Multiple Location Load Control System

A load control system for controlling power delivered to an electrical load from an AC power source, the system comprising:

• a main load control device comprising a first load terminal, a second load terminal, and an accessory terminal, the main load control device further comprising a bidirectional semiconductor switch adapted to be electrically coupled in series between the AC power source and the electrical load for controlling the 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 load terminals, the main load control device comprising a receiver for receiving digital messages, the main load control device configured to control the amount of power delivered to the electrical load in response to the received digital messages;
• and
• a remote load control device adapted to be coupled between the first load terminal and the accessory terminal of the main load control device or between the second load terminal and the accessory terminal of the main load control device, the remote load control device comprising a power supply configured to charge from the AC power source through the main load control device during a first time period of a half-cycle of the AC power source, the remote load control device further comprising a transmitter for transmitting digital messages;
• wherein the receiver of the main load control device and the transmitter of the remote load control device are coupled together so as to form a communication path, the transmitter of the remote load control device configured to transmit at least a portion of a digital message to the receiver of the main load control device during a second time period of the half-cycle.

A load control system for controlling power delivered to an electrical load from an AC power source, the system comprising:

• a main load control device for controlling the electrical load, the main load control device comprising a first load terminal, a second load terminal, and an accessory terminal, 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 load terminals, the main load control device comprising a receiver configured to receive digital messages to allow the main load control device to control the electrical load in response to the received digital messages;
• and
• a remote load control device adapted to be coupled between the first load terminal and the accessory terminal of the main load control device or between the second load terminal and the accessory terminal of the main load control device, the remote load control device comprising a power supply configured to charge from the AC power source through the main load control device during a first time period of a half-cycle of the AC power source, the remote load control device further comprising a transmitter for transmitting digital messages;
• wherein the transmitter of the remote load control device and the receiver of the main load control device are coupled together such that the transmitter of the remote load control device is configured to transmit at least a portion of a digital message to the receiver of the main load control device during a second time period of the half-cycle.