自激式与他激式蜂鸣器区别
依照驱动信号的不同,蜂鸣器分为自激式及他激式二类,有很多不同说法,但指的都是这二种分类,
如:内含(不含)线路,直流DC/交流AC Type, 有源(无源),
自激式蜂鸣器是将驱动线路直接设计到蜂鸣器中,故只需给予直流电压,
内含的驱动线路,就会产生设计好的频率及电压给蜂鸣器发声,所以自激式的频率是固定的。
但每颗蜂鸣器间的频率仍会有些差异,一般常见的是2300Hz, 频率上下300Hz都算可接受的范围,
而他激蜂鸣器,需由外部线路给予1/2方波V 0-p(电磁式),或方波Vp-p(压电式)的信号,才会发声,
在使用上用自激式的蜂鸣器有其方便的地方,但因为成本及不良率较高,且频率不可调整,
| 售 价 | 不良率 | 频率调整 | 方 便 性 | |
| 自激式蜂鸣器 | 较高 | 较高 | 不可调 | 加电压即可 |
| 他激式蜂鸣器 | 较低 | 较低 | 可调整 | 需振荡线路 |
The difference between the self drive and external drive buzzers
The difference between the self drive and external drive buzzers
Depend on the driving signal, the buzzer divide into self drive and external drive. However inner circuit/ no circuit, DC/ AC, and active/ passive are all mean the same.
The design of the self drive buzzer is to set the circuit inside the buzzer and just offer the direct current to work. The inner circuit has the designed frequency and voltage for the buzzer to generate sound, therefore the frequency of the self drive buzzer is fixed. However the frequency is still different from each buzzer, normally is 2300Hz, the acceptable range is +/-300Hz.
However, the external drive buzzer needs to be drove by the signal of 1/2 square wave V 0-p (magnetic type), or square wave V p-p (piezo buzzer)
It is convenient to use a self drive buzzer, but the disadvantages are the higher cost, the higher defective rate and the unchangeable frequency.
The comparison between self and external drive buzzer:
| Cost | Defective rate | Frequency | Convenience | |
| Self drive buzzer | High | High | Unchangeable | Need only voltage |
| External drive buzzer | Low | Low | Changeable | plus oscillate circuit |
