Table of Contents
About Sequential LED flasher using IC 4017, In this blog post, I will show you how to make a simple sequential LED flasher using IC 4017, a decade counter that can produce 10 different outputs in sequence. This circuit can be used for various purposes, such as decoration, signaling, or entertainment.
The main components of this circuit are:
- IC 4017: This is a decade counter that has 10 output pins (Q0 to Q9) that go high one by one in a cyclic manner when a clock pulse is applied to its pin 14. The clock pulse can be generated by a 555 timer or any other oscillator circuit. The output pins can be connected to LEDs or other devices that need to be switched on and off in sequence.
- Resistors: These are used to limit the current flowing through the LEDs and prevent them from burning out. The value of the resistors depends on the voltage supply and the type of LEDs used. For example, if you are using a 9V battery and red LEDs that have a forward voltage of 2V and a current rating of 20mA, you can use 330 ohm resistors for each LED.
- Capacitor: This is used to filter out any noise or fluctuations in the power supply and provide a stable voltage to the IC 4017. The value of the capacitor is not critical, but it should be at least 0.1uF.
- Switch: This is used to turn on and off the power supply to the circuit.
The circuit diagram of the sequential LED flasher using IC 4017 is shown below:
To make this circuit, follow these steps:
Connect the positive terminal of the power supply to pin 16 of IC 4017 and the negative terminal to pin 8.
Connect a capacitor between pin 16 and pin 8 of IC 4017 to filter out any noise or fluctuations in the power supply.
Connect pin 14 of IC 4017 to the output of a clock pulse generator, such as a 555 timer or any other oscillator circuit. You can adjust the frequency of the clock pulse by changing the values of the components in the oscillator circuit. The higher the frequency, the faster the LEDs will flash in sequence.
Connect pin 15 of IC 4017 to the ground to enable all the outputs. If you want to disable some of the outputs, you can connect pin 15 to any of the output pins that you don’t want to use. For example, if you want to use only four LEDs, you can connect pin 15 to pin Q4. This will make the outputs Q0 to Q3 cycle repeatedly and ignore the rest.
Connect one end of a resistor to each of the output pins (Q0 to Q9) that you want to use and connect the other end to the anode (positive terminal) of an LED. Connect the cathode (negative terminal) of each LED to the ground.
Connect a switch between the power supply and the circuit to turn it on and off.
You have successfully made a sequential LED flasher using IC 4017. You can experiment with different values of resistors, capacitors, and clock frequencies to change the brightness, speed, and pattern of the flashing LEDs. You can also use different colors and shapes of LEDs to create different effects. Have fun!
PCB for sequential LED flasher using IC 4017 and 555
Bom sequential LED flasher using IC 4017 and 55
Last update: 04/28/2023 19:35
| Part | Valor | Description | Quantity |
| Capacitors | |||
| C1 | 100n | Ceramic Capacitor | 1 |
| C2, C3 | 1uF | Electrolytic Capacitor | 2 |
| Semiconductors | |||
| IC1 | NE555 | Timer integrated circuit | 1 |
| IC2 | CD4017 | Decade counter integrated circuit | 1 |
| LED1 ~ LED10, | Led 5 mm | Red LED | 10 |
| Resistors 1/4W 5% | |||
| R1 | 2.2K | Red, red, red, gold. | 1 |
| R2 | 10K | Brown, black, orange, gold. | 1 |
| R3, R4, R5, R6, R7, R8, R9, R10, R11, R12 | 680 | Blue, gray, brown, gold. | 10 |
| Miscellaneous | |||
| P1 | 50K (503) | Trimpot vertical | 1 |
| CN1 | DC (Power) | 2.54 mm connector | 1 |
| Solder, Wires, PCB, Case, Power Supply, etc. | |||
Download the materials for this assembly
Printed circuit board (PCB) in Gerber, PNG, PDF, and PS formats
