Abstract: An electronic dimming ballast has a parallel loaded resonant output circuit plus a combination of pulse width modulation and frequency variation to accomplish the dimming of compact fluorescent lamps. The ballast operates at a fixed frequency throughout a selected range of light levels, with dimming control being done completely by duty cycle variation over this range of operation, and then smoothly moves to a variable frequency as the light output moves outside the selected range, with both duty cycle and frequency variation being the means of lamp light output control outside the selected range.

Abstract: A ballast adapted to power a fluorescent lamp as a function of a variable input signal, includes a power stage for providing power to a fluorescent lamp; a control circuit for controlling the power stage as a function of the variable input signal; a control circuit power supply for supplying control power to the control circuit; and a monitor and enabling circuit which permits the ballast to provide power to the lamp only when characteristics of the variable input signal meet predetermined criteria.

Abstract: Apparatus for controlling an electrical device by remote control including a control device coupled to the electrical device by a wire connection for providing power to the electrical device, the control device having an actuator for adjusting the status of the electrical device and a radio frequency transmitter/receiver and antenna for adjusting the status of the electrical device in response to control information in a radio frequency signal. The transmitter/receiver receives the radio frequency signal via the antenna and transmits a status radio frequency signal with information regarding the status of the electrical device. A master control unit has at least one actuator and status indicator and a transmitter/receiver for transmitting a radio frequency signal having the control information therein to control the status of the electrical device and for receiving the status information from the control device.

Abstract: A dimming control circuit provides power from an ac source to a compact fluorescent lamp. The circuit generally includes a resonant half-bridge inverter driven by a pulse-duration-modulated voltage, for providing a high-frequency ac voltage between the lamp electrodes. A combination inductive and capacitive snubber circuit reduces switching losses in the inverter and increases the efficiency of the dimming circuit. A low-voltage transformer connected across the resonant portion of the inverter provides voltage to heat the lamp filaments. The filament voltage is substantially constant over a range of pulse-durations providing a dimming range from about 100% to 1% of full light output. A power supply circuit having a power factor of about 0.95 provides both high-voltage and low-voltage dc power to the dimming circuit with minimal losses. A shutdown circuit is provided to shut off power to the lamp if the dimming circuit is miswired or a ground fault occurs.

Abstract: An energy-saving lighting control system is selectively operable in either a normal mode, in which certain lighting parameters (e.g., maximum and minimum light levels, fade rates, etc.) are preset and lighting level is determined by which of a plurality of inputs requires the least electrical power, or in an off-normal mode (e.g., a calibration or light-adjustment mode) in which certain parameters are adjustable by manually adjusting the position of a movable member, such as a wiper blade in a potentiometer. A microprocessor-based logic and control unit is adapted to automatically switch from the normal operating mode to the off-normal mode in response to movement of the movable member. After a predetermined time period following the most recent movement of the movable member, the logic and control unit stores the new level of the adjusted parameter, and returns to the normal operating mode. Preferably, the system has multiple outputs by which different types of fluorescent lamp ballasts can be controlled.

Abstract: In a fluorescent lighting controller, a switching circuit operates to selectively couple a bank of electronic ballasts to an AC power source (100-277 Volts, 50-60 Hertz). The switching circuit comprises a pair of relays, preferably connected in parallel, with one of such relays having a controllably conductive device, such as an electronic switch, and preferably a triac, connected in series therewith. With the relays open, an air gap isolates the power source and ballasts. In closing the relays in sequence, one relay provides a conductive path from the power source to the triac. After a suitable delay to allow the relay contacts to stabilize in the closed position, the triac is triggered to provide a conductive path from the power source to the ballasts, and a large current surge (as much as 300 amps) flow to the ballasts. After the current surge has subsided, the other relay is closed to provide a direct conductive path between the power source and ballasts.

