Sound components are divided into mechanical and electrical types. The mechanical type produces sound with the application of mechanical shocks to the sound source. This type is used, for example, in bicycle bells, other types of bells, gongs, and similar devices. The electrical type produces sound by vibrating the sound source part with the application of electrical signals such as voltage and current. The electric type is further divided into piezoelectric, electromagnetic (magnetic), and electrodynamic (dynamic) types.
This is a sound component for which a sound element (piezoelectric diaphragm) made by pasting together piezoelectric ceramics and a metal plate is embedded into a resonator (for example, a plastic case, etc.).
The piezoelectric diaphragm vibrates with the input of AC signals into a piezoelectric element, generating sound.
The electromagnetic type uses a diaphragm and electromagnet embedded in a resonator to generate sound by vibrating the diaphragm with changes in the magnetic field of the electromagnet.
The electrodynamic (dynamic) type uses a magnetic field generated by a coil with input signals to vibrate a cone and thereby generate sound.