Electromagnetic buzzer: the difference between electromagnetic buzzer and piezoelectric buzzer and driving method
Electromagnetic Buzzer Passive Buzzer is a common pronunciation electronic equipment when designing electronic equipment. According to the principle, it can be divided into induction manual buzzer and piezoresistive manual buzzer. The common passive buzzer in the microcontroller development board and the experimental board is an inductive passive buzzer.
Fuhongda recommends the difference and driving method between electromagnetic buzzer and piezoelectric buzzer:
1, principle of induced manual buzzer
The speaker induction manual buzzer is composed of electromagnetic coil and ceramic diaphragm. Appropriate working voltage is applied on both sides of the electromagnetic coil. When current passes through the electromagnetic coil, electromagnetic field will be generated, the electromagnetic field can deform the ceramic diaphragm. If a varying amount of current is presented, the passive buzzer will sound. Rechargeable battery-type passive buzzers can be divided into active buzzers and passive buzzers, depending on whether there is a fluctuation source inside.
Buzzer There is a fluctuation source inside the active buzzer, and only appropriate working voltage needs to be added to both sides of the electromagnetic coil. There is no fluctuation source inside the passive buzzer, so it is necessary to use a waveform to drive from the outside. Changing the waveform frequency will change the noise.
2. Principle of Piezoresistive Passive Buzzer
Piezoelectric passive buzzer works by piezoelectric effect. Passive buzzer is composed of piezoelectric ceramic sheet and ceramic diaphragm. After the power supply is connected to the piezoelectric ceramic sheet, the piezoelectric ceramic sheet changes and the driving ceramic diaphragm is deformed. After the working voltage is eliminated, the ceramic diaphragm returns to the original deformation. Therefore, the manual buzzer can be pronounced if the transferred operating voltage is applied only to both sides of the pressure ceramic sheet. Ultrasonic components are also completed using this basic principle.
3, the difference between the two
The main difference between the structure types of electric shock passive buzzer and piezoresistive passive buzzer is solenoid and piezoelectric ceramic sheet. Inductive manual buzzer Due to the presence of the solenoid, the solenoid instantly forms a peak, which may harm the actual effect of the tone. Since the pressure resistance type passive buzzer has no electromagnetic coil, there is no danger of normal single pulse. In addition, the noise decibel of the piezoresistive manual buzzer is proportional to the working voltage, and the rated voltage is usually higher than that of the inductive manual buzzer.
4, two drive methods
The two drivers have similar methods, and the triode can be applied to the driver. In the case of passive passive passive buzzer, the driver needs to add a backfill diode, and no active buzzer or piezoelectric buzzer is required.
above is the content collected by Changzhou fuhongda electronics co., ltd. if necessary, please contact us.
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