| 摘要 |
PROBLEM TO BE SOLVED: To achieve protection control against an abnormal operation caused by impedance defects of a power supply system connected with an input end of a discharge lamp lighting device. SOLUTION: The discharge lamp lighting device has an input voltage monitoring function (comparators CMP0-CMP2 and an RS flip-flop 83), and a power supply failure determining function (a counter 84) for counting the number of times switching from an operating state to a standstill state on the basis of reduction of input voltage and determining as power supply failure when the number of counting exceeds the designated number. Designated response time is required for determination of reduction of input voltage, and a response time Td0 during no-load control is set up to be smaller than a response time Td1 during lighting control. COPYRIGHT: (C)2011,JPO&INPIT |
