Dual circuit wall switch occupancy sensor and method of operating same
First Claim
1. A power supply for a load controller comprising:
- a rectifier circuit having a first input terminal connected to the hot terminal of an AC power source, a second input terminal connected to one of ground and neutral, and a third output terminal and a fourth output terminal connected to a DC power rail and a DC return rail respectively;
a current limit circuit connected to said rectifier circuit comprising a current limiting device and a first capacitor, said current limiting device being configured to limit the corresponding one of leakage current to ground and leakage current to neutral, to a selected average level; and
a regulator, said first capacitor being connected across said regulator, said regulator comprising a DC power input, a control input for receiving a pulse signal, a DC power output connected to said DC power rail and operable to provide power to a DC load when said DC load is connected with one load terminal thereof to said DC power rail and another load terminal thereof to said DC return rail, a main switch and an energy storage device connected between said DC power input and said DC power rail, a control switch, and a shunt regulator connected between said DC power rail and one of ground and said DC return rail for clamping said DC power rail to provide a shunt regulated output for said regulator, said control switch controlling operation of said main switch to be selectively opened and closed in accordance with said pulse signal to attain a selected duty cycle that determines a voltage on said first capacitor when current out of said first capacitor is limited by said selected level of said current limit circuit, said energy storage device providing power to said DC power rail when said main switch is open until said energy storage device has depleted energy stored therein.
6 Assignments
0 Petitions
Accused Products
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.
-
Citations
23 Claims
-
1. A power supply for a load controller comprising:
-
a rectifier circuit having a first input terminal connected to the hot terminal of an AC power source, a second input terminal connected to one of ground and neutral, and a third output terminal and a fourth output terminal connected to a DC power rail and a DC return rail respectively; a current limit circuit connected to said rectifier circuit comprising a current limiting device and a first capacitor, said current limiting device being configured to limit the corresponding one of leakage current to ground and leakage current to neutral, to a selected average level; and a regulator, said first capacitor being connected across said regulator, said regulator comprising a DC power input, a control input for receiving a pulse signal, a DC power output connected to said DC power rail and operable to provide power to a DC load when said DC load is connected with one load terminal thereof to said DC power rail and another load terminal thereof to said DC return rail, a main switch and an energy storage device connected between said DC power input and said DC power rail, a control switch, and a shunt regulator connected between said DC power rail and one of ground and said DC return rail for clamping said DC power rail to provide a shunt regulated output for said regulator, said control switch controlling operation of said main switch to be selectively opened and closed in accordance with said pulse signal to attain a selected duty cycle that determines a voltage on said first capacitor when current out of said first capacitor is limited by said selected level of said current limit circuit, said energy storage device providing power to said DC power rail when said main switch is open until said energy storage device has depleted energy stored therein. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A power supply for a load controller comprising:
-
a rectifier circuit having a first input terminal connected to the hot terminal of an AC power source, a second input terminal connected to one of ground and neutral, and a third output terminal and a fourth output terminal connected to a DC power rail and a DC return rail respectively; a current limit circuit connected to said rectifier circuit comprising a current limiting device and a first capacitor, said current limiting device being configured to limit the corresponding one of leakage current to ground and leakage current to neutral, to a selected average level; and a regulator, said first capacitor being connected across said regulator, said regulator comprising a DC power input, a control input for receiving a pulse signal, a DC power output connected to said DC power rail and operable to provide power to a DC load when said DC load is connected with one load terminal thereof to said DC power rail and another load terminal thereof to a DC return, a main switch and an energy storage device connected between said DC power input and said DC power rail, and a control switch, said control switch controlling operation of said main switch to be selectively opened and closed in accordance with said pulse signal, said energy storage device providing power to said DC power rail when said main switch is open; wherein said pulse signal is a periodic signal having cycles that comprises a first portion and a second portion in each cycle thereof, said main switch being operable to close and open in response to said first portion and said second portion, respectively, said main switch being operated and providing power to said DC power rail substantially synchronously with operation of an occupancy sensor for said load controller during said first portion of said pulse signal. - View Dependent Claims (12, 13, 14)
-
-
15. A power supply for a load controller comprising:
-
a rectifier circuit having a first input terminal connected to the hot terminal of an AC power source, a second input terminal connected to one of ground and neutral, and a third output terminal and a fourth output terminal connected to a DC power rail and a DC return rail respectively; a current limit circuit connected to said rectifier circuit comprising a current limiting device and a first capacitor, said current limiting device being configured to limit the corresponding one of leakage current to ground and leakage current to neutral, to a selected average level; and a regulator, said first capacitor being connected across said regulator, said regulator comprising a DC power input, a control input for receiving a pulse signal, a DC power output connected to said DC power rail and operable to provide power to a DC load when said DC load is connected with one load terminal thereof to said DC power rail and another load terminal thereof to a DC return, a main switch and an energy storage device connected between said DC power input and said DC power rail, and a control switch, said control switch controlling operation of said main switch to be selectively opened and closed in accordance with said pulse signal, said energy storage device providing power to said DC power rail when said main switch is open; wherein said pulse signal is a periodic signal that comprises a first portion and a second portion in each cycle thereof, said main switch being operable to close and open in response to said first portion and said second portion, respectively, said first portion of said pulse signal being generated at a selected phase difference with respect to operation of an occupancy sensor for controlling said load controller. - View Dependent Claims (16)
-
-
17. 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 an 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; providing a shunt regulator across the power rail and ground; and receiving a pulse signal; wherein said selectively controlling step comprises controlling a duty cycle of a switch by selective controlling the opening and closing of said switch in accordance with said pulse signal to determine voltage on said capacitance circuit when current out of said first capacitor is limited by said selected level of said current limiting circuit. - View Dependent Claims (18, 19)
-
-
20. 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 an 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; wherein said pulse signal is periodic and comprises cycles each having the first portion and the second portion therein, and said selectively controlling step comprises the step of switching current to the power rail on and off with the occurrence of each said first portion and second portion, respectively; and further comprising the step of operating an active occupancy detector configured to transmit occupancy detection signals at the same frequency as said pulse signal, and with a phase relationship substantially invariant with respect to said pulse signal. - View Dependent Claims (21, 22, 23)
-
Specification