bridge circuit for producing a scaled output signal related, according to a predetermined ratio to the electrical current conducted by the transmission line. The electrical meter generally includes a register, responsive to the output signal produced by the external current sensor, to tabulate load data related to the power consumption of the associated electrical load. By employing an external current sensor capable of providing relatively large current transformation ratios, the electrical meter need not include a current sensor and the design of the electrical metering system can be greatly simplified.
80 Citations
20 Claims
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1. An electrical metering system for measuring the power consumption of an associated electrical load coupled to a transmission line, said electrical metering system comprising:
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a current sensor, responsive to an electrical current conducted by the transmission line to the associated electrical load, configured to accurately produce an output signal of less than 2 mA, said output signal being related to the electrical current conducted by the transmission line, said current sensor configured to be electrically coupled to the transmission line and to the load to conduct at least a portion of the transmission line current supplied to the load; and an electrical meter, responsive to said current sensor and a voltage sensing means, for tabulating load data related to the power consumption including power factor data of the associated electrical load based upon the output signals produced by said current sensor and said voltage sensing means, wherein said current sensor is external to said electrical meter and its housing such that said electrical meter is free of said current sensor. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An electrical metering system for measuring the power consumption of an associated electrical load, the electrical metering system comprising:
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a current sensor comprising bridge circuit means for receiving and dividing an electrical current conducted by a transmission line to the associated electrical load into predetermined portions, said bridge circuit means comprising; first and second branches for conducting first and second portions of the electrical current, respectively; and a center conductor for interconnecting said first and second branches and for conducting a current related to the electrical current conducted by the transmission line; said current sensor further comprising sensing means, magnetically coupled to said center conductor, for accurately producing an output signal of less than 2 mA related to the current conducted by said center conductor, wherein the magnitude of the output signal produced by said current sensor is less than a first determined maximum value; and an electrical meter for processing the output signals produced by said current sensor and a voltage sensing means, and for tabulating load data based upon the output signals of said current sensor and said voltage sensing means, wherein said current sensor is external to said electrical meter, and wherein the magnitude of the output signals of said current sensor which said electrical meter processes being no greater than a second predetermined maximum value, the second predetermined maximum value being greater than the first predetermined maximum value such that said electrical meter can process the output signals without further reducing the magnitude of the output signals. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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15. An electrical metering system for measuring the power consumption of an associated electrical load coupled to a transmission line conducting an electrical current, said electrical metering system comprising:
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a current sensor for accurately producing an output signal, said output signal being related to the electrical current conducted by the transmission line, said current sensor configured to be electrically coupled to the transmission line and to the load to conduct at least a portion of the electrical current supplied to the load, said current sensor configured to provide a transformation ratio of about 800A;
2 mA; andan electrical meter, responsive to said current sensor and a voltage sensing means, for tabulating load data related to the power consumption including power factor data of the associated electrical load based upon the output signals produced by said current sensor and said voltage sensing means. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification