The LED chaser or sequencer is one of the most mainstream kinds of LED driving circuit and is generally utilized in advertisements and in running-light ‘rope’ displays in little discos, and so on.
The figure beneath shows a fascinating circuit of a 20 LED sequencer or chaser utilizing a 555 timer and two CD 4017-decade counter ICs. This circuit is perfect in the event that you want more LEDs to make a shape around which the LEDs will run in the arrangement. For instance, a heart shape or other comparable shapes, you can simply utilize it to make simple pursuing impacts with numerous LEDs. The blinking sequence sets apart with numbers on the LEDs. You can likewise utilize transistors at each yield to drive more LEDs on each yield output. The circuit can likewise be utilized for some other pulse generator purposes.
Hardware Components
The following components are required to make LED Sequencer Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Photocoupler | PC817 | 1 |
| 2. | IC | NE555 Timer | 1 |
| 3. | Decade counter IC | CD4017 | 2 |
| 4. | LEDs | – | 20 |
| 5. | Variable Resistor | 100K | 1 |
| 6. | Electrolytic Capacitor | 10µF | 1 |
| 7. | Ceramic Capacitor | 0.01µF | 1 |
| 8. | Resistor | 2.7KΩ, 1KΩ, 390R | 1, 1, 3 |
| 9. | Battery | 5V – 12V | 1 |
CD4017 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of CD4017
NE555 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of 555 Timer
PC817 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of PC817
LED Sequencer Circuit
Working Explanation
The circuit is utilizing 3 ICs. The 555 timer IC with photocoupler is utilized to give a positive pulse to both the ICs individually. The speed of the pulses or pursuing speed can be increment or decline with the 100K variable resistor. The circuit can work with 5V to 12V DC.
The CD4017 is an adaptable and simple to-utilize IC and has impeded yields that display marginally amazing attributes when driving LED-type loads. The figure shows CD4017 circuits that can be utilized to exhibit the IC’s fundamental actions and output driving characteristics.
Applications and Uses
The chaser or sequencer is one of the most famous kinds of LED-driving circuits and is generally utilized in the following:
- Advertising displays
- In running-light ‘Rope’
- Displays in small discos, and so forth.
