Take omnidirectional MIC, diaphragm type pole ring connection type as an example
1. Dust net:
Protect the microphone to prevent dust from falling on the diaphragm, prevent external objects from piercing the diaphragm, and have a short-term waterproof effect.
The whole support part of the microphone, other parts are encapsulated in the shell, is the grounding point of the microphone, and can also play the role of electromagnetic shielding.
3. Diaphragm: It is a main part of sound-electric conversion, it is a tight Teflon plastic film glued to a thin metal ring, and the side of the film contacting the metal ring is plated with a very thin metal layer. The film can be charged with electric charge, it is also an electrode plate that forms a variable capacitor, and it is an electrode plate that can vibrate.
The distance between the two plates of the supporting capacitor is left with a gap to provide a space for the vibration of the diaphragm, thereby changing the capacitance.
5. Back plate:
The other electrode of the capacitor is connected to the G (gate) electrode of the FET (Field Effect Transistor).
6. Copper ring:
Connect the pole plate to the G (gate) pole of the FET (field effect tube) and play a supporting role.
Fix the pole plate and pole ring to prevent the pole plate and pole ring from being short-circuited to the case (the S (source) and G (gate) poles of FET (field effect tube) are short-circuited).
8. PCB components:
Equipped with FETs, capacitors and other devices, it also plays a role in fixing other parts.
9. PIN: Some microphones have a PIN (pin) on the PCB, which can be welded with other PCBs through PIN, and the front pole type and back pole type are also slightly different in structure.
1. From the working principle: carbon granular type, electromagnetic type, capacitive type, electret capacitive type (the following introduction is mainly electret type), piezoelectric crystal type, piezoelectric ceramic type, silica type, etc.
2.From the size, the electret can be divided into several types.
Φ9.7 series products Φ8 series products Φ6 series products
Φ4.5 series products Φ4 series products Φ3 series products
There are different heights in each series
3. From the directionality of the microphone, it can be divided into omnidirectional, one-way, and two-way (also known as noise reduction type)
4. Divided from the polarization mode, diaphragm type, back pole type, front pole type
From the structure, it can be divided into grid spot welding type, grid crimping type, pole ring connection type, etc.
5. From the external connection method
Common solder joint type: L type
With PIN foot type: P type
Concentric circle type: S type