Sound to Light Meter




Introduction: Sound to Light Meter

I started making this circuit as I was in the process of making an operational amp for a Pringle tub Speaker system which I actually really enjoyed using and making and wanted to incorporate lights into is as a portable all around music system.

This is the prototype VU meter on a breadboard powered by a 9v battery.

Here it is>

I was very proud of this as it took a lot of research as I was fairly new to electronic circuits at this time.

Step 1: Learning What Is What

When researching I came across the Vellemans website and upon it I found the Pocket VU meter circuit with it the above schematics. This is not the one I chose but the one I learnt from.

Although they do sell the kits which are brilliant if you want to just have it now I tried to understand why the circuit was made and why each part was needed so I set out to find out the facts of each part used and how it operated.

I would like to save you some time if you are planning on taking the same path as myself or already have knowledge. The BC547 is a simple small use NPN transistor and the Input was a 2 pin Electret Condenser Microphone.

Also BAT85 is a 113 Small Signal Schottky Diode, Single, 30 V, 200 mA, 800 mV, 5 A, 125 °C as informs me.

Once I had understood what was what the Vellemans circuit was a good starting point but

I WANTED MORE LIGHTS DAMMIT!!!!!!!!!!!!!!!!!!!!!!

Step 2: Chosen Schematics

Credit for this circuit schematics is given to as I found their schematics on Google and found it easy to follow with a few helpful tips. Thank you talking electronics.

I chose this schematics for the main purpose of increased LED output and the ease of building.

It was build at night after a days work and with tiredness some problems of crossed wires did occur but after a good night sleep they was obvious and easy to spot.

The next step would be to incorporate this circuit with a few relays and this could be adapted to control mains powered lighting to create a larger and brighter display.

Hopefully you will use this to light up your project like this will do to mine.

Thank you for reading.

Epilog Contest VII

Participated in the
Epilog Contest VII

Be the First to Share


    • Pocket-Sized Speed Challenge

      Pocket-Sized Speed Challenge
    • Audio Challenge 2020

      Audio Challenge 2020
    • Maps Challenge

      Maps Challenge

    2 Discussions


    4 years ago

    here 3 variables A B and C how can I attach a mic on 3 inputs .. (A for positive and B , C of negative ??)


    4 years ago

    Both schematics work fine.

    Two quad comparators driven by a couple of transistors or an opamp will do the job, I would say more "elegantly".