Twilight Lamp Blinker

Twilight Lamp Blinker

It is very difficult to indicate any obstruction in day time. So to overcome this type of problem the team of dreamlover technology design a cirucit simple and inexpensive twilight lamp blinker,which blinks and can be used near obstructions.

Circuit Description of twilight lamp blinker

The entire circuit of twilight lamp blinker is designed and fabricated around LDR (Light Detector Resistor) and IC CD4093 (IC1). The preset VR1 is used to control brightness. For sensor LDR1 is used that has a high resistance during night (i.e. dark) and a low resistance at day time (i.e. light). The NAND gates (N3 and N4) of IC1 is used as oscillator where high input from NAND gate (N1) makes the output of NAND gate (N2) low and vice-versa. The high at NAND gate N2 result LED1 blinks by conducting transistor T1 where transistor T1 is the LED driver transistor. For more brightness more LEDs is connected parallel to LED1.


Resistors (all ¼-watt, ± 5% Carbon)

R1 = 10 KΩ/10W

R2 = 1 MΩ/1W

R3 = 100 KΩ

R4­ = 100 Ω

VR1 = 100 KΩ


C1 = 0.68 µF/400V

C2 = 100 µF/40V

C3 = 10 µF/35V


IC1 (N1 – N4) = CD4093

T1 = BC547

D1, D2 = 1N4007

ZD1 = 5.6V/1W

ZD2 = 15V/1W


LED1 = Blinker

LDR1 = Light Detector Resistor

Battery = 4.8 V/500 mAh battery pack

SW1 = SPST (Single Pole Single Throw)