DIGITAL LOAD CONTROL SYSTEM PROVIDING POWER AND COMMUNICATION VIA EXISTING POWER WIRING

• US 20170215257A1
• Filed: 04/05/2017
• Published: 07/27/2017
• 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
• Granted Patent: US 10,004,127 B2
• Time in Patent Office: 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: 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 configured to produce a phase-control voltage that is adapted to be received by the power device, the controller configured 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 configured to transmit a reverse digital message to the controller via the power wiring; and

wherein the controller is configured to transmit a short pattern prior to the power device transmitting the reverse digital message, the short pattern allowing the power device to synchronize to a line frequency of the AC power source.

2. The load control system of claim 1, wherein the power device is configured to transmit the reverse digital message to the controller via the power wiring by adjusting the magnitude of a controller voltage generated across the controller during a predetermined time window each half-cycle.

3. The load control system of claim 1, wherein the short pattern has a length less than the length of the forward digital message

4. The load control system of claim 1, wherein the short pattern comprises a continuation pattern and the reverse digital message is split up into a number of packets, and wherein the controller is configured to transmit the continuation pattern between the packets.

5. The load control system of claim 4, wherein the controller is configured 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.

6. The load control system of claim 4, wherein the power device uses a half-cycle period when transmitting the reverse digital message to the controller, the power device configured to update the half-cycle period in response to receiving the continuation pattern.

7. The load control system of claim 4, wherein the controller is configured to transmit the continuation pattern before the power device has transmitted the entirety of the reverse digital message.

8. The load control system of claim 1, wherein the short pattern comprises a retry pattern, the controller is configured to transmit the retry pattern if the reverse digital message has an error, and the power device is configured to retransmit the reverse digital message after receiving the retry pattern.

9. The load control system of claim 1, wherein the controller comprises 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

wherein a controller voltage is generated across the controller, the power device configured to transmit a bit of the reverse digital message by adjusting the magnitude of the controller voltage prior to when the controller renders the controllably conductive device conductive during a half-cycle of the AC power source.

10. The load control system of claim 9, wherein the controller is configured 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 configured 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, the beginning of the window time period being approximately one half-cycle duration after the predetermined referenced edge time, the power device configured to adjust the magnitude of the controller voltage during the window time period to transmit a bit of the reverse digital message.

11. The load control system of claim 10, wherein the power device is configured to determine the beginning of the window time period from a start pattern of the forward digital message.

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

a controllably conductive device adapted to be coupled in series electrical connection on a power wiring between the AC power source and a power device of the load control system;

a control circuit coupled to the controllably conductive device for rendering the controllably conductive device conductive each half-cycle of the AC power source to generate a phase-control voltage, the control circuit being configured to transmit a forward digital message to the power device by encoding digital information in timing edges of the phase-control voltage; and

a reverse receiving circuit coupled in parallel electrical connection with the controllably conductive device and configured to receive a reverse digital message from the power device via the power wiring;

wherein the control circuit is configured to transmit a short pattern prior to the power device transmitting the reverse digital message, the short pattern configured to synchronize the power device to a line frequency of the AC power source.

13. The controller of claim 12, wherein the controller is configured to receive the reverse digital message from the power device via the power wiring by adjusting the magnitude of a controller voltage generated across the controller during a predetermined time window each half-cycle.

15. The controller of claim 12, wherein the short pattern comprises a continuation pattern and the reverse digital message is split up into a number of packets, and wherein the controller is configured to transmit the continuation pattern between the packets.

16. The controller of claim 15, wherein the control circuit is configured 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.

18. The controller of claim 15, wherein the control circuit is configured to transmit the continuation pattern before the power device has transmitted the entirety of the reverse digital message.

19. The controller of claim 12, wherein the short pattern comprises a retry pattern, and wherein the control circuit is configured to transmit the retry pattern if the reverse digital message has an error, and retry pattern is configured to cause the power device to retransmit the reverse digital message.

20. The controller of claim 12, wherein the controller further comprises:

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

wherein a controller voltage is generated across the controller, and wherein the reverse receiving circuit is configured to receive a bit of the reverse digital message by adjusting the magnitude of the controller voltage prior to when the control circuit renders the controllably conductive device conductive during a half-cycle of the AC power source.

21. The controller of claim 20, wherein the control circuit is configured to render the controllably conductive device conductive to generate a first timing edge at a predetermined reference edge time during a first half cycle of each data pattern of the reverse digital message, wherein a window time period exists during a second half-cycle of the data pattern after a zero-crossing of the second half-cycle, a beginning of the window time period being approximately one half-cycle duration after the predetermined reference edge time;

and

wherein the control circuit is configured to monitor the magnitude of the controller voltage during the window time period to receive the bit of the reverse digital message.

23. 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 that is coupled in series electrical connection between the AC power source and the power device, the power device comprising:

a forward receiving circuit adapted to be coupled to the controller via a power wiring, and configured to receive a phase-control voltage from the controller via the power wiring;

a control circuit operatively coupled to the forward receiving circuit for receiving a forward digital message from the controller 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 configured to control the reverse transmitting circuit to adjust a magnitude of a controller voltage generated across the controller; and

wherein the control circuit is configured to receive a short pattern from the controller prior to the power device transmitting the reverse digital message, the short pattern configured to synchronize the power device to a line frequency of the AC power source.

24. The power device of claim 23, wherein the power device is configured to transmit the reverse digital message to the controller via the power wiring by adjusting the magnitude of the controller voltage generated across the controller during a predetermined time window each half-cycle.

26. The power device of claim 23, wherein the short pattern comprises a continuation pattern and the reverse digital message is split up into a number of packets, and wherein the control circuit is configured to receive the continuation pattern between transmissions of the packets of the reverse digital message.

27. The power device of claim 26, wherein the control circuit is configured to receive a start pattern to begin receiving a new forward digital message rather than receiving the continuation pattern after transmitting one of the packets of the reverse digital message.

28. The power device of claim 26, wherein the control circuit uses a half-cycle period when transmitting the reverse digital message to the controller, and wherein the control circuit is configured to update the half-cycle period in response to receiving the continuation pattern.

29. The power device of claim 26, wherein the control circuit is configured to receive the continuation pattern before the control circuit has transmitted the entirety of the reverse digital message.

30. The power device of claim 23, wherein the short pattern comprises a retry pattern, and wherein the control circuit is configured to receive the retry pattern if the reverse digital message has an error, and the control circuit is configured to retransmit the reverse digital message after receiving the retry pattern.

31. The power device of claim 23, wherein a controller voltage is generated across the controller, and wherein the reverse transmitting circuit is configured to transmit a bit of the reverse digital message by adjusting the magnitude of the controller voltage prior to when the controller renders a controllably conductive device conductive during a half-cycle of the AC power source.

32. The power device of claim 31, 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 configured 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 reverse digital message, the window time period beginning approximately a half-cycle time period after the predetermined reference edge time during the first half-cycle.

33. The power device of claim 32, wherein the control circuit is configured to determine the beginning of the window time period from a start pattern of the forward digital message.