How a Telephone Microphone Works

The following is the circuit diagram of FM wireless microphone. The high-frequency transistor V1 and the capacitors C3, C5 and C6 form a three-point capacitor oscillator. For beginners, we don't need to think about the specific working principle of the capacitor three-point oscillator for now. You should know that this circuit structure is a high-frequency oscillator. The charge C4 and L of the triode collector form a resonator. The resonant frequency is the transmitting frequency of the FM microphone. According to the component parameters in the figure, the transmitting frequency can be between 88 and 108 MHz, which just covers the. FM radio reception frequency. By adjusting the L digital value (stretching or compressing the L coil) can easily change the broadcast frequency and avoid FM radio stations. The transmitted signal is coupled to the antenna via C4 and then transmitted.

R4 is the resistancee base bias of V1, which provides a certain base current to the transistor so that V1 operates in the amplification region. R5 is the DC feedback resistor, which stabilizes the operating point of the transistor.

The frequency modulation principle of this FM microphone is to achieve frequency modulation by changing the capacitance between the base and the triode transmitter when the sound voltage signal is added to the base of the triode, the base of. the triode and the capacitance between the transmitters will change synchronously with the size of the sound voltage signal, and at the same time, the emission frequency of the triode will change, realizing frequency modulation.

What is the principle of a dynamic microphone?

First of all, it doesn't matter whether you use a dynamic condenser microphone or an electret microphone. Let me summarize it: Determining the clarity of your recording depends primarily on the sensitivitybility. The higher the sensitivity, the easier it is to record details. The second frequency response refers to the sensitivity performance at a certain frequency. The wider the frequency response, the more frequency content can be recorded. , the more realistic the recording is. , the most compelling example of impedance is a dynamic microphone which is equivalent to a small generator and has a certain power load when the impedance is matched, the maximum output power can be obtained. the input impedance is large, the power consumption of the microphone is small, but the drive current is small, which affects the quality of amplification. If the input impedance is too small, the current that the microphone must provide is very large. If it exceeds the current that the microphone can deliver within the normal range, distortion will occur. I don't know if the answer is complete, please continue to askander if you have any questions

The electromagnetic phenomenon. Induction is widely used in production, life and scientific research. Please list the devices that use the principle of electromagnetic induction: ①______

Question 1: The working principle of dynamic microphone is realized by using the phenomenon. electromagnetic response.

When sound waves vibrate the metal diaphragm, the coil (called the voice coil) connected to the diaphragm vibrates together, and the voice coil vibrates in the magnetic field of the magnet permanent. An induced current (electrical signal) is generated. The magnitude and direction of the induced current change is determined by the sound waves. This signal current is amplified by the amplifier and then transmitted to the speaker. an amplified sound is output from the speaker.

Question 2: The principles of dynamic microphones and earpiecess they are different? The microphone changes current and generates a magnetic field. The earphone changes magnetic field and generates an electric field. the microphone, the sound vibrates the diaphragm and the magnetic material of the earpiece changes in unequal magnetic fields to generate current

Question 3: The principle of coil microphone mobile. Microphone (moving coil microphone, engineering acoustics moving coil microphone, moving coil microphone) is to transform sound into a device for electrical signals. Dynamic microphones are manufactured using the phenomenon of electromagnetic induction. When sound waves vibrate a metal diaphragm, a coil (called a voice coil) connected to the diaphragm vibrates together, and the voice coil vibrates in the magnetic field of a permanent magnet. An induced current (electrical signal) is generated. The magnitude and direction of the undue current changeit are determined by the sound wave. This signal current is amplified by the amplifier and then transmitted to the speaker. amplified sound is output from the speaker.

Question 4: The working principle of the dynamic microphone in the picture is the same (Analysis C: Since the working principle of the dynamic microphone is electromagnetic induction, only energy production in C The principle of the machine is the same, so choose C

Question 5: What are the principles of dynamic microphones and speakers of generators and motors

Question 6: The working principle of dynamic microphones is the same as that of electrical devices The structure of dynamic microphones is the same as that of dynamic headphones. The working principle is reverse! The sound waves push the diaphragm! The coil on the diaphragm core vibrates in the strong magnetic gap!! The latter is the coil generating an alternating magnetic field through the audio current. It interacts with the permanent magnet to make the vibrating membrane emit sound waves! ! table> The phenomenon of electromagnetic induction has many applications in life. The principle used by instruments that generate induced current by cutting magnetic induction lines through wires is the principle of electromagnetic induction;

In daily life there are many examples: such as generators, microphones, transformers, etc. ;

So the answer is: generator; microphone;