| 摘要 |
PURPOSE: To maintain the sinusoidal waveform of the current of an alternating current input power source, and to generate the stabilized luminance without generating the flicker in a discharge lamp. CONSTITUTION: An alternating current input power source is connected to input terminals U, V, and the current is converted to the pulsating current by a rectifying circuit 2 through a filter 1 for high frequency. This pulsating current is converted to the high frequency at about 100kHz by a step-up-and-down type converter circuit 3. Constant power direct current output is generated through a rectifying circuit of the secondary side of a transformer T. A switching element Q1 of the step-up-and-down type converter circuit 3 is controlled by a computing control circuit 6 so that the sinusoidal waveform of the input current is maintained and that the constant power output is obtained. This constant power direct current output is converted to the low frequency at about 100Hz-300Hz, and supplied to output terminals (u), (v). Stabilized luminance is obtained by connecting a discharge lamp 5 to the output terminals (u), (v). |
