| 摘要 |
PURPOSE:To enable the reduction of lamp flicker even in a low gradient by synchronizing the first high frequency output, second high frequency output and pulse width control output with one another. CONSTITUTION:The output of a main power supply is synchronized with a pulse cycle for dimmer control, and an auxiliary power supply as well. Namely, when an inverter 1 for main electric discharge, a dimmer control circuit 3 and an inverter 5 for auxiliary electric discharge are synchronized with one another, using a clock signal from in oscillation circuit 6, a relationship among phases of each voltage waveform including the dimmer control pulse signal is fixed (synchronized). Lamp discharge, therefore, always rises in the same condition and the size and form of the rising portion becomes fixed. According to the aforesaid construction, the lamp flicker can be prevented. |
