Energy Savings, Inc.

Motorola Lighting, Inc.

Energy Savings, Inc., a Delaware Corporation

Peter W Shackle

Kent E Crouse

Ronald J Bezdon

Randy G Russell

Patrick J Keegan

John G Konopka

William Lawrence Keith

Donald G Huvaere

Michael W Bandel

Ming Liang Wu

Grigoriy Mirskiy

Gueorgui L Grouev

J Ray Wood

Boyko Boykov

Gas discharge lamps having filaments at each end thereof are operated in groups according to the power applied to separate line inputs to the ballast. The filaments of the lamps in a first group are powered by a first inverter that provides lamp current to a second group. The filaments of the lamps in the second group are powered by a second inverter that provides lamp current to the first group of lamps. Thus, even if an inverter is turned off, the lamps powered by that inverter are in a pre-heated state for instant starting. Power is coupled to the filaments by a network that is relatively insensitive to changes in frequency.

Electronic ballast with cross-coupled outputs

A microprocessor controlled ballast includes a single front end and a plurality of inverters separately controlled by a single microprocessor. Lamps are operated in groups according to separate line inputs to the ballast. Total power is reduced to fifty percent or less if a line input is off.

Electric Ballast with selective power dissipation

A microprocessor controlled ballast includes a single front end and a plurality of inverters separately controlled by a single microprocessor. Lamps are operated in groups according to separate line inputs to the ballast.

Electronic ballast with selective load control

An electronic ballast includes a zener diode in series with the bulk capacitor of the ballast to provide a charging voltage for a small capacitor that powers a power factor correction circuit within the ballast. A SCR in parallel with the zener diode shuts off the zener diode after the power factor correction circuit begins operation.

Fast starting, surge limited, electronic ballast

An ballast includes a variable frequency boost circuit and a driven half-bridge inverter having a series resonant, direct coupled, parallel output. A control circuit includes a variable frequency driver section, a multivibrator section, and a sensing section. The variable frequency driver changes frequency smoothly, i.e. without discontinuities. The multivibrator section acts as a switch that is enabled or disabled by the sensing section for controlling the frequency of the inverter. Lamp current is required for continued operation of the control circuit. The multivibrator section controls starting by causing the inverter to produce an output signal having a trapezoidal envelope. In the event of an arc, the control circuit quenches the arc and the multivibrator periodically pulses the lamp to attempt to re-start the lamp.

Electronic ballast deriving auxilliary power from lamp output

An instant start ballast includes a variable frequency boost circuit and a driven half-bridge inverter having a series resonant, direct coupled, parallel output. A control circuit includes a variable frequency driver section, a multivibrator section, and a sensing section. The variable frequency driver changes frequency smoothly, i.e. without discontinuities. The multivibrator section acts as a switch that is enabled or disabled by the sensing section for controlling the frequency of the inverter. Lamp current is required for continued operation of the control circuit. The multivibrator section controls starting by causing the inverter to produce an output signal having a trapezoidal envelope. In the event of an arc, the control circuit quenches the arc and the multivibrator periodically pulses the lamp to attempt to re-start the lamp.

Electronic ballast producing voltage having trapezoidal envelope for

An electronic ballast for a gas discharge lamp includes an AC to DC converter for changing alternating current at power line voltage to direct current and an inverter powered by the converter and having a series resonant, direct coupled output coupled to the lamp. The inverter includes an AC switch having a diode bridge defining an AC diagonal and a DC diagonal and a transistor connected across the DC diagonal. The primary winding of a filament transformer is connected across the AC diagonal of the bridge and the transistor is coupled to the microprocessor for controlling current through the primary winding. The microprocessor is programmed to close the AC switch while the lamp is starting and to open the switch after the lamp is started, thereby cutting off the filaments from a source of power and reducing the power consumed by the ballast during normal operation. A resistor in series with the transistor is used to detect filament resistance and provide an indication of lamp type.

