Patent ID: 8242714
Filing Date: 2012-08-14
Classification: H05B,Y02B,Y10S

Abstract:
1. A dimmer switch adapted to be coupled between an AC power source generating an AC line voltage and a lighting load, the dimmer switch controlling the intensity of the lighting load within a dynamic range bounded by a high-end intensity setting and a low-end intensity setting, the dimmer switch comprising: a controllably conductive switching device adapted to be coupled in series electrical connection between the AC power source and the lighting load, the controllably conductive switching device controlling the amount of power delivered to the lighting load, the controllably conductive switching device having a conductive state and a non-conductive state; a detect circuit coupled in parallel electrical connection with the controllably conductive switching device, the detect circuit operable to provide a control signal representative of whether the controllably conductive switching device is conducting a load current to the lighting load; and a controller operatively coupled to the controllably conductive switching device and the detect circuit, the controller operable to render the controllably conductive switching device conductive at a predetermined time following a zero-crossing of the AC line voltage, and to subsequently determine in response to the control signal whether the controllably conductive switching device is conducting the load current to the lighting load; wherein the controller is operable to automatically adjust the dimmer switch to one of a first operating mode and a second operating mode in response to the control signal, the controller operable to adjust the low-end intensity setting to a first low-end intensity setting value in the first operating mode, and to adjust the low-end intensity setting to a second low-end intensity setting value in the second operating mode.