2007年12月2日 星期日

How to choose a buzzer 如何選用蜂鳴器

How to choose a buzzer

There are many different kinds of buzzer to choose, first we need to know a few parameters, such as voltage, current, drive method, dimension, mounting type, and the most important thing is how much SPL and frequency we want.Operating voltage: Normally, the operating voltage for a magnetic buzzer is from 1.5V to 24V, for a piezo buzzer is from 3V to 220V. However, in order to get enough SPL, we suggest giving at least 9V to drive a piezo buzzer.Consumption current: According to the different voltage, the consumption current of a magnetic buzzer is from dozens to hundreds of mill amperes; oppositely, the piezo type saves much more electricity, only needs a few mill amperes, and consumes three times current when the buzzer start to work.Driving method: Both magnetic and piezo buzzer have self drive type to choose. Because of the internal set drive circuit, the self drive buzzer can emit sound as long as connecting with the direct current. Due to the different work principle, the magnetic buzzer need to be driven by 1/2 square waves, and the piezo buzzer need square waves to get better sound output.Dimension: The dimension of the buzzer affects its SPL and the frequency, the dimension of the magnetic buzzer is from 7 mm to 25 mm; the piezo buzzer is from 12 mm to 50 mm, or even bigger.Connecting way: Dip type, Wire type, SMD type, and screwed type for big piezo buzzer are usually seen.SPL: Buzzer is usually tested the SPL at the distance of 10 cm, if distance double, the SPL will decay about 6 dB; oppositely, the SPL will increase 6 dB when the distance is shortened by one time. The SPL of the magnetic buzzer can reach to around 85 dB/ 10 cm; the piezo buzzer can be designed to emit very loud sound, for example, the common siren, are mostly made of piezo buzzer.
Introduction of magnetic buzzer - Introduction of piezo buzzer
如何選用蜂鳴器
蜂鳴器的種類規格繁多,需先知道幾個參數 ( 電壓,電流,驅動方式,尺寸,連接/固定方式),當然更重要的是,想要獲的聲音 (音壓大小,頻率高低),
工作電壓: 電磁式的蜂鳴器, 從1.5到24V, 壓電式的從3V到220V都是可行的,但一般壓電的還是建議有9V以上的電壓,以獲得較大的聲音.
消耗電流: 電磁式的依電壓的不同,從幾十到上百毫安培都有,壓電式的就省電的多,幾毫安培就可以正常的動作, 且在蜂鳴器啟動時,瞬間需消耗約三倍的電流,
驅動方式: 二種蜂鳴器都有自激式的,只要接上直流電(DC)即可發聲,因為已內建了驅動線路在蜂鳴器中了,因為動作原理的不同,電磁式蜂鳴器要用1/2方波來驅動,壓電的用方波,才能有較好的聲音輸出.
尺寸: 蜂鳴器的尺寸會影響到音量的大小,頻率的高低,電磁式的最小從7mm到最大的25mm,壓電式的從12mm到50mm或更大都有.
連接方式: 一般常見的有插針(DIP), 焊線(Wire), 貼片(SMD), 壓電式大顆的還有鎖螺絲的方式.
音壓: 蜂鳴器常以10cm的距離做為測試的標準,距離增加一倍,大概會衰減6dB, 反之距離縮短一倍則會增加6dB,電磁式蜂鳴器大約能達到85dB / 10cm的水準,壓電式的就可以做的很大聲,常見的警報器,大都是以壓電蜂鳴器製成.
以苙翔的料號, 用量最大的電磁式蜂鳴器AC-1205G為例
A = AATC
C = 一體式,底部有封環氧樹脂的蜂鳴器, 另有AS = 分體式,底部沒封膠,一般頻率為2000左右,不可過錫爐. AX表內含驅動線路(自激式).AD表SMD的.
12 = 直徑,單位是mm, 還有6.7, 9.0, 9.6, 14, 16, 25mm的,並有多種高度選擇
05 = 額定工作電壓, 還有1.5, 3.0, 3.5, 5, 6, 9, 12, 24V.
G = 直流阻抗
壓電式的以AZ-1440S-P為例
A = AATC 苙翔科技
Z = Piezo 壓電式蜂鳴器
14 = 直徑, 10, 12, 14, 16, 17,.....50規格非常多.
40 = 額定的頻率, 40表4KHz,
S = Self drive 自激式,內含線路的, E 表他激, 外部驅動.
P = Pin type, 還有W- Wire, APD-SMD的

3 則留言:

yo 提到...

你好,
我想知道怎麼傳輸麥克風的訊號到電腦??...
謝謝

Michael 提到...

電腦指的是PC嗎?
一般PC, NB都有3.5mm的麥克風插孔吧.

CresceNet 提到...

Gostei muito desse post e seu blog é muito interessante, vou passar por aqui sempre =) Depois dá uma passada lá no meu site, que é sobre o CresceNet, espero que goste. O endereço dele é http://www.provedorcrescenet.com . Um abraço.