Views:5 Author:Site Editor Publish Time: 2021-05-08 Origin:Site
Piezoelectric ceramic disc, commonly known as buzzer chip, is an electronic sound element. A piezoelectric ceramic dielectric material is placed between two round copper electrodes. When an AC audio signal is connected to the two electrodes, the piezoelectric plate will vibrate according to the magnitude and frequency of the signal to produce a corresponding sound. Piezoelectric ceramic sheets are widely used in electronic appliances such as toys, pronunciation electronic watches, electronic instruments, electronic clocks, timers, etc. due to their simple structure and low cost.
When a piezo ceramic disc is applied with a DC voltage, it produces alternating and repeated mechanical bending deformations, thereby generating sound waves in the air. Under the action of external force, the piezoelectric ceramic sheet generates electric waves, which are converted into electric signals.
High sensitivity, low energy consumption, good reliability, good stability, high and low-temperature resistance, long life, thin thickness, lightweight, small size, high-pressure resistance, etc.
Sensor electronic sphygmomanometer
A piezoelectric buzzer is a sounding body that uses piezoelectric ceramics as an electro-acoustic transducer. The core of this type of device is a transducer made of a piezoelectric ceramic wafer pasted on a metal sheet, that is, a piezoelectric buzzer sheet. The characteristics of a piezoelectric buzzer without radio frequency noise and low power consumption make it highly regarded and developed very rapidly.
The piezoelectric buzzer is mainly composed of a multivibrator, a piezoelectric buzzer, an impedance matcher, a resonance box, and a shell. The multivibrator is composed of transistors or integrated circuits. When the power is turned on (1.5~15V DC working voltage), the multivibrator starts to vibrate and outputs 1.5~2.5kHZ audio signals, and the impedance matcher drives the piezoelectric buzzer to sound.
The preparation process of the piezoelectric buzzer mainly includes batching, ball milling, spray granulation, molding, sintering, and post-processing. Among them, the molding process is a very important process in the preparation process. It not only affects the size and shape of the tube, but also affects the uniformity of the microstructure of the molded body and the uniformity of the phase distribution according to the different molding methods, and then affects the sintering process and directly affects the quality of the product.
Therefore, the dry pressing method is generally used. In terms of sintering, the use of medium and low-temperature firing is a process designed to prepare high-quality PZT piezoelectric ceramic buzzer products under the principles of safety and reliability, attention to environmental protection, reasonable consideration of mechanization, automation equipment level, and economy.
Drive mode: If the frequency signal cannot be provided for the buzzer to work, consider using the built-in drive circuit and apply DC voltage. There are also different sound signals such as straight tone, fast tone, and slow tone. (There are two methods: self-excited oscillation is a way to generate sound waves using the oscillation at the resonance point; other-excited oscillation is a way to generate sound waves at a frequency far away from the resonance point.)
Size: Size will affect the frequency, small size will have a higher frequency.
Voltage: Calculated by V O-P, driven by a square wave, the higher the voltage, the higher the volume.
Pitch: Piezoelectric buzzers have many specifications, and it is often difficult to find exactly the same specifications. You can choose the same pitch and close frequency for the trial.
(1) Because there is no movable contact part, it has a long life and high reliability. It can be used continuously for more than 10,000 hours. It is a semi-permanent device.
(2) No arcing or radio frequency noise is generated, and no interference to other lines.
(3) Will not cause big vibration due to looseness.
(4) It is controlled by the electronic circuit, so it can emit a variety of pleasant sounds, analog sounds, and intermittent sounds. The tone is pure and not easily covered by noise.
(5) With voltage excitation, the current consumption is small, generally below 20mA, not more than 100mA.
(6) Small and large volume, the volume can reach 70 decibels/20cm, and the thickness of the component is only 1mm or less.
(7) Wide operating temperature range.
(8) It is easy to install, and there is no electromagnetic coil and moving coil, so there is no need to worry about insulation deterioration, and there is no possibility of leakage.
Piezoelectric buzzers actually have three commercial forms, namely, the piezoelectric buzzer complex, a piezoelectric buzzer sounding body, and a piezoelectric buzzer, to meet different needs in the market. Regardless of the form, its use is inseparable from the three types of alarm, judgment, and notification.
The piezoelectric buzzer for alarm is used for fire, smoke density, air leakage, anti-theft, and automobile alarm. The piezoelectric buzzer for notification is used as notification in fish hunting machines, instruments, medical equipment, vending machines, washing machines, electric stoves, etc., and is more advantageous than light indications. In addition, the piezoelectric buzzer with analog sound and composite sound can also be used in toys, video games, and so on.