Patent ID: 8173920

Claim:
A load control device for controlling the amount of power delivered to an electrical load from an AC power source, the load control device comprising: a base module having a bidirectional semiconductor switch adapted to be coupled in series electrical connection between the source and the load, a zero-crossing detect circuit for determining zero-crossing points of the AC power source, and a controller operatively coupled to a control input of the bidirectional semiconductor switch for rendering the bidirectional semiconductor switch conductive and non-conductive in response to the zero-crossing points of the AC power source; and a user interface module having an actuator for receiving an input and a visual display for providing feedback, the user interface module adapted to be mechanically connected to the base module, such that the controller of the base module is electrically coupled to the actuator and the visual display; wherein the user interface module is adapted to be disconnected from the base module, and the controller is operable to render the bidirectional semiconductor switch conductive and non-conductive at predetermined times relative to the zero-crossing points of the AC power source when the user interface module is both connected and disconnected from the base module.