Electricity meter
First Claim
1. A meter for measuring electricity usage for a given load, said meter comprising:
- a housing;
a first light source and a second light source, each said light source disposed in said housing and configured to output light at a predetermined frequency;
a first light receiver and a second light receiver, wherein each said light receiver is disposed in said housing so that a first light path is defined between said first light source and said first light receiver and so that a second light path is defined between said second light source and said second light receiver, and wherein each said light receiver is configured to receive said light from its respective said light source and to output a signal responsively thereto at a frequency related to said predetermined frequency by a predetermined relationship;
a rotatable member disposed in said housing and being rotatable responsively to said electricity usage, said rotatable member defining a first portion and a second portion so that said first portion and said second portion alternatingly intercept each of said first light path and said second light path as said rotatable member rotates, wherein said first portion transmits incident light from a said light source to its respective said light receiver and wherein said second portion blocks said incident light, and wherein one of said first portion and said second portion is defined on said rotatable member so that said one of said first and second portions can intercept only one of said first light path and said second light path at a time; and
a filter circuit including two band pass filters, each in communication with a respective one of said first light receiver and said second light receiver, wherein each said band pass filter receives said output signal from its said respective light receiver and passes a frequency range that includes said related frequency so that said band pass filter outputs a signal at said related frequency upon receipt of said light receiver output signal, two acquisition circuits, each in communication with a respective one of said band pass filters, wherein each said acquisition circuit receives said output signal from its said respective band pass filter and is configured to output responsively thereto a signal having a magnitude based on the magnitude of said band pass filter output signal, and two comparator circuits, each in communication with a respective one of said acquisition circuits, wherein each said comparator circuit receives said output signal from its said respective acquisition circuit and is configured to compare said acquisition circuit output signal with a threshold voltage and output a signal in one of two states depending on said comparison.
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Accused Products
Abstract
A meter for measuring electricity usage for a given load includes a housing and two light sources disposed in the housing and configured to output light at a predetermined frequency. Two light receivers are disposed in the housing so that a light path is defined between each light source and its respective light receiver. Each light receiver is configured to receive the light from its light source and to output a signal responsively thereto. A rotatable member is disposed in the housing in the light paths and is rotatable responsively to the electricity usage. The member has a first portion and a second portion. The first portion transmits incident light while the second portion blocks light. The first portion and the second portion are defined on the member so that the member modulates the light as it rotates. A filter circuit in communication with the light receiver is configured to receive the output signal from the light receiver and to detect therefrom modulation of the light by the rotatable member.
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Citations
16 Claims
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1. A meter for measuring electricity usage for a given load, said meter comprising:
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a housing;
a first light source and a second light source, each said light source disposed in said housing and configured to output light at a predetermined frequency;
a first light receiver and a second light receiver, wherein each said light receiver is disposed in said housing so that a first light path is defined between said first light source and said first light receiver and so that a second light path is defined between said second light source and said second light receiver, and wherein each said light receiver is configured to receive said light from its respective said light source and to output a signal responsively thereto at a frequency related to said predetermined frequency by a predetermined relationship;
a rotatable member disposed in said housing and being rotatable responsively to said electricity usage, said rotatable member defining a first portion and a second portion so that said first portion and said second portion alternatingly intercept each of said first light path and said second light path as said rotatable member rotates, wherein said first portion transmits incident light from a said light source to its respective said light receiver and wherein said second portion blocks said incident light, and wherein one of said first portion and said second portion is defined on said rotatable member so that said one of said first and second portions can intercept only one of said first light path and said second light path at a time; and
a filter circuit including two band pass filters, each in communication with a respective one of said first light receiver and said second light receiver, wherein each said band pass filter receives said output signal from its said respective light receiver and passes a frequency range that includes said related frequency so that said band pass filter outputs a signal at said related frequency upon receipt of said light receiver output signal, two acquisition circuits, each in communication with a respective one of said band pass filters, wherein each said acquisition circuit receives said output signal from its said respective band pass filter and is configured to output responsively thereto a signal having a magnitude based on the magnitude of said band pass filter output signal, and two comparator circuits, each in communication with a respective one of said acquisition circuits, wherein each said comparator circuit receives said output signal from its said respective acquisition circuit and is configured to compare said acquisition circuit output signal with a threshold voltage and output a signal in one of two states depending on said comparison. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification