| 摘要 |
PURPOSE:To detect a broken filament in one of arranged lamps and also which one of their lamp lighting circuits malfunctions by counting time from a point of time of the instantaneous stop of an a.c. power output to a point of time of detecting the instantaneous stop to be compared with each of judgment time so as to discriminate a lamp whereto the judgment time corresponding with the counted time is preset. CONSTITUTION:An output change detecting means 6 inputs an a.c. power output to detect a change in the a.c. power output caused by an opening phenomenon in the secondary winding side of each of transformers, CT1 to CTn. Furthermore, a lamp discriminating means 9 whereto judgment time different from one another for each of lamps is preset counts time from a point of time of the instantaneous stop of the a.c. power output by an a.c. power controlling means 8 to a point of time of detecting the instantaneous stop by the output change detecting means 6 to be compared with each of the judgment time so as to discriminate the lamp whereto the judgment time corresponding with the counted time is preset. This permits detecting the number of the lamps having their broken filaments, which one of all lamps has the broken filament and also the arranged position of the lamp having the broken filament. |
