| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device which prevents stress due to instant voltage of AC power supply or power failure, and has no error operation by noises generated by switching operation. SOLUTION: The discharge lighting device has a means of stopping switching by discriminating drop of power supply voltage. The device comprises a level discriminating part 45 for discriminating drop of a rectified current output level, a counter circuit which inputs an output signal and a clock signal of the level discriminating part 45 and is composed of at least one counter A, B for counting N times (N≥1) the input frequency of the clock signal, a delay circuit 48 which delays for a prescribed time the Nth counter signal outputted from the counter circuit, and a stop signal generation circuit (RS latch) which inputs the output signal from the delay circuit 48 and outputs a stop signal for stopping the drive signal. COPYRIGHT: (C)2007,JPO&INPIT |
