2020-12-14
Condenser microphone is a kind of microphone to convert the sound signal into electrical signal by the change of capacitance size. This kind of microphone is the most common one. The built-in microphone of recorder is of this kind, because it is cheap, compact, and the effect is not bad. Sometimes it is also called “mic head”.
The condenser microphone has two metal plates, one of which is coated with electret film (most of which is perfluoroethylene propylene) and grounded. The other plate is connected to the gate of field-effect transistor, and a diode is connected between the gate and the source. When the electret diaphragm itself has a charge, the surface charge is Q, and the capacitance between the plates is C, the voltage generated on the electrode head is U= Q/C. When the electret diaphragm is subjected to vibration or air friction, the distance between the two plates is changed due to vibration, that is, the capacitance C changes, while the electric quantity Q remains unchanged, which will cause the voltage change. The magnitude of the voltage change reflects the strength of the external sound pressure. The frequency of the voltage change reflects the frequency of the external sound, which is the working principle of the electret microphone.
The advantages of condenser microphones:
Condenser microphone is based on the principle of capacitance charge and discharge between conductors. It uses ultra-thin metal or gold-plated plastic film as diaphragms to induce sound pressure, so as to change the static voltage between conductors and directly convert it into electrical energy signal. Practical output impedance and sensitivity can be obtained by coupling electronic circuits.
The disadvantages of condenser microphones:
The structure is complicated, the cost is expensive, the sound film is fragile and afraid of moisture, and it is difficult to promote.
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Guangdong Huaze Acoustics Technology Co., Ltd. , established in Dec 2019, located in Dongguan, is a high-tech enterprise which aims at developing and producing auto acoustics products.