The microphone is one of the important components of the telephone. It can convert the sound into voice current
The microphone is one of the important components of the telephone. It can convert the sound into voice current, so it is a sound-electric conversion device. Microphones are generally divided into two categories, namely linear microphones and non-linear microphones. People call the microphone whose sensitivity does not change with the sound pressure as a linear microphone, and vice versa, it is called a non-linear microphone. Among the commonly used microphones, carbon microphones are nonlinear microphones, and electromagnetic microphones, moving coil microphones, piezoelectric microphones, and electret microphones are linear microphones. device.
Microphones are divided into positive and negative poles. Attention should be paid during maintenance. If the polarity is reversed, the microphone will not be able to output signals. In addition, the microphone also needs to provide a bias voltage when it is working, otherwise, the failure phenomenon that the microphone cannot be sent will also occur.
The connection between the microphone and the main board is one-touch and soldering.
Touch-type mobile phones do not transmit due to poor contact, you can clean the contacts first, and tighten the shell screws; for welding-type mobile phones, the microphone is welded on the motherboard, and there will be no poor contact. , The failure to send calls is mostly caused by the dust entering the microphone blocking the microphone hole or the microphone itself being damaged. Of course, it does not rule out that the audio circuit is damaged.
The microphone is divided into positive and negative poles. If the polarity is reversed, the microphone cannot output signals. The way to judge whether the microphone is damaged is: put the digital multimeter in the R×1Ω gear, the red test pen picks up the positive pole of the microphone, the black test pen picks up the negative pole of the microphone (the opposite is the case for the pointer type multimeter), and speak to the microphone , if the microphone is good, the multimeter reading will change or the pointer will wobble