Magnetic Effect on Sound

What have I made?

I’ve made a simple Active Buzzer Circuit to check whether magnetism has an effect on the buzzer’s beep frequency.

Why have I made it?

To check whether magnetism has any effect on sound.

Hope you've watched the video and observed what happens when the magnets are brought closer to the Active Buzzer in case of the different polarities.

Why does this happen?

First, the inside of an Active Buzzer Module consists:

• a piezoelectric disk that vibrates when a voltage is applied.
• three metal fingers on the PCB make contact with the disc.
• a little transistor amplifier is on the printed circuit board.

The Explanation is simple: A voltage is recieved, the piezoelectric disk vibrates. This vibration produces sound.

As eletricity passes, there is a magnetic field around the circuit.

When the magnets are introduced near the Buzzer, it affects both the magnetic field of the circuit and hence the vibration, leading to the change in frequency.

Active Buzzer, Battery, Breadboard, Neodymium Magnets.

Make the Active Buzzer Circuit.

Connect the Active Buzzer to the battery source either directly or by using a breadboard.

Slowly, bring your magnets towards the Buzzer. Active buzzer normally produces a continuous beep of approximately 2300 Hz at a voltage of 5V. But now as magnet approaches the buzzer, it either produced a higher frequency beep or a lower with opposite polarity approaching it

At a point even the beep sound drops to mute, may be the frequency in that case dropped below human audible range.

We observe that the frequency changes as the polarity changes and the sound level too, depending on the proximity of the magnet.

By giving a varied pattern of motion of magnet to and fro the buzzer, you can even create a music !!

Do try and enjoy !