Abstract: A two-wire dimmer for control of a lighting load from an alternating-current (AC) power source includes a semiconductor switch, a power supply, and a control circuit. The power supply includes an energy storage input capacitor that is able to charge only when the semiconductor switch is non-conductive. The control circuit continuously monitors the voltage on the input capacitor and automatically decreases the maximum allowable conduction time of the semiconductor switch when the voltage falls to a level that will not guarantee proper operation of the power supply. The dimmer of the present invention is able to provide the maximum possible conduction time of the semiconductor switch at high end (i.e., maximum light intensity) while simultaneously ensuring sufficient charging time for proper operation of the power supply, and hence, the dimmer.

Abstract: A light dimmer capable of receiving a faceplate fastener while thermally insulating the fastener from a heat-generating device, such as a triac or a field-effect transistor, is presented. In a preferred embodiment, the dimmer includes a thermally insulating boss integrally formed with the body of the dimmer such that the boss includes a fastener-receiving aperture adapted to be axially aligned with the fastener-receiving openings of the faceplate. In addition, the dimmer includes a heat-dissipating aluminum yoke to which the heat-generating device is in thermal communication, thereby allowing the yoke to act as a heat sink. The yoke has a fastener-receiving aperture formed therein in axial alignment with the fastener-receiving aperture of the thermally insulating boss, with the yoke fastener-receiving aperture proportioned to receive the fastener therethrough in non-contacting relationship.

Abstract: A method and apparatus are provided for detecting a short circuited semiconductor switch. The apparatus comprises a semiconductor switching device and a short circuited switch detection device. The semiconductor switching device comprises an input, an output, and a control input for switching the semiconductor switching device. The short circuited switch detection device comprises an input and an output. The input of the short circuited switch detection device is coupled to the semiconductor switching device, wherein the short circuited switch detection device detects a short circuit in the semiconductor switch switching device.

Abstract: A motorized shade control system is described in which electrostatic charges, generated by a shade fabric being reeled on to and off of a roller are conducted to and grounded by the shaft of a remote drive motor. The drive motor is ultraquiet, and includes a worm gear drive and single-stage reduction gear assembly which delivers about 0.010 to 0.005 horsepower, with motor output shaft rotational velocity limited to no more than about 30RPM. The motor is mounted within a two-part housing and is clamped between elastomeric acoustic dampers connected between pedestals extending from opposite interior wall surfaces to opposite sides of the motor. An H-bridge drive circuit powers the motor under the control of a microprocessor which can be addressed by an infrared remote transmitter or by a wall mount control. Soft start and soft stop circuits are employed to further reduce noise.