Load control device having a compact antenna

• US 7,834,817 B2
• Filed: 06/24/2009
• Issued: 11/16/2010
• Est. Priority Date: 06/06/2005
• Status: Active Grant

• Current Assignee: Lutron Technology Company LLC
• Original Assignee: Lutron Electronics Company Incorporated (Lutron Electronics)
• Inventors: Bollinger, Robert Jr., Altonen, Gregory, Mosebrook, Donald R.
• Primary Examiner(s): Owens; Douglas W
• Assistant Examiner(s): DUONG, DIEU HIEN
• Application Number:
  US12/490,628
• Publication Number:
  US 20090256484A1
• Time in Patent Office: 510 Days
• Field of Search: 343/866, 343/867, 343/895, 315/291, 315/154
• US Class Current: 343/867
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 7/005 with variable reactance for tuning the antenna

Abstract

A load control device for controlling the power delivered to an electrical load has a power switch, a transmitter and/or a receiver in communication with a controller for the switch; a mounting yoke for a traditional style faceplate; an actuator button extending through an opening of the faceplate; an antenna receiving a first signal from a remote control device and/or transmitting a second signal to a remote control device, the receiver coupling the first signal from the antenna to the controller for controlling the switch, the transmitter coupling the second signal from the controller to the antenna. The antenna has a printed circuit board disposed perpendicular to the yoke; first and second magnetically coupled conductive loops; the antenna disposed inside and behind the actuator button and extending through and beyond the opening of the faceplate.

Claims

1. A load control device for controlling the power delivered to an electrical load, the load control device comprising:

a controllably conductive device for controlling the power delivered to the electrical load, the controllably conductive device having a control input;

a controller coupled to the control input of the controllably conductive device for control of the controllably conductive device;

a transmitter and/or a receiver in communication with the controller;

a substantially-planar mounting yoke adapted to receive a traditional-style faceplate mounted thereto;

an actuator button for providing an input to the controller, the actuator button mounted relative to the yoke, such that the actuator button is adapted to extend through an opening of the traditional-style faceplate when the faceplate is attached to the yoke; and

an antenna coupled to the transmitter and/or receiver, the antenna adapted to receive a first signal at a specified frequency from a remote control device and/or transmit a second signal at a specified frequency to a remote control device, the receiver operable to couple the first signal from the antenna to the controller for remotely controlling the controllably conductive device, and/or the transmitter operable to couple the second signal from the controller to the antenna, the antenna comprising;

a printed circuit board having first and second sides disposed in a plane perpendicular to the mounting yoke;

a first loop of conductive material having a capacitance and an inductance, the capacitance and the inductance forming a circuit resonant at the specified frequency, the first loop formed on the first side of the printed circuit board; and

a second loop of conductive material having two ends adapted to be electrically coupled to the transmitter and/or receiver, the second loop formed on one of the sides of the printed circuit board and magnetically coupled to the first loop;

wherein the antenna is positioned inside and behind the actuator button and is adapted to extend through the opening of the faceplate beyond the front surface of the faceplate when the faceplate is attached to the mounting yoke.

2. The load control device of claim 1, wherein the electrical load comprises a lighting load and the load control device comprises a dimmer switch.

3. The load control device of claim 2, further comprising:

a backcover connected to the yoke to enclose the controllably conductive device, the controller, and the transmitter and/or receiver; and

a dimmer printed circuit board enclosed by the yoke and the backcover, the controllably conductive device, the controller, and the transmitter and/or receiver mounted to the dimmer printed circuit board, the antenna printed circuit board connected to the dimmer printed circuit board, such that the antenna printed circuit board is disposed in a plane perpendicular to the dimmer printed circuit board.

4. The load control device of claim 3, wherein the antenna printed circuit board comprises terminals connected to the dimmer printed circuit board.

5. The load control device of claim 4, wherein the first loop of conductive material is connected to a circuit common of the dimmer printed circuit board via at least one of the terminals, and the second loop of conductive material is connected to the transmitter and/or receiver via another one of the terminals.

6. The load control device of claim 1, wherein the first loop of conductive material intersects with the second loop of conductive material.

7. The load control device of claim 6, wherein the second loop of conductive material is formed on the first side of the antenna printed circuit board.

8. The load control device of claim 7, wherein the antenna comprises a trace of conductive material provided on the second side of the antenna printed circuit board, the trace electrically connected to the first loop of conductive material on the first side of the antenna printed circuit board through a plurality of vias.

9. The load control device of claim 1, wherein the second loop is only magnetically coupled to the first loop and electrically insulated from the first loop.

10. The load control device of claim 9, wherein the second loop of conductive material is formed on the second side of the printed circuit board.

11. The load control device of claim 1, wherein the first loop of conductive material comprises a break and the capacitance of the first loop comprises a capacitor provided across the break.

12. The load control device of claim 1, wherein a first current flows in the first loop of conductive material when a second current flows through the second loop of conductive material, the first current having a magnitude larger than the magnitude of the second current.

13. The load control device of claim 1, wherein the faceplate comprises a metal faceplate.