Osram Sylvania Inc.

Osram Syvlania Inc.

Shashank Bakre

Nitin Kumar

Markus Ziegler

Thomas Schalton

Ayan Choudhury

John G Konopka

Arindam Chakraborty

Himamshu V Prasad

Naveen Yadlapalli

Robert Martin

Driss Baba

Christian Breuer

A multi-strike ballast to ignite an electrodeless lamp is disclosed, and includes an inverter circuit, a protection circuit, and a controller. The inverter circuit, upon activation, sends an ignition pulse to the lamp. The inverter circuit shuts down upon receiving a deactivation signal, and activates upon receiving an activation signal, triggering another ignition pulse. The protection circuit senses a change in a voltage associated with the lamp. The sensed changed may indicate that the lamp has not yet ignited or that the lamp is broken. The controller receives the sensed change in voltage and, in response, sends a deactivation signal to the inverter circuit. The controller waits a predetermined time and then sends an activation signal to the inverter circuit. The controller repeats until a change in voltage associated with the lamp is not sensed, or until a predefined number of repeats occur, providing multiple ignition pulses to the lamp.

Multiple strike ballast with lamp protection for electrodeless lamp

A ballast configured to connect to a set of lamps to energize the set of lamps is provided. The ballast comprises an inverter circuit for generating an oscillating power signal, wherein the oscillating power signal has a frequency, and a resonant tank circuit electrically connected to the inverter circuit for receiving the oscillating power signal and therefrom providing a lamp current to the set of lamps. A resistance circuit is connected to the inverter circuit. The resistance circuit has a resistance that defines the frequency of the oscillating power signal generated by the inverter circuit. A current control circuit is connected to the resistance circuit for adjusting the resistance of the resistance circuit as a function of a number of lamps that are connected to the ballast.

Ballast with current control circuit

A ballast comprises an inverter circuit for providing an oscillating current signal for energizing the at least one lamp. The inverter circuit comprises a first switching component and a second switching component each having a collector terminal, a base terminal, and an emitter terminal. And, each switching component is configured for alternately operating between a conductive state and a non-conductive state. A first collector-emitter circuit is connected between the collector terminal and the emitter terminal of the first switching component, wherein the first collector-emitter circuit has a first resistance of zero or more Ohms. A second collector-emitter circuit is connected between the collector terminal and the emitter terminal of the second switching component, wherein the second collector-emitter circuit has a second resistance of zero or more Ohms and the first resistance and the second resistance are unequal.

Ballast with anti-striation circuit

A ballast comprises an inverter circuit for connecting to a lamp and providing power thereto. The ballast includes a current feedback circuit connected to the inverter circuit and the lamp for controlling the frequency of the inverter circuit based on current feedback from the lamp. The ballast includes a switch circuit connected to the current feedback circuit and the lamp for enabling the current feedback circuit when the lamp is in a normal operating state and disabling the current feedback circuit when the lamp is in a low current operating state.

Switch circuit for a ballast

A ballast for energizing a lamp at a lighting level selected from a plurality of lamp lighting levels. The ballast includes a buck converter circuit configured to receive a DC voltage signal having a substantially constant magnitude. The buck converter circuit has a duty cycle for generating a lamp voltage output signal from the DC voltage signal. The lamp voltage output signal has a magnitude that is varied by the duty cycle to energize the lamp at the plurality of lamp lighting levels. A controller is configured to receive a dim input signal indicative of the selected lamp lighting level and to provide a control signal to the buck converter circuit as a function of the dim input signal. The control signal indicates a particular duty cycle corresponding to a lamp voltage output signal having a magnitude for energizing the lamp at the selected lamp lighting level.

Dim mode start for electrodeless lamp ballast

A two level lighting ballast is provided, which includes a self-oscillating inverter circuit and a control circuit. The inverter includes an input; an output to selectively provide current to energize a lamp; a switching circuit operating at a switching frequency; a feedback transformer; and an impedance component. The feedback transformer is connected to the output, and drives the switching circuit based on the lamp current. The impedance component is connected in parallel with the feedback transformer, and is operated by the control circuit. When the control circuit enables the impedance component, the switching circuit operates in a first frequency range, and a first lamp current is provided. When the control circuit disables the impedance component, the switching circuit operates in a second frequency range, and a second lamp current is provided. The first frequency range is lower than the second, and the first lamp current is greater than the second.

Two level lighting ballast

A three light level electronic ballast, and methods of operating lamps at three light levels, are provided. The ballast includes a rectifier, a power factor correction circuit, an inverter circuit, a first circuit, a second circuit, and a control circuit. The rectifier receives an AC voltage signal and produces a rectified voltage signal, which the power factor correction circuit receives and uses to provide a corrected voltage signal. The inverter circuit receives the corrected voltage signal and provides an energizing signal to power at least two lamps. The first circuit selectively reduces the current applied to the lamps by the energizing signal. The second circuit selectively prevents the second lamp from being energized by the energizing signal. The control circuit controls the first circuit and the second circuit.

Three light level electronic ballast

A ballast that selectively operates multiple lamps is provided. The ballast includes a switching network, capable of operating in a number of switching configurations. The ballast also includes a control circuit, and two lamp control switches. The control circuit is connected to the switching network, and provides respective control signals via respective output terminals as a function of the switching configuration of the switching network. Each lamp control switch is in parallel with its lamp and is connected to a respective output terminal. The first lamp control switch is connected to a ballast power supply, and either provides power to the first lamp or does not, depending on the first control signal. The second lamp control switch is connected to the first lamp control switch and to ground, and either provides power to the second lamp or does not, depending on the second control signal.

