A conventional electromagnetic products buzzer How does it work?
Passive Electromagnetic buzzer working principle is: through the exchange of signals around the stent on the line in support of the package have a core pillar of the alternating magnetic flux, and flux of alternating magnetic ring constant flux for overlay, so that Mo Tablets given to the exchange of signals with the frequency of vibration and sound cavity. Products throughout the frequency and sound pressure response curve with the value gap, molybdenum natural vibration frequency of on-chip (refraction can be rough for small film thickness of molybdenum), Shell (Helmholtz resonance Tune) frequency of the magnetic ring magnetometer Wire Is directly related to the diameter.
Second, conventional passive electromagnetic buzzer products from which materials?
Serial number Name
1 Stent
2 Line package
3 Magnetic ring
4 Plastic Block
5 Printed Circuit Board
6 Mo film
7 Shell
Third, conventional piezoelectric buzzer products How does it work?
Piezoelectric film buzz is very high-pressure after the piezoelectric ceramics adhesive vibration in the metal-on-chip. When the AC voltage added, because of piezoelectric effect, and the generation of mechanical stretching deformation and shrinkage of the use of the properties of metal so that the vibration and sound
1, peripheral support – will buzz film at the outer edge of fixed-cavity resonance, not to adopt the general feedback buzz-on-chip, and its buzz with film resonator with frequency, there will be a higher sound pressure output By an external circuit to generate promote the oscillation signal, so that the buzzer sounds.
Node support – will be fixed on the buzz about films with the ceramic piece with a diameter the size of the ring structure. If properly designed cavity, and with the correct frequency of feedback-film buzz with the feedback circuit is, will be able to generate higher sound pressure and the right frequency.
Fourth, conventional passive piezoelectric buzzer (external drive) from which the material composition of the product?
Serial number Name
1 Shell
2 Film buzz
3 Wire
4 PCB assembly
PCB fixed passive piezoelectric
Spring needle passive piezoelectric buzzer
Fifth, active and passive buzzer buzzer What’s the difference?
Active and Passive buzzer buzzer is a fundamental difference between the product of the input signal does not require the same;
Buzzer active work of the DC is the ideal signal, usually marked as VDC, VDD, and so on. Buzzer because there are a simple oscillator circuit, to the constant direct current into a certain frequency of the pulse signal from the plane is out of alternating magnetic field, Mo-led film sound vibration. However, some active at the buzzer specific signal exchange for being able to work only on the exchange of signals in the voltage and frequency of demanding that such work will not be adopted in general.
Passive buzzer did not drive the internal circuitry, some companies and factories called Xiangqi hearing, known as the national standard of sound device. Passive work buzzer ideal square wave signal. If the signal to the pre-DC is not in response to the buzzer, as a constant magnetic circuit, molybdenum film vibration can not pronounce.
Six or passive electromagnetic and piezoelectric buzzer buzzer how passive and electronic circuits in the IC output pin connector?
Passive belonging to the buzz of electromagnetic inductive load devices are ideal input square wave is usually recorded as: VO-P. Usually circuit wiring are as follows:
Passive pressure capacitive load devices belonging to the buzz, the ideal is two-way input square wave is usually recorded as: VP-P. Usually circuit wiring are as follows:
However, if the reverse is the IC-4049, and so on, taking a non-door buzzer access input and output is also ideal, but sometimes the IC output is too small, the sound did not achieve the requirements.
If the buzzer is loud as the pressure to use the report to the police, ordinary pin inductance of the two can not meet the requirements of the General Council adopted three-tap inductors, usually 10 times more than the step-up, some shouting pressure will have to use more than 110dB Low-power to achieve step-up transformer.