Electronic ballast to drive at least one gas discharge lamp, and methods to reduce total harmonic distortion of the ballast input current, and to reduce the current crest factor in an electronic ballast.

摘要

"ELECTRONIC LASTER TO DRIVE AT LEAST ONE GAS DISCHARGE LAMP, AND METHODS TO REDUCE THE TOTAL HARMONIC INPUT CURRENT DISTORTION, AND TO REDUCE THE CURRENT CREST FACTOR BY ONE." An electronic ballast for driving a gas discharge lamp includes a rectifier, a flattened circuit, an inverter having a first and second controllably conductive devices connected in series having complementary duty cycles, a control circuit for controlling the controllably conductive device, and a standalone "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 planed 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 flattened circuit is also one of the controllably conductive devices of the inverter.