LED Chaser Circuit using IC 4017

This LED Chaser Circuit using IC 4017 project make LED lights turn ON one by one like chasing, also it is fun way to learn electronics.

In addition, one chip of IC 555 makes pulse again and again and that pulse connects to other chip IC 4017 and it turn ON and OFF each pin one by one.

Furthermore, all pins connect to LED so LED blink one after other and we can change speed of LED chase by turning one knob of potentiometer.

Moreover, the circuit work with 12V battery and is good for beginners and we can learn how, two important chips work, like small course to show how LED lights in order.

What is a LED Chaser Circuit using IC 4017:

LED chaser circuit with IC 4017 is very popular and easy project, which make nice light effect by turning ON and OFF LEDs one by one like chasing.

Furthermore, the IC 4017 also called a decade counter, is a useful chip that designers commonly use in LED chaser circuits.

Circuit Working:

Parts List:

Components	Values	Quantity
Resistors	1k 1/4 watt	11
	10k 1/4 watt	2
	Potentiometer 100k	1
Capacitors	PPC 0.01µF	1
	Electrolytic 10µF 25V	1
Semiconductors	IC 4017	1
	IC 555	1
	LEDs 5mm 20mA	11
	Power supply +12V	1

Firstly, IC 555 work as astable multivibrator that mean it make square wave pulse again and again without stopping.

Connect a 100k potentiometer between the positive supply and pin 7 of the IC and connect the wiper (middle pin) and the upper pin to the positive supply through a 10k resistor.

Hence, this help to change voltage on pin 6 so it can change how fast IC 555 make pulse.

Furthermore, the IC 4017 functions as a decade counter and has 10 output pins (pin 3 to pin 11) and we connect pin 14 (clock input) of the IC 4017 to pin 3 (output) of the IC 555.

So every time IC 555 send a pulse IC 4017 connects to next output pin.

Also, 10 LEDs connect to output pins of IC 4017 and when clock pulse come IC 4017 turn ON each LED one after one and this makes LED chasing or running light effect.

Thus, knob potentiometer in IC 555 part control speed of pulse and when we turn knob it changes how fast capacitor charge and discharge in IC 555 and that changes the pulse speed.

Finally, LED chase goes fast or slow depending on knob setting.

How circuit works:

Here, IC 555 make square wave signal again and again and knob changes how fast it make.

Also, this signal goes to IC 4017 clock input and IC 4017 turn ON each output in order.

Then LEDs are connect to these output pins so they light up one by one like chasing and also whole circuit uses 12V DC power.

Speed Control:

We can turn knob to make LED go faster or slower and this knob changes the resistance and that change the timing in IC 555.

More resistance = slower chase and Less resistance = faster chase.

Formulas:

Below are the formulas for LED Chaser Circuit:

1. Frequency of IC 555 Astable Multivibrator:

This show how fast IC 555 make square wave signal.

Formula:

f = 1.44 / (RA + 2 × RB) × C

where:

• f is the frequency in Hertz Hz
• RA is the resistor which connect to pin 7
• RB is the resistor which connect to pin 6 and 2
• C is the capacitor that connect to pin 6 and 2

Thus, this formula tell how fast LEDs will blink one by one.

2. LED Current Limiting Resistor:

Each LED needs a resistor so it does not burn.

Formula:

RLED = VR / ILED

where:

• VR is the voltage from 12V minus LED forward voltage
• ILED is how much current LED should get

Hence, use this this formula to keep LED safe.

How the Circuit is Build:

To build a LED Chaser Circuit using IC 4017 follow the below steps for connections:

IC 555 Connections:

• First, gather all the circuit parts.
• Next, pin 1 connects to ground.
• Then pin 2 connect with resistor to pin 6 and capacitor to ground.
• After that, connect pin 3 to pin 14 of IC 4017 the clock input.
• Next, pin 4 and pin 8 connect to VCC of positive power.
• Then pin 5 connect to ground with 0.1µF capacitor.
• After that pin 6 connect to one side of 10k resistor.
• Also, pin 7 connect to one end of 100k potentiometer knob.

IC 4017 Connections:

• First, pin 8, 13 and 15 connects to ground.
• Then pin 16 connect to 12V power.
• After that, pins 3 to 11 are output pins which connects each to one LED.
• Next, anode of LED long leg connects to IC 4017 output pin 3 to 11 and cathode of LED short leg connects to ground through 1k resistor.

Notes:

• First, use correct resistor so LED does not get too much current.
• Also, double check IC pins and LED direction before power is ON.
• Remember to turn potentiometer to change speed of chasing LED effect.

Conclusion

To conclude, this easy LED Chaser Circuit using IC 4017 first should try it on breadboard before making permanent on PCB.

Also, always be careful when working with electric circuits and safety should be first and for more details we can look at datasheet of the ICs and learn how the circuit work.