Load control system providing power and communication over AC line wiring

• US 9,301,371 B2
• Filed: 07/11/2014
• Issued: 03/29/2016
• Est. Priority Date: 04/23/2007
• Status: Active Grant

• Current Assignee: Lutron Technology Company LLC
• Original Assignee: Lutron Electronics Company Incorporated (Lutron Electronics)
• Inventors: Steiner, James P., Baby, Cyril, Buck, Christopher, Carmen, Daniel F.
• Primary Examiner(s): Vu, Jimmy
• Application Number:
  US14/329,145
• Publication Number:
  US 20140320038A1
• Time in Patent Office: 627 Days
• Field of Search: 315/301, 315/302, 315/299, 315/307, 315/308, 315/291, 315/294, 315/360, 315/224, 315/362, 315/295, 315/297
• US Class Current: 1/1
• CPC Class Codes: H05B 39/041 the light-intensity of the source H05B39/08 takes precedence
• CPC Class Codes: H05B 39/044 continuously H05B39/042 takes precedence
• CPC Class Codes: H05B 47/165 following a pre-assigned programmed sequence; Logic control [LC]
• CPC Class Codes: H05B 47/175 by remote control
• CPC Class Codes: H05B 47/18 via data-bus transmission
• CPC Class Codes: H05B 47/185 via power line carrier transmission
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A load control system comprises a main load control device and a remote load control device, which does not require a neutral connection and allows for feedback at the remote load control device. The main device and the remote load control device are adapted to be coupled between an AC power source and an electrical load. The main load control device comprises a load control circuit for controlling the amount of power delivered to the electrical load. The main load control device is operable to enable a charging path to allow the remote load control device to charge a power supply during a first time period of a half-cycle of the AC power source. The main load control device and the remote load control device are operable to communicate with each other during a second time period of the half-cycle.

Claims

1. A load control system for controlling the power delivered to an electrical load from an AC power source, the system comprising:

a main load control device for controlling the electrical load, the main load control device operable to conduct an AC current from the AC power source, the main load control device comprising a load control circuit for controlling the amount of power delivered to the electrical load, the main load control device further comprising a receiver for receiving digital messages, such that the main load control device is able to control the electrical load in response to the received digital messages; and

a remote load control device configured to be coupled in series electrical connection with the main load control device for conducting the AC current from the AC power source, the remote load control device comprising a power supply configured to charge from the AC power source through the main load control device during a first time period of a present half-cycle of the AC power source, the power supply configured to charge during time periods in subsequent half-cycles that occur at approximately the same time during the respective half-cycle as the first time period occurs during the present half-cycle, the remote load control device further comprising a transmitter for transmitting digital messages;

wherein the remote load control device is configured to be coupled in series electrical connection between the AC power source and the main load control device; and

wherein the transmitter of the remote load control device and the receiver of the main load control device are coupled together such that the transmitter of the remote load control device is able to transmit at least a portion of a digital message to the receiver of the main load control device during a second time period of the present half-cycle, the transmitter of the remote load control device configured to transmit at least a portion of a digital message to the receiver of the main load control device during time periods in subsequent half-cycles that occur at approximately the same time during the respective half-cycle as the second time period occurs during the present half-cycle.

2. The load control system of claim 1, wherein the transmitter of the remote load control device and the receiver of the main load control device are coupled together so as to form a communication path during the second time period of the present half-cycle.

3. The load control system of claim 2, wherein the main load control device comprises a switching circuit that is rendered conductive to form the communication path between the receiver of the main load control device and the transmitter of the remote load control device during the second time period of the present half-cycle.

4. The load control system of claim 2, wherein the communication path formed by the main load control device and the remote control device does not pass through the electrical load.

5. The load control system of claim 2, wherein the communication path formed by the main load control device and the remote control device does not pass through the AC power source.

