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驻极体传声器与电路的接法为您详细说明介绍

  驻极体话筒与电路的接法有两种:源极输出与漏极输出。源极输出类似晶体三极管的射极输出。需用三根引出线。漏极D接电源正极。源极S与地之间接一电阻Rs来提供源极电压,信号由源极经电容C输出。编织线接地起屏蔽作用。源极输出的输出阻抗小于2k,电路比较稳定,动态范围大。但输出信号比漏极输出小。漏极输出类似晶体三极管的共发射极放入。只需两根引出线。漏极D与电源正极间接一漏极电阻RD,信号由漏极D经电容C输出。源极S与编织线一起接地。漏极输出有电压增益,因而话筒灵敏度比源极输出时要高,但电路动态范围略小。
  Rs和RD的大小要根据电源电压大小来决定。一般可在2.2~5.1k间选用。例如电源电压为6V时,Rs为4.7k,RD为2。2k。图3输出电路中,若电源为正极接地时,只须将D、S对换一下,仍可成为源、漏极输出。一声控电路前置放大级中驻极体话筒的源极输出和漏极输出的两种不同的接法,最后要说明一点,不管是源极输出或漏极输出,驻极体话筒必须提供直流电压才能工作,因为它内部装有场效应管

Electret microphones and circuits are connected in two ways: source output and drain output. The source output is analogous to the emitter output of the transistor. Three lead wires are needed. Drain is connected to the positive terminal of the power supply. A resistor Rs is provided between the source S and the ground to provide a source voltage. The signal is output from the source through the capacitor C. The braided wire ground serves as a shield. The output impedance of the source output is less than 2k, the circuit is relatively stable, and the dynamic range is large. However, the output signal is smaller than the drain output. The drain emitter outputs a common emitter like a transistor. Only two leads are required. The drain D and the positive electrode of the power supply indirectly have a drain resistance RD. The signal is output from the drain D via the capacitor C. The source S is grounded together with the braided wire. The drain output has a voltage gain, so the microphone sensitivity is higher than the source output, but the circuit dynamic range is slightly smaller.
The size of Rs and RD depends on the power supply voltage. Generally can choose between 2.2~5.1k. For example, when the power supply voltage is 6V, Rs is 4.7k and RD is 2. 2k. In the output circuit of Fig. 3, if the power supply is positively grounded, it is only necessary to replace D and S, and it can still be a source and a drain output. A voice circuit pre-amplifier stage electret microphone source output and drain output of the two different connections, and finally to point out that no matter the source output or drain output, electret microphone must provide DC The voltage can work because it has a FET inside it
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