A simple buzzer is an electroacoustic device that produces sound when an electrical current is passed through it. It's commonly used in various applications like alarms, timers, and notification systems. Here's how a simple buzzer works in an electrical circuit:
Electromagnetic Coil: The core component of a buzzer is an electromagnetic coil. This coil is typically made of a thin wire wound around a central core. When an electric current flows through the coil, it generates a magnetic field around it.
Armature or Diaphragm: Inside the buzzer, there is an armature or diaphragm, which is a thin piece of metal or plastic that is free to move. The armature is placed close to the electromagnetic coil but is not physically attached to it.
Contact Points: The armature is equipped with a contact point, and there's another fixed contact point within the buzzer, connected to the other terminal of the coil. These contact points act as a switch that opens and closes as the armature moves.
Power Supply: When the buzzer is connected to a power supply, such as a battery or a power source in an electrical circuit, a current flows through the coil. This current creates a magnetic field around the coil.
Magnetic Attraction: The magnetic field generated by the coil attracts the armature towards the coil. As the armature gets close to the coil, it closes the contact points, completing the electrical circuit.
Circuit Completion and Sound Generation: When the contact points close, the current flows through the coil and the armature, creating a stronger magnetic field. This enhanced magnetic field holds the armature in place against the coil with a force. However, as the armature is attached to the diaphragm, it moves the diaphragm closer to the coil as well.
Vibration and Sound: The movement of the diaphragm creates a change in air pressure, generating sound waves. These sound waves are what we hear as the buzzing or humming noise produced by the buzzer. The rapid opening and closing of the contact points due to the vibration of the armature lead to a repeated cycle of sound production, resulting in the characteristic buzzing sound of the buzzer.
Cycle: As long as the electrical current flows through the coil and the contact points continue to open and close due to the movement of the armature, the buzzer will keep generating sound.
It's important to note that the sound frequency and volume of the buzzer can be influenced by factors like the design of the coil, the materials used in the diaphragm, and the specific properties of the circuit components.