ELECTRONIC BALLAST FOR DISCHARGE LAMPS

摘要

Ballast and starting circuits for controlling current and voltage applied to an electrical discharge lamp (700). The ballast uses a dual polarity converter (610) to provide a continuous supply of positive and negative current at outputs (611 and 612) respectively. Modulators (620 and 630) are connected between positive and negative outputs (611 and 612), and positive and negative discharge switching means (Q103 and Q104) which controls the positive and negative current supplied to the discharge lamp (700). The negative and positive lamp discharge periods are controlled to operate asynchronously, and preferably in an alternating current mode of operation to the lamp. Positive and negative regulators (661 and 662) are also preferably included to regulate the modulated positive and negative currents from the positive and negative modulators and form secondary energy storage devices.