Buzzer

An electromagnetic buzzer is a device that produces sound using the principle of electromagnetic induction. It is divided into two types: active (with a built-in oscillator that sounds when powered by direct current) and passive (requiring an external square wave drive). They are small in size and generate a magnetic field through a coil, which attracts or repels a permanent magnet to drive the diaphragm to produce sound. They are commonly found in home appliances, medical equipment, and electronic toys where prompts are required.

A mechanical buzzer is an electronic component that produces sound using mechanical principles. It mainly consists of a diaphragm, coil, and magnet. It produces sound by vibrating the diaphragm through electromagnetic induction and is commonly used in devices such as alarms and doorbells to emit alert sounds.

A piezo buzzer is an electronic component that uses piezoelectric materials (such as PZT) to produce sound by generating mechanical vibrations when stimulated by voltage. It is commonly found in birthday cards, toys, or electrical alarm sounds, and is divided into two types: self-excited and externally driven.