Views:106 Author:Site Editor Publish Time: 2019-11-25 Origin:Site
The working principle of the IC magnetic buzzer is that the chip oscillates a square wave signal with a fixed frequency to drive the buzzer. There is only one set of coils in the buzzer, buzzer does not need feedback coil to participate in oscillation. The peripheral components are very simple (only the high voltage version has the resistor R *), and the reliability and stability are improved.
Disadvantages of traditional magnetic active buzzer
1.The frequency changes with the change of the driving voltage. When the voltage increases, the frequency will decrease; when the voltage decreases, the frequency will increase. The change may be 200Hz to 300Hz, so the human ear can clearly distinguish the tone change.
2.The frequency changes with the change of temperature, when the temperature increases, the frequency will decrease; when the temperature decreases, the frequency will increase. The change will probably be 50Hz to 100Hz.
3.Peripheral circuits have an effect on the buzzer
1）In order to obtain the required voltage, the customer will connect a voltage dividing resistor in series in the driving circuit. As the resistance value increases, it will affect the internal oscillation of the buzzer, which will seriously cause the oscillation to stop and become silent.
2）In order to reduce the sound pressure of the buzzer, the customer will connect a voltage dividing resistor in series in the driving circuit. As the resistance value increases, it will affect the internal oscillation of the buzzer, which will seriously cause the oscillation to stop and become silent.
3）In order to make the buzzer has intermittent tone, the customer sets the control circuit. The control circuit has complex components that will cause the buzzer to work abnormally.
Advantages of IC magnetic buzzer over traditional models
1.Because the IC has low voltage compensation and high voltage stability, the voltage increase and decrease will not affect the frequency change.
2.The chip has a temperature compensation function, the temperature change has almost no effect on the buzzer frequency, and the ear cannot hear the tone change.
3.The peripheral circuit has a great impact on the traditional active buzzer (analyzed in detail above). One obvious reason is that the customer's circuit will affect the oscillation circuit inside the buzzer. All improvements are made so as not to affect the oscillation circuit inside the buzzer. IC has a unique advantage in this regard, because its own oscillation does not rely on coil feedback oscillation, compared to peripheral circuits has little effect.