| 摘要 |
PROBLEM TO BE SOLVED: To detect abnormality by using a single integrating means. SOLUTION: A comparator 131 detects the opening of a power discharge light 3, and a comparator 132 detects the short-circuit of the power discharge light 3. A capacitor 121 starts charging when a power source 1 is turned ON, and a comparator 129 suspends the output of a failure judgment signal while a charge voltage Vc reaches at least a forth reference voltage Vs4 (a first specified value). The capacitor 121 is charged toward a third reference voltage Vs3 (a second specified value) when the comparator 131 or the comparator 132 detects the opening or short-circuit ofthe power discharge light 3, and the comparator 129 outputs a failure judgment signal to a PWN 10 when the charge voltage Vc of the capacitor 121 raises the third reference voltage Vs3 . |
