1 LED light chaser using 4017

This is a LED sequencer circuit where 10 led are lighting on and off after one another as if they are chasing each other .This simple circuit is  good in designing lighting   decoration in Christmas trees. This can be used in lighting animation by just adding more LEDs and drivers. The heart of the circuit is the 4017 decade counter that will give the lighting sequence in the LED. 555 timer serves as the master that gives the clock signal to the decade counter, and this ic controls the rate of the flashes depending on its output pulse frequency.

Led chaser schematic
4017 IC pins
Part List:
1- 555 IC
1- 4017b decade counter IC
R- 560 ohms (10pc)
10- LED (red, yellow, green, or orange)
R1,R3- 2k ohms resistor
R2- 20k potentiometer
R4- 1k ohms resistor
C1- 100nF capacitor
C2- 100uF electrolytic capacitor
battery 5V to 12V

You can change the rate of the flashes by just  adjusting the R2 pot resistor.  Full scale of pot is around 3 seconds light and delay in each led while zeroing R2 scale is around 400mS. Check the 555 timer calculator if you are planning to change the values of capacitor or resistor.

1 comments:

  1. I have a question about the led chaser circuit. The circuit shows a lead going from below R1 to the 555 IC, but does not show it connected to a pin number. Is it connected to pin 7? as this is the only pin that is not connected. Thanks.
    Richard

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