Power measurement in a two-wire load control device
First Claim
1. A two-wire lighting control device for controlling an amount of power delivered from an alternating current (AC) power source to a lighting load, the two-wire lighting control device comprising:
- a controllably conductive device configured to be coupled in series electrical connection between the AC power source and the lighting load;
a control circuit configured to render the controllably conductive device non-conductive during a first portion of a half-cycle of an AC waveform and render the controllably conductive device conductive during a second portion of the half-cycle to control the amount of power delivered to the lighting load;
a voltage measuring circuit configured to measure a voltage across the two-wire lighting control device during the first portion of the half-cycle;
a signal generator configured to generate a complementary voltage waveform that approximates a voltage across the lighting load during the second portion of the half-cycle, wherein the complementary voltage waveform is based on the voltage measured across the two-wire lighting control device during the first portion of the half-cycle; and
a current measuring circuit configured to measure a current supplied to the lighting load from the two-wire lighting control device during the second portion of the half-cycle;
wherein the control circuit is further configured to compute an estimated amount of power consumed by the lighting load based on the complementary voltage waveform and the current supplied to the lighting load during the second portion of the half-cycle.
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Accused Products
Abstract
A two-wire load control device may be configured to compute an accurate estimate of real-time power consumption by a load that is electrically connected to, and controlled by, the two-wire load control device. The load control device may be adapted to measure a voltage drop across the device during a first portion of a half-cycle of an AC waveform provided to the device. The device may be further configured to estimate a voltage drop across the load during the second portion of the half-cycle. The estimated voltage drop may be based on the measured voltage drop. The device may be further configured to measure a current supplied to the load during a second portion of the half-cycle. The device may be configured to estimate power consumed by the load based on the measured current and the estimated voltage drop.
56 Citations
10 Claims
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1. A two-wire lighting control device for controlling an amount of power delivered from an alternating current (AC) power source to a lighting load, the two-wire lighting control device comprising:
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a controllably conductive device configured to be coupled in series electrical connection between the AC power source and the lighting load; a control circuit configured to render the controllably conductive device non-conductive during a first portion of a half-cycle of an AC waveform and render the controllably conductive device conductive during a second portion of the half-cycle to control the amount of power delivered to the lighting load; a voltage measuring circuit configured to measure a voltage across the two-wire lighting control device during the first portion of the half-cycle; a signal generator configured to generate a complementary voltage waveform that approximates a voltage across the lighting load during the second portion of the half-cycle, wherein the complementary voltage waveform is based on the voltage measured across the two-wire lighting control device during the first portion of the half-cycle; and a current measuring circuit configured to measure a current supplied to the lighting load from the two-wire lighting control device during the second portion of the half-cycle; wherein the control circuit is further configured to compute an estimated amount of power consumed by the lighting load based on the complementary voltage waveform and the current supplied to the lighting load during the second portion of the half-cycle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification
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- Resources
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Current AssigneeLutron Technology Company LLC
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Original AssigneeLutron Electronics Company Incorporated (Lutron Electronics)
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InventorsBlakeley, Matthew Robert, Zotter, William
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Primary Examiner(s)Ahmad, Khaja
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Application NumberUS14/991,133Publication NumberTime in Patent Office991 DaysField of SearchNoneUS Class CurrentCPC Class CodesG01R 21/133 by using digital techniqueG05B 15/02 electricG05F 1/12 wherein the variable actual...G05F 1/66 Regulating electric powerG06F 1/26 Power supply means, e.g. re...H05B 39/04 ControllingH05B 47/175 by remote controlY02B 20/00 Energy efficient lighting t...
