Dual circuit wall switch occupancy sensor and method of operating same

• US 20090115385A1
• Filed: 09/15/2008
• Published: 05/07/2009
• Est. Priority Date: 05/27/2005
• Status: Active Grant

• Current Assignee: Hubbell Lighting Incorporated (Hubbell, Inc.)
• Original Assignee: Jonathan D. Williams, Thomas J. Hartnagel, Todd J. Blackmon, Vadim Konradi
• Inventors: Blackmon, Todd J., Williams, Jonathan D., Hartnagel, Thomas J., Konradi, Vadim
• Granted Patent: US 7,830,133 B2
• Time in Patent Office: Days
• US Class Current: 323/282
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: H05B 47/13 by using passive infrared detectors
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection
• CPC Class Codes: Y10S 323/908 Inrush current limiters

Abstract

A method and apparatus are provided for detecting occupancy in an area using multiple detection technologies (e.g., ultrasound and infrared sensing) to intelligently control switching of plural load circuits whereby one of the circuits is affected by photocell control. A programmable controller implements auto-on, manual-on, reversion to auto-on and override operations with respect to the separately controlled load circuits based on sensor outputs and user inputs. An improved power supply for an occupancy sensor and load control device employs a DC voltage derived from leakage AC voltage between line and ground to drive the sensors and other circuits, and a switching regulator with a switching cycle controlled by a pulse width modulated (PWM) subsystem of the apparatus, allowing synchronous, delayed or exclusive operation relative to the sensing technology such as the US transmitter.

Claims

1. A method of supplying power to an occupancy-based load controller comprising the steps of:

applying power to a current limiting circuit, the current limiting circuit being configured to limit one of leakage to ground current and leakage to neutral current to a selected level;

accumulating charge in a capacitance circuit disposed at the output of the current limiting circuit;

selectively controlling discharge of the capacitance circuit into a power rail for powering a load connected between the power rail and ground; and

receiving a pulse signal;

wherein said selectively controlling step comprises providing current discharged from the capacitance circuit to the power rail during a first portion of the pulse signal and interrupting the supply of current discharged from the capacitance circuit to the power rail during a second portion of the pulse signal.