Abstract: Various methods and systems are provided for controlling and shaping the current waveform for a solenoid in a fuel injector that has variable impedance.

Abstract: A power converter circuit regulates an output voltage of a power train circuit and controls the current in the power train circuit. A current sensor circuit measures a current in the power train circuit. A hysteretic comparison circuit compares the current in the power train circuit to positive and negative current limits. The hysteretic comparison circuit causes a positive current in the power train circuit to decrease in a positive current limit mode in response to the positive current in the power train circuit reaching the positive current limit. The hysteretic comparison circuit causes a negative current in the power train circuit to decrease in a negative current limit mode in response to the negative current in the power train circuit reaching the negative current limit. The hysteretic comparison circuit prevents a pulse width modulation controller from controlling the power train circuit during the positive and negative current limit modes.

Abstract: Various methods and systems are provided for controlling and shaping the current waveform for a solenoid in a fuel injector that has variable impedance.

Abstract: An electronic ballast for driving at least one lamp comprising a rectifying circuit operatively connectable to an AC line; a current drawing circuit connected across said rectifying circuit; and an inverter circuit connected to said rectifying circuit that supplies a lamp current to said at least one lamp; wherein said current drawing circuit draws current from said AC line when the instantaneous voltage of said AC line nears zero to reduce the total harmonic distortion of the input current drawn by said ballast.

Abstract: An electronic ballast for driving a gas discharge lamp includes a rectifier, a valley-fill circuit, an inverter having first and second series-connected controllably conductive switches having complementary duty cycles, a control circuit for controlling the controllably conductive switches, and an independent cat ear power supply to provide power to the ballast control circuits. The result is a ballast having substantially improved power factor, THD, and current crest factor. In a preferred embodiment, the valley-fill circuit includes an energy storage device that stores energy in response to a controllably conductive switch. In an especially preferred embodiment, the controllably conductive switch of the valley-fill circuit is also one of the switches of the inverter.

Abstract: An electronic ballast for driving at least one lamp comprising a rectifying circuit operatively connectable to an AC line; a current drawing circuit connected across said rectifying circuit; and an inverter circuit connected to said rectifying circuit that supplies a lamp current to said at least one lamp; wherein said current drawing circuit draws current from said AC line when the instantaneous voltage of said AC line nears zero to reduce the total harmonic distortion of the input current drawn by said ballast.

Abstract: An electronic ballast for driving a gas discharge lamp includes a rectifier, a valley-fill circuit, an inverter having first and second series-connected controllably conductive switches having complementary duty cycles, a control circuit for controlling the controllably conductive switches, and an independent cat ear power supply to provide power to the ballast control circuits. The result is a ballast having substantially improved power factor, THD, and current crest factor. In a preferred embodiment, the valley-fill circuit includes an energy storage device that stores energy in response to a controllably conductive switch. In an especially preferred embodiment, the controllably conductive switch of the valley-fill circuit is also one of the switches of the inverter.

Abstract: An electronic ballast for driving a gas discharge lamp includes a rectifier, a valley-fill circuit, an inverter having first and second series-connected controllably conductive switches having complementary duty cycles, a control circuit for controlling the controllably conductive switches, and an independent cat ear power supply to provide power to the ballast control circuits. The result is a ballast having substantially improved power factor, THD, and current crest factor. In a preferred embodiment, the valley-fill circuit includes an energy storage device that stores energy in response to a controllably conductive switch. In an especially preferred embodiment, the controllably conductive switch of the valley-fill circuit is also one of the switches of the inverter.

Abstract: An electronic ballast for driving a gas discharge lamp includes a rectifier, a valley-fill circuit, an inverter having first and second series-connected controllably conductive device having complementary duty cycles, a control circuit for controlling the controllably conductive device, and an independent cat ear power supply to provide power to the ballast control circuits. The result is a ballast having substantially improved THD, and current crest factor. In a preferred embodiment, the valley-fill circuit includes an energy storage device that stores energy in response to a controllably conductive device. In an especially preferred embodiment, the controllably conductive device of the valley-fill circuit is also one of the controllably conductive devices of the inverter.

Abstract: An electronic ballast for driving a gas discharge lamp includes a rectifier, a valley-fill circuit, an inverter having first and second series-connected controllably conductive device having complementary duty cycles, a control circuit for controlling the controllably conductive device, and an independent cat ear power supply to provide power to the ballast control circuits. The result is a ballast having substantially improved THD, and current crest factor. In a preferred embodiment, the valley-fill circuit includes an energy storage device that stores energy in response to a controllably conductive device. In an especially preferred embodiment, the controllably conductive device of the valley-fill circuit is also one of the controllably conductive devices of the inverter.

Abstract: An electronic ballast for driving a gas discharge lamp includes a rectifier, a valley-fill circuit, an inverter having first and second series-connected controllably conductive switches having complementary duty cycles, a control circuit for controlling the controllably conductive switches, and an independent cat ear power supply to provide power to the ballast control circuits. The result is a ballast having substantially improved power factor, THD, and current crest factor. In a preferred embodiment, the valley-fill circuit includes an energy storage device that stores energy in response to a controllably conductive switch. In an especially preferred embodiment, the controllably conductive switch of the valley-fill circuit is also one of the switches of the inverter.