A simple buzzer is an electromagnetic device that generates sound when an electric current flows through it. It consists of a coil of wire (an electromagnet) and a diaphragm or a small piece of material that vibrates to create sound waves. Here's how it works in an electrical circuit:
Electromagnet: The core component of a buzzer is an electromagnet. This is typically a coil of wire wound around a cylindrical core made of a magnetic material like iron. When an electric current passes through the coil, it creates a magnetic field around the core.
Diaphragm: Attached to the core of the electromagnet is a diaphragm, which is usually a thin, flexible piece of material such as metal or plastic. The diaphragm's purpose is to vibrate when subjected to the magnetic force generated by the electromagnet.
Contact Points: The diaphragm is positioned close to the core but not in direct contact with it. There is a small gap between the diaphragm and the core. In some buzzers, this gap can be bridged by a movable contact or armature.
Circuit: The buzzer is connected in an electrical circuit. The circuit typically consists of a power source (e.g., a battery), a switch (which can be a physical button or an electronic component), the buzzer itself, and a resistor (to control the current flow if needed).
Activation: When the circuit is closed (the switch is turned on), current flows through the coil of wire in the electromagnet. This current generates a magnetic field around the core.
Magnetic Attraction: The magnetic field created by the current flow attracts the diaphragm or the armature towards the core of the electromagnet. As the diaphragm moves closer, it may make contact with the core or the armature, closing the gap between them.
Vibration: When the diaphragm or armature makes contact with the core, the attractive force diminishes, causing the diaphragm to move away from the core due to its inherent flexibility. As it moves away, the magnetic attraction increases again, causing the diaphragm to move back towards the core. This cycle of attraction and repulsion repeats rapidly.
Sound Generation: The rapid movement of the diaphragm back and forth causes it to vibrate at an audible frequency. These vibrations create sound waves in the surrounding air, producing the characteristic buzzing sound.
Continuation: As long as the circuit remains closed and current flows through the coil, the diaphragm will continue to vibrate, generating a continuous buzzing sound. When the circuit is opened (the switch is turned off), the current stops flowing, and the magnetic field dissipates, causing the diaphragm to stop vibrating and the sound to cease.
In summary, a simple buzzer works by utilizing the principles of electromagnetism to rapidly vibrate a diaphragm, generating audible sound waves when an electric current flows through the circuit.