Teaching wireless microphone product classification
According to the principle of sound-electric conversion: electric type (moving coil type, aluminum ribbon type), capacitive type (DC polarization type), piezoelectric type (crystal type, ceramic type), electromagnetic type, carbon particle type, semiconductor type Wait.
According to the force of the sound field, it is divided into: pressure type, pressure difference type, combined type, linear type and so on.
According to the transmission method of electric signal, it is divided into wired and wireless.
Divided by purpose: measuring microphone, vocal microphone, instrument microphone, recording microphone, etc.
According to the directivity, it is divided into: cardioid, sharp-hearted, super-cardioid, bidirectional (8-shaped), non-directional (omnidirectional).
Electret microphones are small in size and low in cost, and are widely used in telephones, mobile phones and other equipment.
Features of teaching wireless microphone:
1. Most microphones are electret condenser microphones (ECM). This technology has been around for decades. ECM works by vibrating the membrane of a polymer material that is isolated from the permanent charge.
2. Compared with the polymer diaphragm made by ECM, the microphone performance under different temperatures is stable, and it is not affected by temperature, vibration, humidity and time. Due to its high heat resistance, the microphone can be reflow soldered at a high temperature of 260 degrees without changing its performance. Since the sensitivity to changes before and after assembly is not high, this can even save the cost of audio debugging during the manufacturing process.
3. The microphone needs ASIC to provide external bias, while ECM does not need this bias. The effective bias allows stable acoustic and electrical parameters throughout the operating temperature range. The external bias of the chip also supports the design of microphones with different sensitivities.
4. The size of traditional ECM is usually larger than that of microphone, so it cannot perform SMT operation. SMT reflow simplifies the manufacturing process, and the manufacturing steps can be omitted.
5. There is no difference between integrated circuits and electret condenser microphones in signal processing of electronic components, but this is a technology that has been used. In the electret, you must add an integrated circuit, and in the microphone, you only need to add additional specialized functions on the integrated circuit. Compared with ECM, the advantage of this additional function is that the microphone has a high power rejection ratio. In other words, if the power supply voltage fluctuates, it will be effectively suppressed.
Classification of teaching wireless microphone functions:
1. The performance of the microphone mainly uses dynamic microphones and condenser microphones (mainly selected according to the use occasions and requirements).
2. Recording microphones mainly use condenser microphones and ribbon microphones. Recording condenser microphones do not contain electret microphones.
3. Conference microphones mainly use electrets and a small amount of dynamic microphones.