Abstract: An emergency lighting system provided with a U-shaped fluorescent tube having power supplied by a square wave oscillator connected to a relatively small sized battery. A battery charger is employed to charge the battery when the standard AC source is connected to the network. An electronic switching circuit is included which will switch the oscillator on when a network failure is sensed and will switch if off when the network appears to be operating properly. The switching circuit also ensure that the battery does not discharge below a particular voltage level.