How to choose a piezo element buzzer suitable for the interior of the car

Inside the car, for example, the seat belt is not fastened to the driver's ear. It is necessary to obviously hear a kind of prompt sound. The prompt audio frequency does not need to be too high, so as to avoid causing the human brain to be irritable. The existing technology and frequency design of PZT piezo bimorph cannot meet the needs. Although the vibration frequency can be improved to 1000 Hz, the sound size cannot be guaranteed. The frequency of the conventional products of the electromagnetic buzzer is mostly 2048Hz or 2700Hz. The electromagnetic energy generated by the current is actually very small, and it is difficult to drive the vibrating piece to work normally. It is recommended to use an electromagnetic buzzer, which is stable and reliable, and the components include the bracket. , magnets, circuit boards, housings, coils and vibrating pieces, the vibration energy transmission is completed by magnetic attraction, so the distance between the vibrating piece and the magnetic pole is limited (0.2mm), the vibration is small, and the sound (0.1mm or so) is very low. The resonant cavity fully resonates (resonates) with the vibration sound to achieve the resonance effect. The design of this type of product can design the resonant cavity for the requiring vibration frequency to meet the needs of the sound frequency and the sound size. And the structure of internal drive piezo diaphragm is simple,it is very suitable for the sound prompt inside the car.