Patent ID: 7049764

Claim:
An electrodeless lighting apparatus using microwave comprising: a power controlling unit for detecting a rate of variability of voltage of inputted AC power, and generating fixed AC voltage and fixed oscillation current by compensating the rate of variability of the voltage; a high voltage transformer for converting the fixed AC voltage into high DC voltage, and outputting the converted high DC voltage; and a magnetron for generating microwave based on the fixed oscillation current and the high DC voltage, wherein the power controlling unit comprises: a rectification/smoothing unit for converting commercial AC power into DC power; a control unit for detecting a rate of variability of voltage of the commercial AC power, and generating a voltage compensating signal for compensating the rate of variability of the voltage; an inverting unit for converting voltage of the converted DC power into fixed AC voltage by varying a frequency of the DC power converted by the rectification/smoothing unit based on the voltage compensating signal of the control unit, a first transformer for converting the fixed AC power outputted from the inverting unit into predetermined fixed voltage and current, and applying the predetermined fixed voltage and current to a filament of the magnetron; and a second transformer for converting the fixed AC voltage outputted from the inverting unit into predetermined fixed voltage, wherein, the high voltage transformer converts predetermined fixed voltage outputted from the second transformer into high DC voltage, and outputting the converted high DC voltage to the magnetron.