| 摘要 |
PURPOSE:To prevent deterioration of characteristics due to a transient phenemenon by a method wherein, when a fluorescent lamp or the like is lighted with an inverter, a voltage to be applied to the inverter is switched either to a complete oscillating condition or an incomplete oscillating condition according to a high or low battery voltage. CONSTITUTION:When a fluorescent lamp 28 of an emergency lighting system or the like is lighted with a battery 11 through an inverter circuit 12, the voltage of the battery 11 is detected by a detecting section 32 and in proportion to the above output, two signals are outputted from a control section 33 alternately with a variable time ratio. And by these two signals an ''on'' or ''off'' signal is given to a transistor 23, the voltage ''c'' to be applied to the inverter 12 becomes a half-operating voltage when the battery voltage is high and the voltage ''d'' becomes a complete operating voltage when the battery voltage is low. Therefore, a transient phenomenon at the switching time of the inverter 12 is suppressed, a light-off time of a fluorescent lamp is eliminated and an effective utilization of the battery 11 can be accomplished. |
