Patent ID: 7687940
Filing Date: 2010-03-30
Classification: H05B,Y02B

Abstract:
1. A dimmer switch adapted to be coupled to a circuit including an AC power source, a load, and a single-pole double-throw three-way switch, the three-way switch comprising a first fixed contact, a second fixed contact, and a movable contact adapted to be coupled to either the power source or the load, the three-way switch having a first state in which the movable contact is contacting the first fixed contact and a second state in which the movable contact is contacting the second fixed contact, the dimmer switch comprising: a first load terminal adapted to be coupled to either the power source or the load to which the three-way switch is not coupled; a second load terminal adapted to be coupled to the first fixed contact of the three-way switch; a third load terminal adapted to be coupled to the second fixed contact of the three-way switch; a controllably conductive device electrically coupled to the first, second, and third load terminals, the controllably conductive device having a conductive state in which the controllably conductive device is controlled so as to be operable to deliver a desired amount of power to the load and a non-conductive state in which the controllably conductive device is controlled so as to be operable to deliver substantially no power to the load, the controllably conductive device arranged such that when the controllably conductive device is in the conductive state and the dimmer switch is coupled to the circuit, the controllably conductive device is operable to allow a current to the load to flow between the first terminal and the second terminal or between the first terminal and the third terminal for at least a portion of each half-cycle of the AC power source; a sensing device electrically coupled to at least one of the second load terminal and the third load terminal, such that when the at least one of the second load terminal and the third load terminal is coupled to the three-way switch, the sensing device is operable to sense an electrical characteristic associated with the load terminal to which the sensing device is coupled; a controller operably coupled to the controllably conductive device and to the sensing device, the controller operable to control the controllably conductive device in response to an output of the sensing device in accordance with the electrical characteristic; and a power supply electrically coupled in shunt electrical connection with the controllably conductive device and operable to provide power to the controller.