Patent ID: 8198820
Filing Date: 2012-06-12
Classification: H05B,Y02B,Y10S

Abstract:
1. A dimmer switch adapted to be coupled between an AC power source and a lighting load for controlling the intensity of the lighting load between a high-end intensity setting and a low-end intensity setting, the dimmer switch comprising: a user-accessible adjustment actuator for changing the dimmer switch between first and second operating modes, wherein the first operating mode is provided to operate a first type of lighting load and the second operating mode is provided to operate a second type of lighting load including a ballast having a full-wave rectifier bridge having AC input terminals and DC terminals coupled to a bus capacitor, such that the low-end intensity setting is adjusted to a first low-end intensity setting value in the first operating mode, and the low-end intensity setting is adjusted to a second low-end intensity setting value greater than the first low-end intensity setting value in the second operating mode; wherein the dimmer switch is disposed in a housing that is adapted to be mounted by a mounting yoke in an electrical wallbox behind a faceplate, and wherein the user-accessible adjustment actuator is accessible when the dimmer switch is at least partially mounted in the electrical wallbox; the dimmer switch further 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 having a control input for controlling the controllably conductive switching device between an off-state and an on-state; a trigger circuit coupled to the control input of the controllably conductive switching device for rendering the controllably conductive switching device conductive each half-cycle of the AC power source; and a timing circuit operatively coupled in parallel electrical connection with the controllably conductive switching device for generating a timing voltage, the trigger circuit operable to control the controllably conductive switching device in response to the timing voltage to generate a dimmed hot voltage, the timing circuit comprising: a potentiometer for providing a variable resistance to thereby control the duration of the on-state of the controllably conductive switching device and thus the dimmed hot voltage; and a firing capacitor coupled to the output of the timing circuit for generating the timing voltage, the firing capacitor adapted to charge through the potentiometer; the trigger circuit triggering at a predefined timing voltage to render the controllably conductive switching device conductive; wherein in the first operating mode, a first impedance is coupled in parallel with the potentiometer, and in the second operating mode, a second impedance less than the first impedance is coupled in parallel with the potentiometer thereby to allow said firing capacitor to charge to the predefined timing voltage more rapidly in the second operating mode than in the first operating mode; wherein actuation of the user-accessible adjustment actuator controls whether the first impedance or the second impedance is coupled in parallel with the potentiometer; and wherein, when the low-end intensity setting is adjusted to the second low-end intensity setting value in the second operating mode, the dimmer switch is adapted to control the lighting intensity of the second type of lighting load comprising a full-wave rectifier bridge having AC input terminals for receiving the dimmed hot voltage and DC terminals coupled to a bus capacitor.