1、 Composition of electromagnetic buzzer:

Vibration device

When there is current passing through the coil, the vibrating device will vibrate due to changes in magnetic energy, causing the position of the vibrating piece to change.

a. The electromagnetic energy generated by the current is actually very small, making it difficult to drive the vibrating plate to work normally. Therefore, another magnetic field, interference, control, and superposition of the magnetic energy of this magnetic field are needed; Obtain mechanical compliance)

b. The superposition of magnetic energy increases the magnetic attraction of the vibrating plate, forcing it to shift, compress the air, and produce sound;

c. The vibrating plate vibrates unidirectionally in the direction of the coil, and the number of vibrations is controlled by the signal frequency. The amplitude is proportional to the input power;

resonance device

a. The transmission of vibration energy is completed by magnetic attraction, so the distance between the vibrating plate and the magnetic pole is designed to be limited (about 0.1-0.2). The amplitude of the vibrating plate is small (about 0.05mm), and the sound emitted is very low. Therefore, a resonant cavity should be used to fully resonate the vibration sound (resonate) to achieve resonance effect (amplify the sound).

b. Due to the relatively strict frequency response of the resonant cavity, the resonant frequency amplitude is narrow and the frequency response range is small.