Digital load control system providing power and communication via existing power wiring

• US 9,642,226 B2
• Filed: 11/22/2016
• Issued: 05/02/2017
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: Lutron Technology Company LLC
• Original Assignee: Lutron Electronics Company Incorporated (Lutron Electronics)
• Inventors: Taipale, Mark S., Gredler, Timothy P., Bhat, Akshay
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): Fernandez, Pedro C
• Application Number:
  US15/358,883
• Publication Number:
  US 20170079123A1
• Time in Patent Office: 161 Days
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/12 using optical feedback
• CPC Class Codes: H05B 45/37 Converter circuits
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 47/105 in response to determined parameters
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: H05B 47/13 by using passive infrared detectors
• CPC Class Codes: H05B 47/185 via power line carrier transmission
• CPC Class Codes: H05B 47/19 via wireless transmission
• CPC Class Codes: H05B 47/195 the transmission using visible or infrared light
• CPC Class Codes: H05B 47/196 characterised by user interface arrangements
• CPC Class Codes: H05B 47/1965 using handheld communication devices
• CPC Class Codes: H05B 47/197 Sound control or voice control
• CPC Class Codes: H05B 47/1985 Creation of lighting zones or scenes
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A two-way load control system comprises a power device, such as a load control device for controlling an electrical load receiving power from an AC power source, and a controller adapted to be coupled in series between the source and the power device. The load control system may be installed without requiring any additional wires to be run, and is easily configured without the need for a computer or an advanced commissioning procedure. The power device receives both power and communication over two wires. The controller generates a phase-control voltage and transmits a forward digital message to the power device by encoding digital information in timing edges of the phase-control voltage. The power device transmits a reverse digital message to the controller via the power wiring.

Claims

1. A power device for use in a load control device for controlling the power delivered from an AC power source to an electrical load in response to a controller, the power device comprising:

a forward receiving circuit adapted to be coupled to the controller via a power wiring, such that the controller is coupled in series electrical connection between the AC power source and the power device, the forward receiving circuit operable to receive a phase-control voltage from the controller via a power wiring;

a control circuit operatively coupled to the forward receiving circuit for receiving a forward digital message in response to digital information encoded in timing edges of the phase-control voltage; and

a reverse transmitting circuit adapted to be coupled to the controller via the power wiring;

wherein the control circuit is operatively coupled to the reverse transmitting circuit for transmitting a reverse digital message to the controller via the power wiring, the control circuit operable to control the reverse transmitting circuit to adjust a magnitude of a controller voltage generated across the controller; and

wherein the control circuit is operable to transmit a bit of the reverse digital message by adjusting the magnitude of the controller voltage prior to a timing edge of the phase-control voltage during a half-cycle of the AC power source;

wherein the reverse digital message comprises a number of sequential data patterns, each data pattern having a first timing edge at a predetermined reference edge time during a first half-cycle, the control circuit operable to adjust the magnitude of the controller voltage during a window time period during a second half-cycle of each data pattern to transmit the bit, the window time period beginning approximately a half-cycle time period after the predetermined reference edge time during the first half-cycle.

2. The power device of claim 1, wherein the predetermined reference edge time occurs after a zero-crossing of the first half-cycle.

3. The power device of claim 1, wherein the window time period is determine based on an offset time period from the predetermined reference edge time.

4. The power device of claim 3, wherein the offset time period is equal to one half-cycle of the AC power source.

5. The power device of claim 1, wherein the control circuit is operable to determine the half-cycle time period from the forward digital message received from the controller.

6. The power device of claim 5, wherein the reverse digital message comprises a total number of bits, the control circuit operable to cease transmitting the reverse digital message after transmitting a portion of the total number of bits of the reverse digital messages, and to subsequently receive a continuation pattern from the controller, the control circuit operable to update the half-cycle time period in response to the continuation pattern.

7. The power device of claim 1, wherein the control circuit is operable to transmit the bit of the reverse digital message by adjusting the magnitude of the controller voltage to be either greater than or less than a threshold voltage during the window time period.

8. The power device of claim 7, wherein the control circuit is operable to transmit a logic high bit to the controller by adjusting the magnitude of the controller voltage to be greater than the threshold voltage during the window time period.

9. The power device of claim 7, wherein the control circuit is operable to transmit an acknowledgement to the −

controller by adjusting the magnitude of the controller voltage to be less than the threshold voltage during the window time period.

10. The power device of claim 1, wherein the reverse transmitting circuit comprises an active load circuit operable to conduct an active load current through the controller before the timing edges each half-cycle to control the magnitude of the phase-control voltage to approximately zero volts.

11. The power device of claim 10, wherein the active load circuit comprises a current limit circuit operable to limit the magnitude of the active load current, and a voltage threshold circuit operable to disable the current limit circuit when the magnitude of the voltage across the active load circuit exceeds a voltage threshold.

12. The power device of claim 1, wherein the control circuit is operable to transmit one bit of the reverse digital message during a single half-cycle.

