Share an interesting LED decoration project

LED Chakra is a decorative lighting system that depicts or mimics the appearance of a spinning wheel through an array of light-emitting LEDs that move in sequence.

The Indian subcontinent is a land of festivals and celebrations that mainly start in August and continue till the New Year. All these festivals have one basic thing in common, which is the dazzling colorful lights that flash in various patterns and sequences. Most of these lights are in the form of LED lights as LEDs are the most efficient in terms of brightness and cost.

In this article, we will discuss one such interesting LED decoration project that will mimic the spinning illuminated chakra lamps. These can be seen behind the crowns of popular God idols like Lord Ganesha, Sai Baba, and around the fingers of Lord Vishnu.

Working Theory

The working principle of this LED Chakra circuit is based on the popular IC 4017 and IC

555 chase circuit. The only difference is in the output driver stage which has been upgraded to a delayed OFF timer stage to introduce an attractive slow fade effect.

The slow fade-in and fade-out effect induces the persistence of visual effects that we usually experience in real-life rotating devices such as fans, motors, wheels, etc.

This allows the LED Chakra to achieve a real shiny spinning metal effect when placed behind the God idol.

Circuit Description

As mentioned above, the design is adapted for IC 4017, which is Johnson's 10-stage decade counter divider IC, and IC 555, a basic astable multivibrator.

IC 555 oscillates at a rate of about 50 to 100 Hz (adjustable) and provides the required clock pulses to pin #4017 of IC 14 .

IC 4017 converts the clock into momentary conduction, switching high logic on its output pin.

These shifted logic levels are fed to the array's delayed turn-off transistor stage, which keeps the sequence firing for a moment, rather than shutting off immediately.

This enables the corresponding transistor stage to keep the LED lit for a certain period of time and provide the desired spinning chakra effect, with time lag.

Parts List

All resistors are 1/4 Watt 5%

10K - 10

22K - 10

33K - 1

100K or 330K Potentiometer - 1

Capacitors

0.01uF - 1

0.1uF - 1

1uF/25V - 1

33uF/25V - 10

semiconductor

1N4148 - 10

BC547 - 10

LED - 40

Integrated Circuits 4017-1

Integrated Circuit 555-1