| 摘要 |
PURPOSE: A high efficiency piezo-electric ballast is provided to allow piezo-electric ceramics to be applied to the ballast for fluorescent lamp and high voltage discharge lamp, while eliminating the necessity of a soft start circuit. CONSTITUTION: A high efficiency piezo-electric ballast comprises an over-current and over-voltage protection element; a power factor improvement circuit connected to an AC power source including an EMI prevention circuit; a rectifier connected to the power factor improvement circuit; a pulse generator for receiving signals from an input power and generating a frequency; a switching frequency setting circuit for setting the frequency; two field effect transistors for switching an AC voltage output from the rectifier in accordance with the pulse generated from the pulse generator; an inductor(1) connected between a discharge lamp and a common output of the two field effect transistors; and a piezo-electric coupler(5) connected in parallel to the discharge lamp.
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