Multiple location load control system

Patent metadata

Field	Value
Publication number	US-9699863-B2
Application number	US-201514720701-A
Country	US
Kind code	B2
Filing date	May 22, 2015
Priority date	May 30, 2014
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A multiple location load control system comprises a main device and remote devices, which do not require neutral connections, but allow for visual and audible feedback at the main device and the remote devices. The main device and the remote devices are adapted to be coupled together via an accessory wiring. The main device can be wired on the line side and the load side of the load control system. The main device is configured to enable a charging path to allow the remote devices to charge power supplies through the accessory wiring during a first time period of a half-cycle of the AC power source. The main device and the remote devices are configured to communicate with each other via the accessory wiring during a second time period of the half-cycle, for example, by actively pulling-up and actively pulling-down the accessory wiring to communicate using tri-state logic.

First claim

What is claimed is:

1. A multiple location load control system for controlling an amount of power delivered to an electrical load from an AC power source, the load control system comprising:
a main load control device comprising a first main terminal, a second main terminal, and an accessory terminal, the main load control device adapted to be coupled in series electrical connection between the AC power source and the electrical load for control of the amount of power delivered to the electrical load, the main load control device configured to conduct a load current from the AC power source to the electrical load via the first and second main terminals; and
a remote load control device adapted to be coupled between the first main terminal and the accessory terminal of the main load control device or between the second main terminal and the accessory terminal of the main load control device, the remote load control device adapted to be coupled to the accessory terminal of the main load control device via an accessory wiring, the remote load control device comprising a power supply;
wherein the main load control device is configured to control the accessory wiring using tri-state logic, the main load control device configured to enable a charging path to allow the power supply of the remote load control device to charge through the accessory wiring 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 configured to communicate with each other via the accessory wiring during a second time period of the half-cycle of the AC power source;
wherein the main load control device comprises a first switching circuit operably coupled between the AC power source and the accessory wiring for conducting a charging current from the AC power source to the power supply of the remote load control device; and
wherein the main load control device further comprises a second switching circuit operably coupled between the accessory wiring and a circuit common.

2. The load control system of claim 1 , wherein the main load control device further comprises a control circuit coupled to the first and second switching circuits for rendering the first and second switching circuits conductive and non-conductive.

3. The load control system of claim 2 , wherein the control circuit is configured to render the first and second switching circuits conductive and non-conductive on a complementary basis to transmit a digital message via the accessory wiring during the second time period.

4. The load control system of claim 3 , wherein the control circuit is configured to render the first switching circuit conductive and the second switching circuit non-conductive in an active pull-up state to transmit a first bit during the second time period, and to render the first switching circuit non-conductive and the second switching circuit conductive in an active pull-down state to transmit a first second during the second time period.

5. The load control system of claim 4 , wherein the control circuit is configured to render the first and second switching circuits non-conductive to generate a high impedance state on the accessory wiring.

6. The load control system of claim 5 , wherein the control circuit is configured to render the first and second switching circuits non-conductive in the high impedance state outside of the first and second periods of the half-cycle of the AC power source.

7. The load control system of claim 2 , wherein the control circuit is configured to render the first switching circuit conductive and the second switching circuit non-conductive to enable the charging path to allow the power supply of the remote load control device to charge through the accessory wiring during the first time period.

8. The load control system of claim 7 , wherein the control circuit is configured to render the first switching circuit conductive and the second switching circuit non-conductive such that the first time period starts immediately following a zero-crossing at the beginning of the half-cycle of the AC power source.

9. The load control system of claim 8 , wherein the remote load control device is configured to detect the start of the first time period for determining when the second time period will occur to receive a digital message transmitted by the main load control device.

10. The load control system of claim 2 , wherein the main load control device further comprises an energy storage device configured to charge from the AC power source, the first switching circuit coupled between the energy storage device.

11. The load control system of claim 10 , wherein the energy storage device comprises a capacitor.

12. The load control system of claim 1 , wherein the main load control device and the remote load control device are configured to transmit and receive digital messages via the accessory wiring during the second time period of the half-cycle.

13. The load control system of claim 12 , wherein the digital messages comprise a command to control the amount of power delivered to the electrical load.

14. The load control system of claim 12 , wherein the digital messages comprise an amount of power presently being delivered to the electrical load.

15. The load control system of claim 1 , wherein the first time period occurs before the second time period each half-cycle.

16. The load control system of claim 1 , wherein the main load control device and the remote control device form a communication path that does not pass through either the AC power source or the electrical load.

17. The load control system of claim 1 , wherein the main load control device is adapted to be located on either the line-side or the load-side of the load control system.

18. The load control system of claim 1 , wherein the main load control device is adapted to communication using tri-state logic by actively pulling up the accessory wiring and actively pulling down the accessory wiring.

19. The load control system of claim 1 , wherein the charging path is via the accessory wiring and a communication circuit of the remote load control device to the power supply of the remote load control device.

20. A communication circuit for transmitting signals from a first control device to a second control device over an electrical wire, the communication circuit comprising:
a first switching circuit adapted to be coupled between an AC power source and the electrical wire, the first switching circuit configured to conduct a charging current for a power supply of the second control device through the electrical wire during a first time period of the half-cycle of an AC power source; and
a second switching circuit adapted to be coupled between the electrical wire and a circuit common, the first and second switching circuits rendered conductive and non-conductive on a complementary basis to transmit a digital message to the second control device via the electrical wire during a second time period of the half-cycle of the AC power source;
wherein the first and second switching circuits are configured to be rendered non-conductive to generate a high impedance state on the electrical wire outside of the first and second periods of the half-cycle of the AC power source; and
wherein the first switching circuit is rendered conductive and the second switching circuit is rendered non-conductive in an active pull-up state to transmit a first bit during the second time period.

21. The communication circuit of claim

Assignees

• Lutron Electronics Co

Inventors

• Weightman Russell
• Lenz Jonathan T
• Shukla Jaykrishna A
• Raneri Daniel Curtis

Classifications

• G11C7/04

  with means for avoiding disturbances due to temperature effects · CPC title

• G11C7/24

  Memory cell safety or protection circuits, e.g. arrangements for preventing inadvertent reading or writing; Status cells; Test cells · CPC title

• G11C29/12

  Built-in arrangements for testing, e.g. built-in self testing [BIST] {or interconnection details} · CPC title

• H05B39/04

  Controlling · CPC title

• G11C5/025

  Geometric lay-out considerations of storage- and peripheral-blocks in a semiconductor storage device (geometrical lay-out of the components in integrated circuits, geometrical lay-out of the components in integrated circuits H10D89/10) · CPC title