A Compatible Car Microphone Circuit

Abstract

A compatible vehicle-mounted microphone circuit, comprising a socket, a detection circuit, a first input matching circuit, a second input matching circuit, a first switching circuit, a second switching circuit and a CPU; the detection circuit input is connected to the socket to detect the state of the socket ; The first switching circuit is connected to the second switching circuit to control the opening or closing of the matching of the input circuit; the second switching circuit is connected to the first input matching circuit and the second input matching circuit to control access to the first input matching circuit or the second input matching circuit Two input matching circuits; the CPU is connected to the output terminal of the detection circuit, the first switching circuit, the second switching circuit and the socket to control whether to collect the socket voltage value according to the state of the socket, and compare the voltage value with a pre-stored threshold value to determine the microphone type and Controlling the actions of the first switching circuit and the second switching circuit realizes the matching of the input circuit. The invention can realize the compatible use of the dynamic microphone and the condenser microphone, and has simple circuit and low cost.

Description

technical field [0001] The invention relates to the field of microphone circuits, in particular to a compatible vehicle-mounted microphone circuit. Background technique [0002] In the application of vehicle-mounted multimedia terminal equipment in passenger cars, especially tourist buses, it is generally required that the multimedia terminal equipment needs to have a microphone for calling out. As people diversify their entertainment functions, some customers need to be equipped with dynamic wired microphones. Some customers require a capacitive wired microphone, and the principles of the two microphones are different, so the compatibility of the two microphone input circuits needs to be considered during the circuit design process. [0003] The dynamic microphone uses the principle of electromagnetic induction to convert the sound signal into an electrical signal by cutting the magnetic induction line through the coil in the magnetic field. The condenser microphone, also ...

AI Technical Summary

Problems solved by technology

The condenser microphone, also called an electret microphone, its core component is the stage head, which is composed of two metal films; when the sound wave causes it to vibrate, the difference in the distance between the metal films causes the difference in capacitance, thereby generating a current. It uses the change of capacitance to convert the sound signal into an electrical signal. It must be driven by an independent power supply, generally 1.5V. If the two microphones are input on the same interface, and the input circuit is not compatible design, it will cause inconvenience in actual use, or cause a problem that the microphone cannot be used normally

[0004] In addition, when these two microphones are actually used, there is often a "pop" sound when the microphone is turned on. For this kind of switching noise, if it is not dealt with, it will often bring a harsh sound to passengers.

In view of these problems, a circuit and method compatible with vehicle-mounted dynamic microphones and condenser microphones are needed to solve the compatibility problems of these two microphones in actual use and to optimize the noise problem.

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