LED Chaser Using NE555

Various types of LED based projects is already posted on bestengineeringprojects.com.  Now, here is a simple project called LED chaser using NE555 in which 10 different LED is arranged in column. The LED arranged in column glow from top to bottom, one at a time.

Circuit Description of LED Chaser Using NE555

The circuit of LED chaser is designed around a timer IC NE555 (IC1) and decade counter IC CD4017 (IC2). Here, IC1 is used in astable multivibrator mode which generate a clock pulse in fixed interval of time. The clock from pin 3 of IC1 is given to the pin 14 of IC2 which count each clock pulse and reset after each 10 clock pulse. Only one output out of ten of decade counter is high i.e. nine outputs is always low. Preset VR1 is used to adjust the clock pulse of IC1.

circuit diagram of LED chaser


Resistor (all ¼-watt, ± 5% Carbon)
R1, R2 = 1.5 KΩ

VR1 = 100 KΩ

C1 = 1 µF/16V

C2 = 10 µF/16V

IC1 = NE555

IC2 = CD4017 BE

LED1 – LED10