摘 要
随着人们生活水平的进一步提高，高保真音响设备和家庭影院系统已经逐步进入了人们的家庭，人们对娱乐消费类电子产品的需求欲望亦日渐高涨，建立适合自己口味的高保真梦幻组合和家庭影院也已经不再是梦想。
本论文将以性价比为导向，兼顾基本的高保真的技术指标，讨论了适合一般家用的多媒体高保真功放。论文由浅至深，结合图示介绍了家用音响的组成和相关知识，以及整个功放的工作过程的细节，内容涉及输入前置放大电路、音调控制和音色处理电路、功率放大电路、电源电路。同时还对各个主要芯片自身的特点及如何去设计这个系统来满足一定的技术指标进行了讲解。论文尽可能通俗地来介绍家用音响，让大家能从中学到基本的家用组合音响的知识的同时，还能学会如何制作高保真音频放大器以及对音响器材选购作出正确的选择。
在技术层面上，系统主要是采用集成芯片来完成的，这个设计中用NS（National Semiconductor）公司带有3D环绕声场处理功能的LM4610N做音调芯片，通过改变直流控制电压来实现音调控制；前置放大使用了曾经的“运放之皇”NE5532，典型的增益为20dB；后级功率放大部分用的也是NS公司的一款经典芯片――LM1875芯片，每声道两片，驳接成桥式推挽BTL电路,以取得更大的功率以及更好的音效；此外此音响还带有无信号或定时智能关机的电源控制设计，以适应一般家用的使用习惯。
在论文的后面部分，着重讲述了制作和调试中遇到的软件、硬件上的问题以及如何解决，并给出了音频功率放大器性能指标的国家标准测量方法。这些可以成为大家制作过程中的一些的提示以及测试的依据。
关键词：3D环绕；集成芯片；直流电压音调控制；BTL；无信号自动关机
Abstract
With the development of people’s living standards, the hi-fi audio system and family video system have come into people’s life. It’s no longer a dream to establish a suitable and favorable hi-fi audio system as people’s desires for electronic products are becoming stronger.
Under the guidance of the ratio between quality and price, considering the basic technical index, the essay discusses the ordinary multi- media hi-fi audio amplifiers. The content of the essay develops from shallow to profound, and is illustrated with diagrams to introduce the structures and relative knowledge of the household audio system, and also the detailed working procedures, including the entry of front extending circus, volume controller, voice dealing circus, efficiency extending circus and supply circus. And meanwhile the essay describes the features of the main chip and also on how to use and to learn from this system.
I’ve tried my best to make the language of this essay easy and simple for readers, and with every wish that they can learn something useful from my works: how to make an audio system, and how to choose the right materials for it.
As per techniques, the design chiefly adopts the integrated chips. In this design, I adopted the NS’s LM4610N with 3D voice encircling function as the leading chips, by changing the voltage of direct circus to control the volume. The front amplifier is the “Master of amplifier” NE5532, with the typical increase 20dB. The rear efficiency amplifier also adopts NS’s LM1875, every step two pieces, bridging into BTL push-pull circus so as to achieve the higher efficiency and better voice. Besides, for customers’ convenience, the system can timely be turned of f automatically when there is no signal.
At the end of my essay, I also state about the difficulties and problems during my design and test, the ways to solves these problems and also offer some standard national testing approaches for reader’s references.
Key words: 3D encircling; Integrated chips; Voltage controller of direct current; BTL;
Automatically turned off without signal;
目 录
