Monday, January 4, 2016

81 LED chaser using double IC 4017

This circuit is LED chaser using double IC 4017 and IC 555 with 81 LEDs.
Flashing speed can change by potentiometer.
All transistors are 2N3904 but you can use any other NPN transistor.
Diode 1N4007 used for inverse power connection protection because IC 555 is very sensitive to - and + power supply reverse connection.
470 ohm resistor used for LEDs protection. you can use different color for each LED column.
The circuit can run by 3 x AA battery and power consumption is very low (about 10 to 20mA).

Parts list:
IC4017(2pcs)
IC555
2N3904(9pcs)
10k resistor(10pcs)
470 ohm resistor
3.3k resistor
LED(81pcs)
Capacitor 1uF 10v
100k potentiometer 
Diode 1N4007
1.5v AA battery(3pcs)

81 LED chaser using double IC 4017


81 LED chaser using double IC 4017