Electronic ballast with filament cut-out

An electronic ballast includes an AC to DC converter for power factor correction, a bulk capacitor for storing energy from the converter, and a microprocessor controlled, half-bridge inverter including a series resonant, direct coupled output. Input ports of the microprocessor are coupled to several locations within the ballast to monitor the operation of the ballast or the operation of a gas discharge lamp coupled to the ballast. An analog voltage limiter overrides the microprocessor to limit output voltage under fault conditions. A storage capacitor, connected in series with the bulk capacitor, stores energy at low voltage for powering the microprocessor. The microprocessor is programmed to provide lamp protection features, lumen maintenance, and a warm-up period for a lamp. The microprocessor is also programmed to meet the operating requirements of world markets and of different lamp types.

Microprocessor controlled electronic ballast

An electronic ballast includes an inverter producing pulses having a DC component, an output circuit connecting the filaments of one or more lamps in series, and a control circuit for detecting direct current through the filaments. The control circuit includes a capacitor charged by the DC component. When the voltage on the capacitor reaches a predetermined value, the ballast applies a high voltage to the lamps. The predetermined value is not reached unless a direct current passes from the output of the inverter through all lamp filaments to the capacitor. If a lamp filament is not intact, the inverter will not apply high voltage to the lamp.

Electronic ballast that monitors direct current through lamp filaments

An electronic ballast includes a converter coupled to a variable frequency inverter and a series resonant, parallel loaded output coupled to the inverter. The frequency of the inverter increases when the supply voltage from the converter decreases. The converter includes a full wave rectifier producing a first voltage and an unregulated boost circuit producing a second voltage which is combined with the first voltage to produce the supply voltage. The amount of boost, and therefore the magnitude of the supply voltage, is varied to provide dimming. Dimming is controlled mechanically, via a potentiometer, or electrically, via a control input. Dimming also occurs in response to changes in the first voltage, i.e. from changes in the voltage on an AC power line or from changes in the voltage provided by a capacitive dimmer coupled between the ballast and an AC power line.

Externally dimmable electronic ballast

An electronic ballast has a high voltage portion and a low voltage portion. The high voltage portion includes a converter, having a variable frequency boost circuit, and a half-bridge, driven inverter having a series resonant, direct coupled output. The low voltage portion of the ballast includes a control circuit and fault detectors for shutting off the boost circuit and the inverter circuit. The fault detectors consume very little power when the ballast and lamp are functioning normally. Separate magnetics are used for boost, inverter, and output. Each magnetic is essentially cubic in shape and carries as little current as possible.

Low height ballast for fluorescent lamps

An electronic ballast includes a boost circuit, a low voltage control circuit, and a driven inverter in a half-bridge, push-pull, series resonant, parallel loaded configuration. The boost circuit includes a low voltage output for powering the control circuit. In the event of a fault, the control circuit shuts off the boost circuit and the inverter. A sense capacitor is in series with the lamps and the voltage across the capacitor prevents a timer in the control circuit from shutting off the ballast. The timer circuit waits a period longer than the time it takes for the lamps to start normally. The sense capacitor is either in series with the lamp across the resonant capacitor or is in series with the resonant capacitor.

Capacitive lamp out detector

A lamp protective, electronic ballast includes a lamp voltage detector having a capacitor and resistor series connected across a discharge lamp. The junction of the resistor and capacitor is coupled to a voltage sensitive switch for detecting DC offset on the lamp and excessive AC voltage on the lamp. The switch is more sensitive to DC offset than to excessive AC voltage and is disabled while the lamp is started.

Lamp protective, electronic ballast

An electronic ballast includes a triggered boost circuit, a driven inverter, and a low voltage signal generator in a a half-bridge, push-pull, series resonant, parallel loaded configuration. The boost circuit is triggered by a voltage from the inverter and the inverter is controlled by the low voltage signal generator. The boost circuit includes a low voltage output for powering the signal generator. In the event of a fault, the operation of the signal generator is interrupted, thereby shutting off the boost circuit and the inverter. A DC blocking capacitor is in series with the lamps and a resistor is connected in parallel with the DC blocking capacitor. The ballast is started by a pulse of displacement current through the lamp filaments to the boost circuit. Since the lamp filaments must be intact, the ballast does not begin a lamp starting sequence until lamps are connected to the ballast.

Booster driven inverter ballast employing the output from the inverter

A power factor corrected electronic ballast circuit uses two transformer components. An inductively coupled charge pump technique is used for power factor correction while the gates of the transistor switches are driven directly from a resonant inductor.

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Arlington Heights, IL, United States of America

Peter W Shackle