Abstract: A high frequency gas discharge lamp dimming ballast with good line power factor is disclosed. The unit is controlled by a current sensing loop which senses control switch current rather than lamp current and employs simple circuitry with sufficiently rapid control response necessary to maintain high line power factor and stable lamp operating characteristics over a very wide range of light output. An isolated output transformer provides protection against most common miswire conditions and accurately regulates lamp energy over a wide range of input and lamp arc voltage conditions. A pulse width modulated control input provides an isolated control input for easier wiring and reduces the susceptibility of the control to noise interference.

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.

Abstract: Individual banks of gas discharge lamps are provided with a common dimming control system. If a bank of lights is turned on while others are on and in a dimmed condition, the voltage applied to all lamps is increased over a relatively short period of time to full voltage to ensure the proper striking of the new bank of lamps but over a sufficiently long time period that users of the dimmed banks of lamps will not be noticeably affected by the change in lamp output. Full power is then maintained for a sufficiently long time to ensure proper lamp striking and stabilization and all banks are then very gradually returned to the original dimmed illumination condition which was set before the new lamp bank was energized. A long time delay and a short time delay are applied to respective inputs of a comparator to enable the initiation of the lamp striking sequence for the new lamp bank and prevents the initiation of the lamp striking sequence due to short time disturbances on the line.

Abstract: A pulse network is connected to the inductive ballast of a fluorescent lamp dimmer and includes a discharge resistor in parallel with the pulse network capacitor. The resistor size is such that it will completely discharge the capacitor prior to the initiation of any phase delayed half wave voltage which is applied to the ballast.

Abstract: A gas discharge lamp control circuit for an inductive ballast includes anti-parallel connected controlled rectifiers connected in series with the a.c. source and the ballast and anti-parallel connected controlled rectifiers which are connected in series with a current limiting and energy diversion capacitor and in shunt with the ballast. The controlled rectifiers of the series and shunt switching assemblies are controlled so that, in any given half wave, the related controlled rectifier of the shunt switching means turns on to discharge a capacitor into the normally conducting controlled rectifier of the series switching means to produce a notch in the voltage wave form applied to the inductive ballast. The capacitor acts as a current limiting impedance and acts to permit reversal of the voltage during the notch interval in the input voltage to the ballast, thereby to increase the RMS content of the voltage wave form.

Abstract: An illumination control device controls the level of artificial lighting depending upon the intensity of natural light in the area being controlled. A single adjustment is used to set the switching point at which the illumination control device becomes operative. An indicator is provided to indicate the adjustment status before a change in the artificial light condition occurs. A filter is employed to produce turn-on and turn-off time delays which differ from one another and are automatically changed in accordance with the instantaneous light level which exists prior to a necessary circuit switching operation.

Abstract: The input energy to a gas discharge lamp is controlled over a given range to obtain output light regulation in a controlled fashion for different kinds of gas discharge lamps, including fluorescent lamps, high intensity discharge lamps and others associated with any type ballast, including conventional non-dimming type ballasts. A suitable circuit switches each half wave of an input a-c wave form from some instantaneous value greater than zero to a substantially zero value and then back to a value greater than zero one or more times in each half cycle. The time duration of the substantially zero energy interval is varied to vary the total energy applied to the gas discharge lamps. In a preferred embodiment, a first high speed electronic switch is connected in series with the a-c source and lamp ballast and a high speed electronic shunt switch is connected across the a-c line and ballast input. The series switch is opened to produce the zero energy interval.

Abstract: In an area illuminated by both artificial and natural light sources, a control system is implemented to reduce the energy consumption by proportionately dimming the artificial sources to a level such that the sum of natural plus artificial light is held essentially constant. Use of an open loop sensing scheme allows the control system to operate over a wide range of conditions with no oscillations and good control of the total illumination level.

Abstract: An illumination control system for gas discharge lamps which can be dimmed is provided in which a central inverter produces a sinusoidal output voltage at about 23 kHz. The amplitude of the inverter output is adjustable to dim the lamps. A transmission line consisting of spaced wires having respective thick insulation sheaths distributes the high frequency power to remotely located assemblies of ballasts and lamps. The ballasts consist of passive linear components. A high power factor rectifier network is disclosed for providing a d-c input to the inverter from the 50/60 Hz mains. The inverter circuit is provided with novel controls for gradual start-up and turn-off and is protected against load fault currents and internal fault currents. Automatic and manual resets are provided for internal fault current and load fault current, respectively. The basic inverter circuit consists of two alternately conducting controllably conductive power switching devices.

Abstract: An illumination control system for gas discharge lamps which can be dimmed is provided in which a central inverter produces sinusoidal output voltage at about 23 kHz. The amplitude of the inverter output is adjustable to dim the lamps. A transmission line consisting of spaced wires having respective thick insulation sheaths distributes the high frequency power to remotely located assemblies of ballasts and lamps. A high power factor rectifier network is disclosed for providing a d-c input to the inverter from the 50/60 Hz mains. Several ballasts are disclosed, which consist principally of circuits using passive linear components. Some of the ballasts disclosed are conjugate ballasts which are those made of complex conjugate impedances which resonate with or near the input power frequency. Some ballasts disclosed are non-linear when the lamp is out in order to limit the open circuit voltage. The ballasts disclosed all have the following characteristics:(a) good power factor (above 0.

Abstract: An illumination control system for gas discharge lamps which can be dimmed is provided in which a central inverter produces an output voltage at a high frequency which can be about 23 kHz. The amplitude of the inverter output is adjustable to dim the lamps. A transmission line consisting of spaced wires having respective thick insulation sheaths distributes the high frequency power to remotely located assemblies of ballasts and lamps. The ballasts consist of passive linear components. A high power factor rectifier network is disclosed for providing a d-c input to the inverter from the 50/60 Hz mains.

Abstract: The invention is an electronic fuel control system for an internal combustion engine having a first capacitance which is charged to a value indicative of the engine's speed during a first rotational interval of the engine. At the end of the rotational interval the charge on the first capacitance is transferred to a second capacitance which is further charged at a predetermined rate during a second rotational interval. A comparator compares the value of the charge on the second capacitance with a signal indicative of the engine's load. The comparator generates a pulse width signal indicative of the engine's fuel requirements during the interval the charge on the second capacitance is less than the value of the load signal.

Abstract: An electrical fuel injection system incorporates electromagnetic injectors wired in two groups and which are operated on alternate cycles during low speed and normal operation. With increasing power demands, the fuel injection computer supplies pulses of increasing length to keep the injectors open longer and supply more fuel to the engine. Two trains of timing pulses are initiated by reed switches operated by the distributor, and each is connected to a pair of latch circuits operative to provide timing pulses on one channel through gate devices to one set of injectors and to block pulses on a second channel to the other set of injectors. The subsequent signal from the other reed switch results in a timing pulse in the second channel. These timing pulses are supplied to the fuel injection computer to initiate the injection pulses and to AND gates which also receive the timing pulses.

Abstract: An electronic fuel control system for an internal combustion engine is disclosed capable of providing an enriched fuel/air mixture to the engine as a function of the engine's temperature and the engine's load during the transient warm up period. The fuel control unit embodies a full load warm up enrichment circuit controlling, in response to engine temperatures below a predetermined temperature and engine loads as determined from the pressure in the engine's intake manifold, the quantity of fuel being delivered to the engine. In the preferred embodiment the full load warm up enrichment circuit is a current sink sinking a portion of the current charging the injection timing capacitor in the electronic control unit to increase the duration of the generated injection fuel delivery pulses.