| 摘要 |
PURPOSE:To obtain a discharge lamp lighting device generating no ripple, without using a rectangular wave electrode. CONSTITUTION:When the output from a full wave rectification circuit 1 is low, the OFF period of a diode D1 is extended, the boosting amount by a resonance circuit is increased, and the voltage induced at an output winding Tr2 is raised. Even though the output voltage of an inverter circuit 2 is raised, the frequency of a switch Q1 for oscillation is increased by the frequency control from a control circuit 3, and the output voltage of the output winding Tr2 is made in the lowering direction. When the output from the full wave rectification circuit 1 is high, the ON period of the diode D1 is extended, the boosting amount by the resonance circuit is reduced, and the voltage induced at the output winding Tr2 is lowered. Even though the output voltage of the inverter circuit 2 is lowered, the frequency of the switch Q1 for oscillation is reduced by the frequency control from the control circuit 3, and the output voltage of the output winding Tr2 is made in the rising direction. Even though a false sine wave is made as the input voltage, the generation of a ripple current is prevented. |
