PROBLEM TO BE SOLVED: To improve reliability and safety in an emergency light block when an emergency light is formed from a normal electronic ballast having a plurality of rated input voltages serviceable over a wide range of supply voltage.;SOLUTION: A lighting system for emergency is equipped with a charging circuit 4 for a secondary battery B by lowering the voltage of the commercial power Vs, an inverter 5 for emergency to light a discharge lamp 2 using the secondary battery B as the power supply, a normal electronic ballast 1 to light the discharge lamp 2 using the commercial power Vs as the power supply, a power supply switch 30 to separate the electronic ballast 1 from the commercial power Vs when it is sensed that the voltage of the commercial power Vs has become in the extent 40-85% of the rated value thereof, and a change over circuit 6 to change over the discharge lamp 2 from the output side of the ballast 1 to the out put side of the inverter 5 and also start the operation of the inverter 5.;COPYRIGHT: (C)2006,JPO&NCIPI
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