Sometimes happen in the absence of light, we can’t operate any device due to darkness.
So here is a simple automatic on/off lamp circuit.
The shown device is able to switch ON automatically when mains power fails. This simple emergency lamp circuit uses very components and yet is able to, illuminating all the connected LEDsas soon as power is restored, the LEDs shut off automatically and the connected starts charging through the built in power supply. The circuit employs a transformer less power supply for initiating the explained automatic actions and also for trickle charging the connected battery.
NOTE- Be carefully, AC 230v is used as Input Components-
R1 = 220K
R2 = 10K,
D1, D2, D3 = 1N4007,
Z1 = 15V 1watt, Zener diode,
C1 = 105uf/400V
C2 = 100uf/25V
T1 = 2N2907, or 8550, or BD 140
Z1 = 12V, 1 watt
LEDs = white, High brightness