6. The load control system of claim 1, wherein the remote load control device is configured to be coupled in series electrical connection with the main load control device between the AC power source and the electrical load.

7. The load control system of claim 6, wherein the remote load control device is configured to be coupled to the main load control device through an accessory wiring, such that the transmitter of the remote load control device is able to transmit digital messages to the receiver of the main load device via the accessory wiring during the second time period.

8. The load control system of claim 7, wherein the main load control device generates a supply voltage and provides the supply voltage on the accessory wiring to allow the remote load control device to charge the power supply.

9. The load control system of claim 1, wherein the transmitter of the remote load control device is configured to transmit a single digital message to the receiver of the main load control device over multiple half-cycles, such that the transmitter transmits a predetermined number of bits of the single digital message during each of the multiple half-cycles.

10. The load control system of claim 9, wherein the remote load control device comprises an actuator for receiving a user input, the transmitter configured to transmit the single digital message over the multiple half-cycles in response to an actuation of the actuator.

11. The load control system of claim 1, wherein the main load control device and the remote load control device both comprise transceivers, such that the main load control device and the remote load control device are able to communicate with each other.

12. The load control system of claim 1, wherein the second time period occurs after the first time period during the present half-cycle.

13. The load control system of claim 1, wherein the load control circuit conducts the AC current through the electrical load.

14. A load control device for controlling the power delivered to an electrical load from an AC power source, the load control device configured for use in a load control system including a remote control device having a power supply and a transmitter, the load control device comprising:

a load control circuit configured to be coupled to the electrical load for controlling the power delivered to the electrical load;

a controller operatively coupled to the load control circuit for controlling the power delivered to the electrical load;

a switching circuit configured to be rendered conductive by the controller to allow the power supply of the remote control device to draw current in order to charge during a first time period of a half-cycle of the AC power source, the controller configured to render the switching circuit conductive to allow the power supply of the remote control device to draw current to charge during time periods in subsequent half-cycles that occur at approximately the same time during the respective half-cycle as the first time period occurs during the present half-cycle; and

a communication circuit coupled to the controller for receiving digital messages, the communication circuit configured to be coupled to the transmitter of the remote control device such that the controller is configured to receive at least a portion of a digital message from the transmitter of the remote load control device during a second time period of the half-cycle, the controller configured to receive at least a portion of a digital message from the transmitter of the remote load control device during time periods in subsequent half-cycles that occur at approximately the same time during the respective half-cycle as the second time period occurs during the present half-cycle.

15. The load control device of claim 14, wherein the communication circuit is configured to be coupled to the transmitter of the remote control device so as to form a communication path during a second time period of the half-cycle.

16. The load control device of claim 15, wherein the controller is configured to render the switching circuit conductive during the second time period to form the communication path.

17. The load control device of claim 14, wherein the load control circuit comprises a bidirectional semiconductor switch having a control input, the controller coupled to the control input of the bidirectional semiconductor switch for rendering the bidirectional semiconductor switch conductive.

18. The load control device of claim 14, further comprising:

an accessory terminal configured to be coupled to the remote control device, the switching circuit coupled to the accessory terminal for allowing the power supply of the remote control device to draw current through the accessory terminal, the communication circuit coupled to the accessory terminal for receiving digital messages from the transmitter of the remote control device; and

a power supply for generating a supply voltage, the power supply having an output operatively coupled to the accessory terminal, such that the supply voltage is provided at the accessory terminal during the first time period.

19. The load control device of claim 14, wherein the communication circuit is configured to receive a single digital message from the transmitter of the remote control device over multiple half-cycles, such that the communication circuit receives predetermined number of bits of the digital message during each of the multiple half-cycles.

20. The load control device of claim 14, wherein at least one of the digital messages comprises a command to control the amount of power delivered to the load.

21. The load control device of claim 14, wherein the second time period occurs after the first time period during the present half-cycle.

22. The load control device of claim 14, wherein the communication circuit comprises a receiver.