13. The power device of claim 1, wherein the control circuit is operable to transmit the reverse digital message to the controller in response to receiving the forward digital message from the controller.

14. The power device of claim 13, wherein the reverse digital message is split up into a number of packets.

15. The power device of claim 14, wherein the control circuit is operable to receive a continuation pattern transmitted by the controller between the packets.

16. The power device of claim 15, wherein the control circuit uses a half-cycle period when transmitting the reverse digital message to the controller, the control circuit operable to update the half-cycle time period in response to the continuation pattern.

17. The power device of claim 15, wherein the control circuit is operable to received a start pattern to begin receiving a new forward digital message rather than receiving the continuation pattern after one of the packets of the reverse digital message.

18. The power device of claim 14, wherein each packet of the reverse digital message includes an equal number of bits of the reverse digital message.

19. The power device of claim 13, wherein the forward digital message includes a query and the reverse digital message includes an answer to the query from the forward digital message.

20. The power device of claim 19, wherein the reverse digital message includes a yes or no answer to the query from the forward digital message.

21. The power device of claim 19, wherein the reverse digital message comprises multiple bits of data.

22. The power device of claim 13, wherein the reverse digital message includes feedback information from the power device.

23. The power device of claim 1, further comprising:

a load regulation circuit adapted to be coupled to the electrical load for controlling the power delivered to the load;

wherein the control circuit is coupled to the load regulation circuit for controlling the power delivered to the load in response to the forward digital message received from the controller.

24. The power device of claim 23, wherein the load regulation circuit is adapted to be coupled between the AC power source and the electrical load for controlling the power delivered to the load.

25. The power device of claim 24, wherein the electrical load comprises a lighting load.

26. The power device of claim 25, wherein the load regulation circuit comprises a dimming circuit for controlling an intensity of the lighting load.

27. The power device of claim 25, wherein the load regulation circuit comprises a switching circuit for toggling the lighting load on and off.

28. The power device of claim 25, wherein the lighting load comprises a gas-discharge lamp and the load regulation circuit comprises a dimming ballast circuit.

29. The power device of claim 25, wherein the lighting load comprises a light-emitting diode light source and the load regulation circuit comprises a light-emitting diode driver circuit.

30. The power device of claim 24, wherein the electrical load comprises an appliance and the load regulation circuit comprises a switching circuit for turning the appliance on and off.

31. The power device of claim 1, wherein the control circuit is operable to be assigned a link address in response to the forward digital message received from the controller during an addressing procedure of the load control system.

32. The power device of claim 31, wherein the control circuit is operable to receive a forward digital message including a query as to whether the power device requires the link address and to subsequently transmit a reverse digital message including a serial number of the power device to the controller.

33. The power device of claim 32, wherein the control circuit is operable to determine that another power device is transmitting a reverse digital message while the control circuit is transmitting the reverse digital message including the serial number to the controller, and to cease transmitting the reverse digital message including the serial number.

34. The power device of claim 31, wherein the control circuit is operable to be assigned to a group in response to a forward digital message received from the controller.

35. The power device of claim 34, wherein the control circuit is responsive to forward digital messages transmitted to the group to which the power device is assigned.

36. The power device of claim 31, wherein, prior to be assigned the link address, the control circuit is responsive to forward digital messages transmitted to a predetermined default group.

37. The power device of claim 1, further comprising:

an occupancy detection circuit for detecting occupancy and vacancy conditions in the space around the power device;

wherein the reverse digital messages transmitted by the power device comprise information regarding occupancy and vacancy conditions detected by the occupancy detection circuit.

38. The power device of claim 1, further comprising:

a photosensitive circuit for measuring a total light level around the power device;

wherein the reverse digital messages transmitted by the power device comprise the total light level measured by the photosensitive circuit.

39. The power device of claim 1, wherein the control circuit is operable to detect the number of sequential data patterns of the phase-control voltage, each data pattern having a first timing edge at a reference edge time during a first half-cycle and a second timing edge at a data edge time during a second subsequent half-cycle, the control circuit operable to measure an offset time period between the reference edge time and the data edge time of each data pattern, and to decode the forward digital message from the controller based on the measured offset time periods in each of the sequential data patterns, the control circuit operable to control the power delivered to the load in response to the forward digital message.

40. The power device of claim 1, wherein the forward receiving circuit comprises an edge detect circuit for detecting the timing edges of the phase-control voltage.

41. The power device of claim 1, wherein the control circuit is operable to receive new settings from the controller via one or more forward digital messages.

42. The power device of claim 1, wherein the control circuit is operable to receive new firmware from the controller via one or more forward digital messages.

43. The power device of claim 1, further comprising:

a digital communication circuit operatively coupled to the control circuit for transmitting and receiving digital messages via a digital communication link, the digital communication link comprising one of a wired or wireless communication link;

wherein the control circuit is operable to automatically determine whether to transmit and receive digital message via the digital communication circuit or via the forward receiving circuit and the reverse transmitting circuit.