Multiple lamp lighting level ballast for series connected lamps

A lighting system converter circuit of a lamp power converter to selectively operate a plurality of lamps connected thereto is provided. The lighting system converter circuit includes a first impedance circuit and a second impedance circuit. Each impedance circuit includes an input terminal, an impedance component, and a switching network. The impedance components are each configured to connect in series with the lamps. Each input terminal is configured to receive a control signal that indicates a state of a switch. Each control signal has a first logic level, indicating the switch is non-conductive, and a second logic level, indicating the switch is conductive. Each switching network is connected to its respective input terminal and in parallel with its respective impedance component, and is configured to selectively operate between a conductive state and a non-conductive state, as a function of the logic level of its respective control signal.

Multiple light level electronic power converter

A electrodeless lamp including a fluorescent discharge vessel, a tip, an amalgam, a lamp core, and a heater. The vessel contains a gas having a partial vapor pressure and a fluorescent material. The tip has an inner end engaging the vessel, and an opening in communication with the gas. The amalgam is positioned within the opening, in heat transfer relation with the tip. When the temperature of the amalgam decreases, mercury vapor in the gas condensates onto the amalgam, causing a decrease in the partial vapor pressure of the gas. The opposite occurs when the amalgam temperature increases. The lamp core generates a magnetic flux, causing an electrical discharge in the gas. The heater includes a positive temperature coefficient connected to a winding of the lamp core. The heater is in heat transfer relation with the tip and heats the tip when the electrodeless lamp is in a dimming mode.

Amalgam tip temperature control for an electrodeless lamp

A multi-strike ballast to ignite an electrodless lamp is disclosed, and includes an inverter circuit, an output voltage detection circuit (OVDC), and an inverter shutdown circuit. The inverter circuit, upon activation, sends an ignition pulse to the electrodeless lamp. The inverter circuit shut downs upon receiving a deactivation signal, and activates upon receiving an activation signal, triggering another ignition pulse. The OVDC detects an output voltage across the lamp. The inverter shutdown circuit includes a multi-strike diac and receives the detected output voltage. The multi-strike diac breaks upon the output voltage reaching a predetermined level. In response, a deactivation signal is sent to the inverter circuit. The multi-strike diac turns off upon the output voltage falling below the predetermined level. In response, an activation signal is sent to the inverter circuit, triggering a further ignition pulse. The process repeats, providing multiple ignition pulses to the lamp.

Multiple strike ballast for electrodeless lamp

A ballast to energize a lamp is provided. The ballast comprises a buck converter connected to an inverter via a switching component. The buck converter includes a transistor, a capacitor, a diode, and an inductor. The switching component has a predetermined breakover voltage value and is configured to provide a start up signal to the inverter when voltage at the switching component increases to the predetermined breakover voltage value. A control circuit is configured to monitor the voltage at the switching component while the voltage at the switching component increases to the predetermined breakover voltage, and is configured to generate a gate drive pulse at a gate terminal of the transistor when the voltage at the switching component reaches a predetermined voltage that is less than the breakover voltage of the switching component.

Starting circuit for buck converter

A ballast for dimming a lamp is provided. The ballast includes an inverter circuit for providing a lamp current for energizing the lamp and a dim interface for receiving an input indicative of a selected lighting level. A control circuit is connected to the dim interface for generating a pulse-width-modulated signal having a duty cycle corresponding to the selected lighting level. A switching network is connected to the control circuit for receiving the pulse-width-modulated signal. The switching network operates between a conductive state and a non-conductive state as a function of the pulse-width-modulated signal. An impedance device is connected across the switching network and is configured for connecting in series with the lamp so that the impedance device receives the lamp current when the switching network is operating in the non-conductive state and the lamp current bypasses the capacitor when the switching network is operating in the conductive state.

Dimmable instant start ballast

A bi-level lamp ballast to selectively operate two lamps is provided. The ballast includes a control circuit having an input, connected to a switching network, and an output, which provides a particular control signal based on the state of the switching network. The ballast also includes respective lamp control switches, each having respective outputs. The first switch is connected to the output and a ballast power supply. In its first state, it connects the ballast power supply to its first output, and in its second state, it connects the ballast power supply to its second output. The second switch is connected to the output and a ground. In its first state, it connects the ground to its first output, and in its second state, it connects the ground to its second output. The state of each lamp control switch depends on the control signal generated by the control circuit.

Bi-level lamp ballast

A lamp driver circuit to selectively energize one or more lamps is provided. The inverter circuit has a transformer with primary and secondary windings to provide voltage to the lamps. A filter is connected to the primary winding to receive a primary winding signal representative of the voltage across the primary winding. The primary winding signal has a frequency spectrum and the filter detects a particular characteristic of the frequency spectrum that is indicative of an end of life (EOL) condition of the one or more lamps. A control circuit is connected to the inverter circuit and to the filter. The control circuit is configured to discontinue energizing of the one or more lamps by the inverter circuit when the particular characteristic of the frequency spectrum of the primary winding signal is detected by the filter.

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Woburn, MA, United States of America

Shashank Bakre