Views:45 Author:Site Editor Publish Time: 2021-01-29 Origin:Site
A piezo buzzer is an audio signalling device that uses piezoelectric ceramics as an electro-acoustic transducer. The core of this device is a transducer made of a piezoelectric ceramic sheet pasted onto a metal sheet, that is, a piezoelectric buzzer element. The characteristics of piezoelectric buzzer, i.e. without radio frequency noise and low power consumption, make it highly valued and developing very rapidly. An "active" buzzer generates the sound itself, while with a "passive" device or speaker, you need AC "sound signal" to control the sound.
So Let’s talk about the technology that can make passive piezo buzzers wide-spread.
·What are the advantages of the passive piezo buzzers?
·What technology does the passive piezo buzzer use?
·How can you choose a passive piezo buzzer correctly?
1. Since there are no moving contact parts, passive piezo buzzer has a long service life and high reliability, together with the continuous use time is up to 10,000 hours, which belongs to a semi-permanent device.
2. Passive piezo buzzer does not produce arc or radio frequency system noise, as well as no interference to other related lines.
3. Passive piezo buzzer will not cause big vibration due to looseness.
4. Using electronic circuit control, passive piezo buzzer can emit a variety of pleasant sounds, analog sounds and intermittent sounds.
5. Passive piezo buzzer has higher SPL but smaller size. Passive piezo buzzer has wide operating temperature range.
6. The passive piezoelectric buzzer can be easily installed without electromagnetic coils or moving coils. There is no need to worry about insulation deterioration or leakage.
Passive piezo buzzer does not produce arc and noise so that it has many advantages in performance and adaptability, which is the first choice for everyone. Passive piezo buzzers generally use two types supporting methods to use.
The first type is node support method. It is to fix the buzzer piece of the passive piezo buzzer in a ring structure approximately the same size as the diameter of the ceramic piece. If the resonant cavity is properly designed, being matched with the correct frequency of the feedback buzzer and the positive feedback circuit, then the correct frequency and greater sound pressure can be generated.
The second type is peripheral support method. It is to fix the edge of the outer diameter of the buzzer of the passive piezo buzzer in the resonant cavity. This method is generally a non-feedback buzzer, and it must be matched with the frequency of the resonant cavity to have a relatively high sound pressure output. An external oscillator circuit must generate a driving signal to make the buzzer sound.
Passive piezo buzzer is widely used for alarm and sounding purposes of various electrical products, such as music greeting cards, electronic watches, pocket calculators, household appliances and etc. In order to ensure the quality of passive piezo buzzer we choose, we should strictly check and select the most suitable products when purchasing.
The first method is to choose according to the voltage. The passive piezo buzzer is generally driven by a square wave (V P-P). The second method is to choose according to the size. Choosing the passive piezo buzzer according to the size is mainly based on the principle that the size will affect the frequency. Generally, the frequency of small size is higher.
The third method is to choose according to the pin pitch. There are many specifications of passive piezoelectric buzzers, and it is often difficult to find exactly the same specifications. In this case, we can pick the pitch and try the frequency close.
The last but not least method is to choose according to drive development mode. If we cannot provide frequency signals to the passive piezo buzzer, we can fully consider the use of embedded drive circuits, realizing to provide DC voltage.
Learning something about passive piezo buzzer can help you know the advantages of the passive piezo buzzers and make right choice of the passive piezo buzzers. If you want to buy high-quality piezo buzzers with reasonable price, Kailitech Company can provide you with the best products. We also have other piezo buzzers and piezo transducers, having an independent factory and a complete production line.