Doorbell Control Porch Light Using Timer IC (NE555)

This doorbell control porch light using timer ic (ne555),can be used in doorbell in order to get indication of porch light with door alarm if any one rings the door bell.

Doorbell Control Porch Light Circuit Diagram:

Doorbell Control Porch Light Circuit Diagram:

The circuit of doorbell control porch light is build around timer IC NE555 (IC2) and is here used as astable multivibrator. The output at pin 3 goes high of IC1 when trigger is given to pin 2 from power supply. Here transistor T1 is used as relay driver transistor which energized relay when output from pin 3 of IC1 is high. After relay energized AC current flow via N/O terminal and switch on the porch light.

Triac1 with Diac1 hear is used for switch in order to glow porch light during night and switch it off at day with the help of preset VR1 and LDR1.

Note:- Here the power source of 230V AC is replaced by 110V with replacing transformer having primary 110V and secondary 12V. Rest of the circuit  of door bell controll porch light is same.


Resistors (all ¼-watt, ± 5% Carbon)
R1 = 1 MΩ
R2 = 10 KΩ
R3 = 470 Ω
VR1 = 100 KΩ

C1 = 1000 µF/25V
C2 = 22 µF/25V

IC1 = NE555 (Timer IC)
T1 = BC548
DIAC1 = DB-3
TRIAC1 = BT136
D1, D2 = 1N4001


SW1 PUSH-TO-ON DPST (Double Pole Single Switch) Switch
B1 = Porch Light Bulb 100W
X1 = 230V AC primary to secondary 0-12V, 250MA secondary transformer
RL1­ = 12V, 200 Ω 1C/O relay

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