Abstract: A dimmer switch coupleable to a circuit including a power source, load, and single-pole double-throw three-way switch that comprises a first and a second fixed contact and a movable contact. The three-way switch has a first state and a second state. The dimmer switch comprises first, second and third load terminals coupled in series with the three-way switch. The dimmer switch comprises a controllably conductive device. A sensing device is coupled to the third load terminal such that when the three-way switch is in the second state, the sensing device is operable to sense an electrical characteristic associated with the third load terminal. A controller is coupled to the controllably conductive device and to the sensing device for rendering the controllably conductive device conductive in response to the sensed electrical characteristic and so that power is delivered through the second load terminal of the third load terminal depending on the state of the three-way switch.

Abstract: A dimmer switch coupleable to a circuit including a power source, load, and single-pole double-throw three-way switch that comprises a first and a second fixed contact, and a movable contact. The three-way switch has 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 comprises first, second and third load terminals coupled in series with the three-way switch. The dimmer switch comprises first and second controllably conductive devices, such that the first and second controllably conductive devices are operable to conduct load current to control the amount of power delivered to the load when the three-way switch is in the respective first and second states; and a controller coupleable to the first and second controllably conductive devices for rendering the first and second controllably conductive devices conductive and non-conductive.

Abstract: A smart dimmer switch for control of a lighting load from an AC voltage source can replace any switch in a three-way or four-way lighting control system. The smart dimmer switch can be connected on the line-side or the load-side of a three-way system with a standard three-way switch in the other location. Further, the dimmer switch can replace a four-way switch in a four-way system and is operable to be coupled to two standard three-way switches. The dimmer switch includes either one or two semiconductor switches to control the intensity of the connected lighting load. The dimmer switch preferably includes a sensing circuit for detecting an electrical characteristic (i.e., either a voltage or a current) at a terminal of the dimmer to determine the state of the connected three-way switch(s) or four-way switch.

Abstract: A dimmer switch adapted to be coupled to a circuit including a 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 for conducting a load current through the load; 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 first controllably conductive device electrically coupled between the first and second load terminals, such that the first contro

Abstract: A lighting control device adapted to be coupled to a circuit including an AC power source, an electrical 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 lighting control device 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 coupled to the first, second, and third load terminals to conduct a load current from the AC power source to

Abstract: A smart dimmer switch for control of a lighting load from an AC voltage source can replace any switch in a three-way or four-way lighting control system. The smart dimmer switch can be connected on the line-side or the load-side of a three-way system with a standard three-way switch in the other location. Further, the dimmer switch can replace a four-way switch in a four-way system and is operable to be coupled to two standard three-way switches. The dimmer switch includes either one or two semiconductor switches to control the intensity of the connected lighting load. The dimmer switch preferably includes a sensing circuit for detecting an electrical characteristic (i.e., either a voltage or a current) at a terminal of the dimmer to determine the state of the connected three-way switch(s) or four-way switch.