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

摘要

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.

主权项

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.