Side looking occupancy sensor
A side looking occupancy sensor is incorporated in a conventional wall switch mounted into a switch box adjacent to a door. The side-looking proximity sensor preferably is mountable to either side of the doorjamb to make the side-looking proximity sensor face the door opening. During operation, the side-looking sensor monitors the door movement or senses the passage of a person for indication that a person is entering or leaving the space. Entry and exit determination is made based on activation of the side-looking sensor.
1. An occupancy sensing system comprising:
a load control device having a housing and controller;
a plurality of proximity sensors in the housing and operably coupled to the controller;
an occupancy sensor in the housing and operably coupled to the controller;
wherein a first proximity sensor of the plurality of proximity sensors is operable to monitor a first monitoring zone and a second proximity sensor is operable to monitor a second monitoring zone wherein the first monitoring zone is between the occupancy sensor and the second monitoring zone and the first and second monitoring zones are on one side of a door opening; and
wherein the controller is operable to monitor signals from the plurality of proximity sensors and upon detection of signals from the first proximity sensor indicating movement in the first monitoring zone and detection of a signal from the second proximity sensor indicating movement in the second monitoring zone such that the movement in the first monitoring zone is immediately before the movement in the second monitoring zone, indicating ingress detection, or immediately after the movement in the second monitoring zone, indicating egress detection, the controller controls operation of the load control device accordingly.
2. The occupancy sensor of claim 1 wherein the first and second proximity sensors pulse at different frequencies.
3. The occupancy sensor system of claim 1 wherein:
the controller is programmed to apply power to the electrical loads on ingress detection and disconnect power to the electrical loads on egress detection.