| 摘要 |
PURPOSE:To provide a checker which enables effective detection and indication of the capacity of the battery and others by drawing a voltage of a checker coil wound around an output transformer of a high frequency inverter through a band- pass filter. CONSTITUTION:When the commercial power supply is artificially suspended, connected to a battery 9 through a contact 12, a transistor inverter 10 is actuated to feed a loop current of high frequency to a fluorescent lamp 1 via an output transformer 16. In this manner, the fluorescent lamp comes on in the emergency mode. A voltage is produced in a checker coil 25 in proportion to the output voltage, so that a given voltage develops in a band-pass filter 28. If the voltage should decrease before the end of the checking due to a reduction in the capacity of the battery 9 of the like, a transistor 23 fails to conduct while a transistor 20 conducts to allow a light emitting diode 21 to illuminate. This indicates that the fluorescent lamp 1 is unable to perform any imergency lighting as expected. At the same time, the checker V can detect and indicate not only the capacity shortage of the battery 9 but also trouble of the inverter 10 and the expiration of the fluorescent lamp 1. |
