SYSTEM AND METHOD FOR FAIL SAFE OPERATION OF LOW VOLTAGE OCCUPANCY SENSORS
First Claim
1. A load control system, comprising:
- an occupancy sensor for providing an occupancy signal representative of occupancy of a monitored area, and for providing a health signal representative of a health of the occupancy sensor;
a load control device coupled to the occupancy sensor, the load control device configured to receive the occupancy signal and the health signal from the occupancy sensor, and to control an electrical load based on at least one of the received occupancy signal and the health signal.
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Accused Products
Abstract
A system and method are disclosed for providing fail-safe operation of an occupancy sensor so that a load associated with the sensor will be energized in the event that the sensor malfunctions. Short voltage pulses are applied to a signal line by an occupancy sensor. A load control device recognizes the pulses as an indication that the sensor is in a healthy condition. If the load control device does not recognize the voltage pulses, it assumes the sensor is faulty and energizes the load (light) associated with the monitored space. The voltage pulses are different from the normal signals sent by the sensor to the load control device that indicate an “occupied” condition of the space. Other embodiments are described and claimed.
35 Citations
26 Claims
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1. A load control system, comprising:
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an occupancy sensor for providing an occupancy signal representative of occupancy of a monitored area, and for providing a health signal representative of a health of the occupancy sensor; a load control device coupled to the occupancy sensor, the load control device configured to receive the occupancy signal and the health signal from the occupancy sensor, and to control an electrical load based on at least one of the received occupancy signal and the health signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for controlling an electrical load using an occupancy sensor, comprising:
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receiving, at a load control device, a health signal representative of a health status of the occupancy sensor; receiving, at the load control device, an occupancy signal representative of an occupancy status of a monitored space; and controlling an electrical load based on at least one of the occupancy signal and the health signal. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification