Vehicle-mounted audio frequency circuit

Abstract

The invention provides a vehicle-mounted audio frequency circuit, which comprises an audio frequency signal processor, an active amplifying filter circuit, a long wire harness, a passive attenuation filter circuit and an external amplifier; the active amplifying filter circuit and the a passive attenuation filter circuit are arranged between the audio frequency signal processor and the external amplifier; sound source signals are amplified by the active amplifying filter circuit and transmitted by the long wire harness, so the amplified sound source signals can effectively resist various interferences on the long wire harness; on the other hand, the sound source signals on the long wire harness are attenuated by the passive attenuation filter circuit for matching the amplitude scope of the input signals supported by the external amplifier; and the interference noise on the long wire harness is filtered at the same time. The vehicle-mounted audio frequency circuit can effectively restrain noise interference on the long wire harness and obviously improve the signal to noise ratio of the vehicle-mounted sound system. In addition, the circuit is simple in structure and low in cost, which is suitable for low-end and old cars.

Description

technical field [0001] The invention relates to the technical field of automotive electronics, in particular to a vehicle audio circuit. Background technique [0002] At present, the audio source of the car main unit is transmitted to the external power amplifier through a long wire harness in the form of analog signal transmission. However, with the increase of electrical components in automobiles, there are more and more mutual interference phenomena between electrical components. The most obvious interference is the signal conduction interference of the signal line, so the audio source signal is transmitted to the external power amplifier, which introduces interference noise, and the signal-to-noise ratio is significantly reduced. Due to the large noise floor of the external power amplifier, the sound quality is greatly affected. . [0003] see figure 1 , which is a schematic diagram of a vehicle audio circuit in the prior art. [0004] Both the output port of the aud...

AI Technical Summary

Problems solved by technology

But there are the following disadvantages at the same time: using digital signals for transmission, the circuit must increase the A / D encoder (set at the front end of the audio signal processor), D / A decoder, and network transmitter and network receiver, which greatly improves the cost, and the technical requirements are relatively high, and the development cycle is relatively long

For low-end models and old models, analog signal transmission is used. In view of the cost and compatibility of old products, this digital signal transmission circuit is not suitable for popular application between the host and external power amplifier.

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