stairwells and evacuation walkways should be equipped with emergency lighting.

evacuation emergency lighting and sign lights, collectively referred to as fire emergency lighting, are an important product required by fire safety measures. At ordinary times, it should provide lighting like ordinary lamps. In case of emergency, such as earthquake, fire or circuit failure, when the power supply is suddenly interrupted, all light sources have stopped working. At this time, it must immediately provide reliable lighting and indicate the direction of evacuation and the location of emergency exits to ensure the smooth evacuation of people stranded in the dark.

It can be seen that emergency lighting is a light source to keep lighting and guide evacuation in an emergency.

brief introduction of working principle

the circuit principle of the emergency light. Power transformer T1, rectifier diodes VD1~VD4, C1, R1, VD5 and VD6 form a charging and power supply indicating circuit; VT.T2, R2, C2, VD7, R3 and C3 form an LC self-excited oscillation circuit; SA1 is used to connect the power supply of the oscillation circuit; C4 is the filter capacitor.

when the commercial power supply is normal, the 221V AC voltage is reduced by T1, rectified by VD1~VD4 and filtered by C1, and then a DC voltage of about 14V is obtained, which is charged to the 12V battery through the isolation diode VD6. At the same time, the indicator lamp VD5 lights up, indicating that the mains power supply is normal.

after the mains power fails, the indicator lamp VD5 goes out. If lighting is not needed during the day, it is not necessary to close SA1, the oscillation circuit will not work and the emergency light will not light up; When lighting is needed at night, SA1 can be turned on, the oscillation circuit starts to vibrate, and the emergency light is lit.