E3 What is a circle?

E stands for emergency storage battery, and the sign with "E" is emergency lighting.

The emergency lighting lamp consists of light source, light source driver, rectifier, inverter, battery pack, sign lamp shell, etc.

At ordinary times, 36V drives the light source normal lighting through the light source driver and supplements the battery pack through the rectifier. Even if the lighting is turned off after work, the rectifier is still working in the charging state, so that the battery pack is fully prepared.

When the commercial power stops suddenly in an emergency, the inverter will automatically start the inverter circuit to convert the low-voltage electric energy of the battery pack into high-voltage electric energy and drive the light source to continue lighting.