DIGITAL CONTROL ELECTRONIC BALLAST USING PIEZOELECTRIC TRANSFORMER

摘要

PURPOSE: A digital control electronic ballast is provided to reduce parts count and costs by eliminating the need of a lamp condenser, while achieving improved lamp turn-on characteristics and stability. CONSTITUTION: A digital control electronic ballast comprises a rectifier unit(41) for rectifying low frequency AC power and outputting DC power; a power factor compensator unit(42) for maintaining level of DC power output from the rectifier unit constant, by compensating power factor in accordance with the change of low frequency AC power; an inverter unit(43) for switching the DC power output from the power factor compensator unit and converting the DC power into a high frequency power signal; a resonator unit(44) connected to the output of the inverter unit, and which is constituted by a coil and a high output piezoelectric transformer, and transmits the high frequency power output from the inverter unit to a lamp; and a digital control unit(48) for controlling illuminance of the lamp by modulating the frequency for controlling switching cycle of the inverter unit during lamp turn-on/off operation.