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

Patent metadata

Field	Value
Publication number	US-9736911-B2
Application number	US-201213359722-A
Country	US
Kind code	B2
Filing date	Jan 27, 2012
Priority date	Jan 17, 2012
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A load control system comprises 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 load control 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 load control device receives both power and communication over two wires, and the controller generates a phase-control voltage that has at least one timing edge in each half-cycle, and transmits digital messages by modulating a timing edge of the phase-control voltage relative to a reference edge. The controller may be operable to receive inputs from a plurality of different input devices, and the load control device may be operable to control a plurality of different loads.

First claim

What is claimed is:

1. A load control system for controlling an electrical load receiving power from an AC power source, the load control system comprising:
a load control device for controlling the electrical load; and
a controller adapted to be coupled in series electrical connection between the AC power source and the load control device to conduct a load current from the AC power source to the electrical load, the controller operable to produce a phase-control voltage is adapted to be received by the load control device, wherein the phase-control voltage comprises an AC voltage that is characterized by a conduction period for a portion of each half-cycle;
wherein the controller is operable to transmit a digital message to the load control device for controlling the load by encoding digital information in timing edges of the phase-control voltage, the phase-control voltage having at least one timing edge in each half-cycle of the AC power source when the controller is transmitting the digital message to the load control device.

2. The load control system of claim 1 , wherein the phase-control voltage produced by the controller has 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 and a second timing edge at a data edge time during a second subsequent half-cycle, such that an offset time period exists between the reference edge time and the data edge time of each data pattern, the controller operable to transmit the digital message to the load control device by controlling the offset time period in each of the sequential data patterns.

3. The load control system of claim 2 , wherein the controller is operable to transmit the digital message to the load control device by adjusting the offset time period between the reference edge time during the first half-cycle and the data edge time during the second half-cycle to be one of a plurality of possible predetermined offset time periods.

4. The load control system of claim 3 , wherein the controller is operable to transmit the digital message to the load control device by adjusting the offset time period of each data pattern to one of four possible predetermined offset time periods.

5. The load control system of claim 4 , wherein the controller is operable to control each data pattern of the phase-control voltage to have a third timing edge at a data edge time during a third half-cycle immediately following the second half-cycle, such that a second offset time period exists between the reference edge time during the first half-cycle and the data edge time during the third half-cycle.

6. The load control system of claim 5 , wherein the second offset time period between the reference edge time during the first half-cycle and the data edge time during the third half-cycle may be controlled to one of four possible predetermined offset time periods.

7. The load control system of claim 6 , wherein the controller is operable to transmit four bits of data per 1.5 line cycles.

8. The load control system of claim 4 , wherein the controller is operable to control the phase-control voltage to have a third timing edge at a second reference edge time during a third half-cycle immediately following the second half-cycle and to have a fourth timing edge at a second data edge time during a fourth subsequent half-cycle, such that a second offset time period exists between the second reference edge time and the second data edge time.

9. The load control system of claim 8 , wherein the controller is operable to transmit two bits of data per line cycle.

10. The load control system of claim 3 , wherein the controller is operable to transmit the digital message to the load control device over a predetermined number of consecutive line cycles.

11. The load control system of claim 10 , wherein the controller is operable to transmit a start symbol to begin transmitting a digital message by controlling the phase-control voltage to have a third timing edge at a first start symbol edge time during a third half-cycle and a fourth timing edge at a second start symbol edge time during a fourth subsequent half-cycle, such that a start symbol offset time period exists between the first start symbol edge time and the second start symbol edge time, the third and fourth half-cycles occurring before the first and second half-cycles, the start symbol offset time period not being equal to any of the possible offset time periods that may exist between the reference edge time during the first half-cycle and the data edge time during the second half-cycle.

12. The load control system of claim 11 , wherein the start symbol offset time period is longer than the possible offset time periods that may exist between the reference edge time during the first half-cycle and the data edge time during the second half-cycle.

13. The load control system of claim 11 , wherein the controller is operable to interrupt a first digital message that is being transmitted in order to transmit a second digital message to the load control devices by transmitting the start symbol before the end of the first digital message.

14. The load control system of claim 2 , wherein the digital message transmitted by the controller comprises a predetermined number of bits, such that the digital message is transmitted to the load control device over a predetermined number of consecutive line cycles.

15. The load control system of claim 14 , wherein the digital message transmitted by the controller indicates a control channel, the load control device operable to decide whether to respond to the digital message or not in response to the control channel of the digital message.

16. The load control system of claim 15 , wherein the digital message transmitted by the controller further comprises command data and a command type specifying how the load control device should respond to the command data.

17. The load control system of claim 16 , wherein the digital message transmitted by the controller further comprises a predetermined number of error detect bits to allow the load control device to determine if an error occurred during transmission and reception of the digital message.

18. The load control system of claim 17 , wherein the digital message transmitted by the controller further comprises a start symbol at the beginning.

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

20. The load control system of claim 19 , wherein the controller comprises a controllably conductive device adapted to be coupled in series electrical connection between the AC power source and the electrical load for generating the phase-control voltage.

21. The load control system of claim 20 , wherein the controller comprises a power supply coupled in parallel electrical connection with the controllably conductive device for conducting a charging current when the controllably conductive device is non-conductive to generate a DC supply voltage.

22. The load control system of claim 21 , further comprising:
an active load circuit coupled in parallel electrical connection with the load control device for providing a path for the charging current of the power supply of the controller, the active load circuit operable to conduct an active load current having a magnitude approximately equal to the magnitude of the charging current of the power supply of the controller when the controllably conductive device is non-conducti

Assignees

• Taipale Mark S
• Steiner James P
• Zaharchuk Walter S
• Pessina Michael W
• Spira Joel S
• Lutron Electronics Co

Inventors

• Taipale Mark S
• Steiner James P
• Zaharchuk Walter S
• Pessina Michael W
• Spira Joel S

Classifications

• H05B45/10

  Controlling the intensity of the light · CPC title

• H05B47/11 Primary

  by determining the brightness or colour temperature of ambient light · CPC title

• H05B47/185 Primary

  via power line carrier transmission · CPC title

• H05B37/0272

  Electricity · mapped topic

• H05B33/0845

  Electricity · mapped topic