Abstract: An electronic dimming ballast comprises a filament turn-off circuit for controlling the magnitudes of filament voltages supplied to the filaments of a gas discharge lamp. Each of a plurality of filament windings is directly coupled to one of the filaments and is operable to supply a small AC filament voltage to the filaments. The plurality of filament windings and a control winding are loosely magnetically coupled to a resonant inductor of an output circuit of the ballast. A controllably conductive device is coupled across the control winding. When the controllably conductive device is conductive, the voltage across the control winding and the filament windings falls to zero volts. The controllably conductive device is driven with a pulse-width modulated (PWM) signal so as to control the magnitudes of the filament voltages. The filament voltages are provided to the filaments before striking the lamp, and when dimming the lamp near low end.

Abstract: A wall-mountable electrical timer for controlling the delivery of power from an AC power source to an electrical load, such as a lamp or a fan motor, includes: a timer adjustment actuator for selecting a predetermined time period of operation for the load; a toggle actuator for starting the timer, turning off the timer, and placing the timer in a bypass mode of operation; a vertical linear array of light-emitting diode visual indicators for indicating the length of a predetermined time period, the time remaining, and whether the timer is in the bypass mode; a controllably conductive device for regulating the delivery of power from the AC source to the load; and a controller for receiving inputs from the timer adjustment actuator and the toggle actuator, and for transmitting outputs to the visual indicators and the controllably conductive device.

Abstract: The present invention provides a method of programming a preset intensity of a dimmer switch from a radio-frequency (RF) remote control. A user is able to adjust the intensity of the lighting load to a new intensity and subsequently press and hold a preset button on the remote control to program the new intensity as the preset intensity. The remote control transmits a wireless transmission to the dimmer switch, which immediately responds to the actuation of the preset button by controlling the intensity of the lighting load to an old preset intensity. The dimmer switch then blinks a light-emitting diode representative of the new intensity to provide feedback that the dimmer switch is in the process of programming the preset intensity to the new intensity. Eventually, the dimmer switch stores the new intensity as the preset intensity and stops blinking the light-emitting diode.

Abstract: A two-wire load control device, such as a dimmer, is operable to control the amount of power delivered to an electrical load, such as a magnetic low-voltage (MLV) load, and comprises a bidirectional semiconductor switch, a timing circuit, a trigger circuit having a variable voltage threshold, and a clamp circuit. When a timing voltage signal of the timing circuit exceeds an initial magnitude of the variable voltage threshold, the trigger circuit is operable to render the semiconductor switch conductive, reduce the timing voltage signal to a predetermined magnitude less than the initial magnitude, and to increase the variable voltage threshold to a second magnitude greater than the first magnitude. The clamp circuit limits the magnitude of the timing voltage signal to a clamp magnitude between the initial magnitude and the second magnitude, thereby preventing the timing voltage signal from exceeding the second magnitude.