| 摘要 |
A lamp failure detection system for detecting lamp failure in a lighting circuit having a plurality of lamps connected with the secondary side circuits of each of a plurality of current transformers, the current transformers having their primary side circuits connected in series to an alternating current power supply. The detection system includes a plurality of lamplight failure detectors (42 or 21) fitted one to each of the lamps for detecting a lamp failure, a power control unit (18) for performing repeatedly the momentary interruption of the output of the alternating power supply, a plurality of lamplight circuit control units (27) fitted one to each of the lamplight failure detectors for electrically closing the secondary side circuit of the current transformer when a lamp failure is detected by the lamplight failure detector and for opening the secondary circuit for a fixed time when the number of momentary interruptions of the alternating current power supply which occur after the lamp failure is detected reaches a predetermined number of momentary interruptions set for each lamp, a lamplight failure judgement unit (16) for detecting lamp failure based on variations in the outputs of alternating current power supply, and a lamplight failure locator unit (19) for deciding which of the lamps has failed based on the comparison between the number of momentary interruptions from the time when a first lamp failure is detected with the predetermined number of momentary interruptions set for each lamp. <IMAGE> |
