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

• US 9,392,675 B2
• Filed: 03/14/2013
• Issued: 07/12/2016
• 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, Gredler, Timothy P., Bhat, Akshay
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): Fernandez, Pedro C
• Application Number:
  US13/828,920
• Publication Number:
  US 20140265880A1
• Time in Patent Office: 1,216 Days
• US Class Current: 1/1
• 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: 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 load control system comprising:

a power device adapted to receive power from an AC power source via a power wiring; and

a controller adapted to be coupled in series electrical connection on the power wiring between the AC power source and the power device, the controller operable to produce a phase-control voltage that is adapted to be received by the power device, the controller comprising a controllably conductive device adapted to be coupled in series electrical connection between the AC power source and the power device for generating the phase-control voltage, and the controller operable to transmit a forward digital message to the power device by encoding digital information in timing edges of the phase-control voltage;

wherein the power device is operable to transmit a reverse digital message to the controller via the power wiring by adjusting a magnitude of a controller voltage generated across the controller prior to when the controller renders the controllably conductive device conductive during half-cycles of the AC power source;

wherein the controller is operable to render the controllably conductive device conductive to generate a timing edge at a predetermined reference edge time during a first half cycle of a data pattern of the reverse digital message; and

wherein the power device is operable to determine a beginning of a window time period that exists during a second half-cycle of the data pattern after a zero-crossing of the second half-cycle, wherein a beginning of the window time period is approximately one half-cycle duration after the predetermined referenced edge time, the power device operable to adjust the magnitude of the controller voltage during the window time period to transmit a bit of the reverse digital message.

2. The load control system of claim 1, wherein the controller is operable to render the controllably conductive device conductive at a second time during the second half-cycle of the data pattern of the reverse digital message, such that the window time period begins after the zero-crossing of the second half-cycle and before the second time in the second half-cycle.

3. The load control system of claim 2, wherein the window time period is determine based on an offset time period from the predetermined reference edge time.

4. The load control system of claim 3, wherein the offset time period is equal to one half-cycle of the AC power source, and the window time period begins approximately one half-cycle from the predetermined reference edge time and ends at the second time.

5. The load control system of claim 1, wherein a power supply of the controller is operable to charge when the controllably conductive device is non-conductive from the zero-crossing of the second half-cycle to one half-cycle from the predetermined reference edge.

6. The load control system of claim 1, wherein the controller comprises a current path in parallel with the controllably conductive device and the power device comprises an active load circuit for conducting an active load current through the current path when the controllably conductive device is non-conductive to control the magnitude of the phase-control voltage to approximately zero volts.

7. The load control system of claim 1, wherein the power device 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 load control system of claim 7, wherein the power device 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 load control system of claim 7, wherein the power device 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 load control system of claim 1, wherein the power device is operable to transmit the reverse digital message to the controller in response to receiving the forward digital message from the controller.

11. The load control system of claim 10, wherein the reverse digital message is split up into a number of packets.

12. The load control system of claim 11, wherein the controller is operable to transmit a continuation pattern between the packets.

13. The load control system of claim 12, wherein the power device uses a half-cycle period when transmitting the reverse digital message to the controller, the power device operable to update the half-cycle time period in response to the continuation pattern.

14. The load control system of claim 12, wherein the controller is operable to transmit a start pattern to begin transmitting a new forward digital message rather than transmitting the continuation pattern after one of the packets of the reverse digital message.

15. The load control system of claim 11, wherein each packet of the reverse digital message includes an equal number of bits of the reverse digital message.

16. The load control system of claim 1, wherein the controller voltage is generated across the controller, the power device operable to transmit the reverse digital message to the controller by encoding digital information in the controller voltage.

17. The load control system of claim 1, wherein the load control system is configured without accessing the power device or an electrical load.

18. The load control system of claim 1, wherein the controller comprises a two-wire device.

19. The load control system of claim 1, wherein the controller has a direct connection to the neutral side of the AC power source.

20. A load control system comprising:

a power device adapted to receive power from an AC power source via a power wiring; and

a controller adapted to be coupled in series electrical connection on the power wiring between the AC power source and the power device, the controller operable to produce a phase-control voltage that is adapted to be received by the power device, the controller comprising a controllably conductive device adapted to be coupled in series electrical connection between the AC power source and the power device for generating the phase-control voltage, and the controller operable to transmit a forward digital message to the power device by encoding digital information in timing edges of the phase-control voltage;

wherein the power device is operable to transmit a reverse digital message to the controller via the power wiring by adjusting a magnitude of a controller voltage generated across the controller prior to when the controller renders the controllably conductive device conductive during half-cycles of the AC power source;

wherein the controller is operable to render the controllably conductive device conductive to generate a timing edge at a predetermined reference edge time during a first half cycle of each data pattern of the reverse digital message, and to render the controllably conductive device conductive at a second time during a second half-cycle of each data pattern of the reverse digital message, such that a window time period exists after a zero-crossing of the second half-cycle and before the second time in the second half-cycle, the second time more than a duration of a half-cycle of the AC power source away from the predetermined reference edge time; and

wherein the power device is operable to adjust the magnitude of the controller voltage during the window time period to transmit a bit of the reverse digital message.

21. The load control system of claim 20, wherein the window time period is determined based on an offset time period from the predetermined reference edge time.

22. The load control system of claim 21, wherein the offset time period is equal to one half-cycle of the AC power source, and the window time period begins one half-cycle after the predetermined reference edge time and ends at the second time.

23. The load control system of claim 20, wherein the controller comprises a two-wire device.

24. The load control system of claim 20, wherein the controller has a direct connection to the neutral side of the AC power source.

25. The load control system of claim 20, wherein the controller comprises a current path in parallel with the controllably conductive device and the power device comprises an active load circuit for conducting an active load current through the current path when the controllably conductive device is non-conductive to control the magnitude of the phase-control voltage to approximately zero volts.

26. The load control system of claim 20, wherein the power device 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.

27. The load control system of claim 26, wherein the power device 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.

28. The load control system of claim 26, wherein the power device 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.

29. The load control system of claim 26, wherein the power device is operable to transmit the reverse digital message to the controller in response to receiving the forward digital message from the controller.

30. The load control system of claim 29, wherein the reverse digital message is split up into a number of packets.

31. The load control system of claim 30, wherein the controller is operable to transmit a continuation pattern between the packets.

32. The load control system of claim 31, wherein the power device uses a half-cycle period when transmitting the reverse digital message to the controller, the power device operable to update the half-cycle time period in response to the continuation pattern.

33. The load control system of claim 31, wherein the controller is operable to transmit a start pattern to begin transmitting a new forward digital message rather than transmitting the continuation pattern after one of the packets of the reverse digital message.

34. The load control system of claim 30, wherein each packet of the reverse digital message includes an equal number of bits of the reverse digital message.

35. The load control system of claim 20, wherein a controller voltage is generated across the controller, the power device operable to transmit the reverse digital message to the controller by encoding digital information in the controller voltage.

36. The load control system of claim 20, wherein the load control system is configured without accessing the power device or an electrical load.