Abstract: A hand-held programmer is provided for adjusting various functions of a multi-scene, multi-zone programmable lighting control. The programmer generally includes push-buttons for selecting particular scenes and zones to be programmed and for activating any one of the functions to be adjusted; namely, intensity, fade time, and fade delay. An alphanumeric LCD display includes a number of controllable display areas, adjacent to and aligned with the push-buttons, for identifying the names of the selected scene and zone and the function settings associated with them. A cylindrically elongated rotary encoder, having a knurled, rubbery surface, is easily manipulated to adjust the setting of the activated function and provides kinesthetic feedback, so that its adjustment can be coordinated with a visual perception of the lighting scene.

Abstract: A dimming control circuit provides power from an ac source to a compact fluorescent lamp. The circuit generally includes a resonant half-bridge inverter driven by a pulse-duration-modulated voltage, for providing a high-frequency ac voltage between the lamp electrodes. A combination inductive and capacitive snubber circuit reduces switching losses in the inverter and increases the efficiency of the dimming circuit. A low-voltage transformer connected across the resonant portion of the inverter provides voltage to heat the lamp filaments. The filament voltage is substantially constant over a range of pulse-durations providing a dimming range from about 100% to 1% of full light output. A power supply circuit having a power factor of about 0.95 provides both high-voltage and low-voltage dc power to the dimming circuit with minimal losses. A shutdown circuit is provided to shut off power to the lamp if the dimming circuit is miswired or a ground fault occurs.

Abstract: A remote wireless load control system wherein the power supplied to a load can be varied from a remote location using a remote control device not electrically wired to the load. The load control system includes a transmitter and a receiver, each having a control actuator for adjusting the power supplied to the load. Control can be conferred upon either the transmitter or the receiver immediately upon manipulation of the control switch, with the adjustment in power level occurring substantially instantaneously upon manipulation of the control actuator. Transmission of load level information between transmitter and receiver is by digitally pulse-coded infrared signal.

Abstract: A dimming system, which provides a time-varying current from a power source between the electrodes of a gas discharge lamp, simultaneously provides high-frequency, low-level current between the electrodes to sustain an electric discharge in the lamp when the time varying current alone is insufficient. The system provides reduced starting stress in the lamp and, therefore, longer lamp life by delaying the formation of an arc discharge, during start-up, until the electrodes have been heated. The system can be used with standard magnetic ballasts to provide full-range dimming of gas discharge lamps from 3 to 100 percent light output with minimal striations, lamp drop out, and flicker.

Abstract: A dimming circuit provides power from an ac source to a compact fluorescent lamp. The circuit generally includes a resonant circuit driven by a high-frequency switching inverter and a current feedback control system. The circuit is essentially an ac current source of unusually high impedance and provides substantially symmetrical high-frequency current to the lamp. This allows flicker-free dimming of compact fluorescent lamps over a wide range with good light output stability. A small amount of dc or low-frequency ac current may be simultaneously provided to the lamp. The resulting composite current waveform flowing through the lamp substantially eliminates visible striations over a dimming range from about 100% to 1% of full light output.

Abstract: An indicator lamp indicates the status of an electrically-powered load control system by providing dim light when the load power is off and a brighter light when the load power is on. In another embodiment, the lamp not only provides two levels of light to indicate whether or not power is on, but also provides a repetitive flash when power to the system is being controlled by remote control. The indicator lamp can also indicate a break in the load circuit. Depending on the embodiment, the break can cause the lamp to be either off or flashing, regardless of the position of the load power switch. Alternatively, a break in the load circuit can cause the lamp to provide substantially no light if the load power switch is in the "off" position, with full light in the "on" position.

Abstract: A dimming circuit provides power from an ac source to a compact fluorescent lamp. The circuit generally includes a resonant circuit driven by a high-frequency switching inverter. The resonant circuit is essentially an ac current source and provides sinusoidal current to the lamp, which loads the resonant circuit in parallel. A small amount of dc current is simutaneously provided to the lamp. The resultant asymmetric current waveform flowing through the lamp substantially eliminates striation over a dimming range from about 100% to 1% of full light output.

