This Circuit is based on Timer IC555 & IC4017. The 555 Timer IC sends a clock pulse to the 4017 Counter IC. The counter IC counts and sends a signal to the next output pins. There are a total of 16 pins in the 4017 IC. out of them, 10 pins are output pins (Output Pin No. 3,2,4,7,10,1,5,6,9,11) and pin no 15 is Reset pin. When it completes 10 counting’s, it again counts from 1st pin.
But in this circuit we are using only 3 output pins Pin no 3,2 and 4 and reset the 4th output pin no 7 with IC Reset Pin (Pin No. 15).With same method you can use output pins as per your need. Example if you need 6 channel chaser you can use pin no 3,2,4,7,10,1 as output pins and reset pin no 5 with pin no 15. You can make 3-10 output led chaser lights as per your need just changing the reset pin connection.