Emergency supply for fluorescent lamp - continuously reverses polarity of emergency DC current from rectified output of inverter

摘要

The emergency power supply is designed for use with a fluorescent lamp. It consists of a charging circuit, a battery, a static inverter and an electronic mains/standby changeover switch that connects the lamp to the emergency supply when the mains fails. The lamp is supplied with DC from a rectifier (4) connected to the static inverter (6) output when the mains power fails. The DC supply current has its polarity reversed automatically at given intervals of time by a reversing switch (3) controlled by a timer.