Musical light circuit

Introduction

You might have experienced that in popular disco music programmes favourite pops or film pieces of music are being sung with fascinating dancing/psychedelic lights. The coloured lights dance to the tune of the music that is the lights blink fast or slow in accordance with the tune of the song. The lights go on rhythmic the music makes one enjoy the music. These dancing lights are normally called disco lights or psychedelic lights. The dancing lights boost the real feeling of the concert with high enjoyment. Usually, the younger generation people like very much to have these setups in their music concerts.  The music lovers sing, dance and enjoy the shows very much to their satisfaction. 

How do they achieve the rhythmic dancing of the disco lights in music concerts? A simple circuit like the one described here makes the show richer. As such one is interested to use such psychedelic circuits of their own for simplicity, low cost and manoeuvrability during the occasion to his or her taste. 

Musical light circuit building is an interesting project especially among hobbyists and students in their projects list. It is easier and simple to assemble such a utility-oriented circuit especially when it is presented with a ready-made PCB design. On the great demand for such type of circuit, a simple easy to build circuit design is explained here. 

Circuit schematic

The circuit utilises two NPN Silicon Transistors for amplifying the audio signal. 2N3020 transistors can handle large audio signals and amplify to drive 3 bulbs of 6V operation. With Proper heatsinks fixed to Q2, 3 more bulbs can be added to the circuit design.

The musical Light circuit schematic

Sound signal can be directly fed from the speaker to the input. Three bulbs can be connected in series to the positive power supply. Only one bulb is shown in diagram H1. All bulbs are plain and colour paper may be wrapped around the bulb for the required colour display. Potentiometer VR1 is a sensitivity control and can be adjusted such that all the coloured bulbs flash according to the rhythmic musical signal. 

The circuit design given here is for mono only. For stereo operation, two such circuits should be included for the set-up. 

Assembling 

It is very easy to build this circuit since very few components are needed. As such it is very compact and economical to build at a low cost.

Parts List

Q1,Q2 = 2N3020 NPN Silicon Transistors

D1= OA 85 Diode

R1=2.2K Ohm Resistor

R2 = 22K Ohm Resistor

VR1= 1K Ohm Potentiometer

H1 =6V Bulbs (3 nos.) - only one shown in the diagram

PS= 6V DC  

Working

The sound signal is directly fed from the speaker into Audio In. Adjust the Potentiometer VR1 such that all the coloured bulbs flash according to the musical signal. Bulbs give a dancing effect with a change in the intensity of brightness according to the musical sound fed into it. The number of bulbs can be increased if Power transistors are used with a suitable heatsink in the place of Q2. 

The sources of Power supply capacity i.e. amperage delivery should be suitably increased if more bulbs/lights are added to the circuit. 

PCB design

If one is interested to build this circuit on a printed board, a ready-made PCB design is given here. The circuit design can be etched on a copper clad board and etched for the preparation of a PCB of this type. 

PCB design full view

A full view of the PCB design of the circuit schematic is given for ease of understanding the board as well as for the assembling guide. 

Input audio signal is given to the points L1 & L2. The bulbs should be connected between points A&B. B is connected to the +ve terminal of the power supply.

To sum up

As youngsters like the circuit design very much, it is popularly claimed with school/college students and electronics learners.  Please share the circuit design with your friends and relatives for a useful and enjoyable project in electronics.