In this post, it’s shown the operation of integrated circuit 4017, from CMOS family. In addition to some projects which are possible to make with this chip.
Chip operation and interior
Decription of 4017 pins.
- Vdd and GND: Supply and ground terminals, respectively.
- CLK: Clock terminal, which must receive a square wave.
- EN: Clock inhibitor.
- Reset: If it’s linked to GND, will restart counting when the output go to 10. When it’s on level “1”, restart counting immediately.
- Carryout: Goes from “Low” to “High” state when chip counts to 10.
The 4017 is a Johnson counter, or ring counter, with 5 type D flip-flops. In this counter, the last flip-flop’s inverted output is linked to the first one’s D input. The outputs in this type of counter show a pulse of “high” values.
Chip outputs change in sequence to “1” level due to logic doors NAND and NOT, at top of the logic diagram, which form a combinational circuit.
Some projects with 4017
This integrated circuit has many applications, in this post is shown a small part of what can do with the component.
LED Chaser
In this circuit, 10 LEDs light up in sequence one at a time. Then, starts again. An astable 555 provides a clock signal for 4017.
Needed materials:
- 1 CD4017BE.
- 1 555.
- 10 LEDs of any color.
- 1 47 μF electrolytic capacitor.
- 3 resistors: 1 of 470 Ω, 1 of 3,3 kΩ, and 1 of 5,6 kΩ.
- Wires.
The schematics on KiCad.
The LED Chaser assembled in PCB.
Cylon eye
In this circuit, The light of LEDs goes and returns. Has this name because reminds Cylon’s red eye from Battlestar Galactica.
Schematics and material list respectively.
- 1 NE555P.
- 1 CD4017BE.
- A 22 μF electrolytic capacitor.
- 6 LEDs of any color.
- 3 resistors: 1 470 Ω, 1 3,3 kΩ and 1 5,6 kΩ.
- 10 1N4007 diodes.
The diodes allow LED light to “return” because leads the current and block passages to previous outputs. Note that LEDs of extremities use only a single diode.
Color chaser RGB
It’s a LED Chaser adjusted with 3 potentiometers. Since RGB LED has 4 terminals, the circuit has 3 LED chasers. A video of three projects in operation.