Abstract: A low voltage two wire dimming circuit comprises a voltage compensating circuit for regulating the RMS value of an AC voltage applied to a load and a correcting circuit for eliminating damaging DC current that may flow through the load. The voltage compensating circuit adjusts the firing angle of an electronic switch disposed in the dimming circuit to compensate for fluctuations in the AC supply voltage. The correcting circuit advances or retards the firing angle during selected half cycles to correct for asymmetries in the AC load voltage waveform caused by excessive DC current. According to the invention, there is also provided a two wire low voltage dimming circuit without voltage compensation but having improved dimming ability at low load currents and improved resistance to the flow of damaging DC currents.

Abstract: A high frequency dimming ballast dims to about 1 percent of rated output in a repeatable way so that parallel connected dimming ballasts will all produce the same light illumination when dimmed to a very low percentage of their rated light output. A first current sensor is connected in series with a semiconductor power switching device which is coupled to and controls power to the ballast. A second current sensor is connected directly to the lamp circuit to detect actual lamp current, particularly at low illumination conditions, for example at less than 10 percent of the rated light output. Lamp control under low illumination conditions is derived from the lamp current sensor and overrides control by the sensor in series with the transistor switch means.

Abstract: A low voltage two wire dimming circuit comprises voltage compensating means for regulating the RMS value of an AC voltage applied to a load and correcting means for eliminating damaging DC current that may flow through the load. The voltage compensating means adjusts the firing angle of electronic switch means disposed in the dimming circuit to compensate for fluctuations in the AC supply voltage. The correcting means advances or retards the firing angle during selected half cycles to correct for asymmetries in the AC load voltage waveform caused by excessive DC current. According to the invention, there is also provided a two wire low voltage dimming circuit without voltage compensating means but having improved dimming ability at low load currents and improved resistance to the flow of damaging DC currents.

Abstract: A load control switching system includes a switching element adapted to be coupled between a power source and a load. The switch element is operable in an ON state wherein it supplies power from the source to the load and an OFF state wherein it cuts off power from the source to the load. A control circuit controls operation of the switching element in response to the actuation of one or more short-throw, light-force switches which are each movable between a normally open and a momentarily closed position. The control circuit alternates the state of the switching element each time the short-throw, light-force switch is momentarily closed.

Abstract: A cover and support plate arrangement for a wall mounted device, such as a wall switch, display, dimmer, etc., for mounting to a wall box embedded in the wall and having overall surface dimensions greater than that of the wall box. The cover plate is juxtaposed over the front surface of the support plate and is spaced therefrom to provide an air gap between the cover plate and the support plate creating a chimney through which air currents may flow. The device includes an electric circuit having a heat generating device, such as a triac, which is thermally connected to the support plate and in series electrically with a controlled load. The cover plate casts a shadow along vertical sides of the support plate such that the vertical sides of the support plate are visible only when viewed at extreme angles with respect to an imaginary line perpendicular to the plane of the support plate or the wall in which the device is mounted.

Abstract: An improved push button switch has a highly desirable tactile feel. The switch includes a face plate having a front surface, a rear surface and an opening extending from the front to the rear surface, the opening having a geometric center as viewed from a position in front of the face plate. A push button is located in the opening. A pair of leaf springs are provided for coupling the push button to the face plate with at least a portion of the push button being biased against the rear surface of the face plate. A normally open electro-mechanical switch having a stationary contact and a movable contact is provided. The movable contact is biased against a portion of the rear surface of the push button at a location corresponding to the geometric center of the opening in the face plate.

Abstract: A dimmer switch and dimmer system is described in which dimming for the entire system is controlled from a single device while on/off switching is controlled by individual devices at multiple locations. The main dimming device contains an alternate action switching circuit for opening and closing the gate circuit of a controllably conductive device. Each of the remote location switching devices consists of respective low voltage switches, each operable to operate the alternate action switching circuit in the main dimmer device and are connected thereto by wiring which carries only signal level voltages and currents. Each remote switch may be a wall-mounted switch containing a single, relatively large area push button which momentarily closes a short movement, low activation force pair of contacts when the large area push button is depressed by pressure applied to any portion over its surface.