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

• US 20140265880A1
• Filed: 03/14/2013
• Published: 09/18/2014
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: Lutron Technology Company LLC
• Original Assignee: Lutron Electronics Company Incorporated (Lutron Electronics)
• Inventors: Bhat, Akshay, Gredler, Timothy P., Taipale, Mark
• Granted Patent: US 9,392,675 B2
• Time in Patent Office: Days
• US Class Current: 315/158
• 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 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.

2. 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.

3. The load control system of claim 2, wherein a controller voltage is generated across the controller, the power device operable 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.

4. The load control system of claim 3, wherein the reverse digital message comprises a number of sequential data patterns, the controller operable 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, and to render the controllably conductive device 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 before the second time in the second half-cycle, the power device operable to adjust the magnitude of the controller voltage during the window time period to transmit the bit of the reverse digital message.

5. The load control system of claim 4, wherein the window time period begins approximately a half-cycle time period after the predetermined reference edge time during the first half-cycle.

9. The load control system of claim 3, 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.

17. The load control system of claim 3, 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.

18. The load control system of claim 17, 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.

19. The load control system of claim 17, 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.

41. 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.

42. The load control system of claim 41, wherein the reverse digital message is split up into a number of packets.

43. The load control system of claim 42, wherein the controller is operable to transmit a continuation pattern between the packets.

44. The load control system of claim 43, 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.

45. The load control system of claim 43, 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.

46. The load control system of claim 42, wherein each packet of the reverse digital message includes an equal number of bits of the reverse digital message.

77. The load control system of claim 1, 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.

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

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

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

6-8. -8. (canceled)

10-16. -16. (canceled)

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78-80. -80. (canceled)

82. (canceled)

85. (canceled)

86. 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 is operable 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;

wherein the control circuit is operatively coupled to the reverse receiving circuit for receiving a reverse digital message from the power device via the power wiring.

87. The controller of claim 86, wherein a controller voltage is generated across the reverse receiving circuit, the control circuit operable to receive a bit of the reverse digital message by monitoring the magnitude of the controller voltage prior to rendering the controllably conductive device conductive during a half-cycle of the AC power source.

88. The controller of claim 87, wherein the reverse digital message comprises a number of sequential data patterns, the control circuit operable 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, and to render the controllably conductive device 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 before the second time in the second half-cycle, the control circuit operable to monitor the magnitude of the controller voltage during the window time period to receive the bit of the reverse digital message.

89. The controller of claim 88, wherein the window time period begins approximately a half-cycle time period after the predetermined reference edge time during the first half-cycle.

90. The controller of claim 88, wherein the controller is operable to transmit a continuation pattern before the power device has transmitted the total number of bits of the reverse digital message.

91. The controller of claim 87, wherein the control circuit operable to receive the bit of the reverse digital message by determining whether the magnitude of the controller voltage is either greater than or less than a threshold voltage immediately prior to rendering the controllably conductive device conductive during the half-cycle of the AC power source.

92. The controller of claim 86, further comprising:

a current path in parallel with the controllably conductive device and operable to conductive current through the power device when the controllably conductive device is non-conductive, such that the magnitude of the phase-control voltage is approximately zero volts when the controllably conductive device is non-conductive.

112. The controller of claim 86, wherein the forward digital message includes a query and the reverse digital message includes an answer to the query from the forward digital message.

115. The controller of claim 86, wherein the reverse digital message is split up into a number of packets, the control circuit operable to transmit a continuation pattern between the packets.

116. The controller of claim 115, 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.

117. The controller of claim 86, wherein the reverse digital message includes feedback information from the power device.

118. The controller of claim 117, wherein the control circuit is operable to transmit the feedback information to an external device.

125. The controller of claim 86, wherein the controller comprises a two-wire device.

126. The controller of claim 86, further comprising:

a neutral terminal adapted to be coupled to the neutral side of the AC power source.

128. The controller of claim 86, wherein the control circuit is operable to alternately operate in a dimmer mode and a digital communication mode, the control circuit operable to render the controllably conductive device conductive each half-cycle at a phase angle that is dependent upon the desired lighting intensity when operating in the dimmer mode, the control circuit operable to transmit a forward digital message by encoding digital information for controlling the intensity of the lighting load in the timing edges of the phase-control voltage when operating in the digital communication mode.

93-111. -111. (canceled)

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119-124. -124. (canceled)

127. (canceled)

129. 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.

130. The power device of claim 129, wherein the control circuit is operable to control the reverse transmitting circuit to adjust the magnitude of a controller voltage generated across the controller.

131. The power device of claim 130, 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.

132. The power device of claim 131, 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.

136. The power device of claim 131, 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.

138. The power device of claim 136, 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.

139. The power device of claim 131, 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.

142. The power device of claim 129, 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.

143. The power device of claim 142, wherein the reverse digital message is split up into a number of packets.

144. The power device of claim 143, wherein the control circuit is operable to receive a continuation pattern transmitted by the controller between the packets.

145. The power device of claim 144, 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.

146. The power device of claim 144, 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.

147. The power device of claim 143, wherein each packet of the reverse digital message includes an equal number of bits of the reverse digital message.

152. The power device of claim 129, 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.

166. The power device of claim 129, further comprising:

an occupancy detection circuit for detecting the 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.

167. The power device of claim 129, 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.

168. The power device of claim 129, wherein the control circuit is operable to detect a 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 a 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.

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