音频放大器的设计与制作

音频放大器的设计与制作

摘要

伴随着科学技术的迅速发展，人们生活水平的不断提高，对音频功率放大器的要求越来越高。音频是多媒体中的一种重要媒体。人能够听见的音频信号的频率范围大约是 60Hz-20kHz 其中语音大约分布在300Hz-4kHz之内，而音乐和其他自然声响是全范围分布的。

如何通过分析仪器让音频功放达到更高的要求是许多人为之努力的永恒的课题，声音经过模拟设备记录或再生，成为模拟音频，再经数字化成数字音频，音频分析就是以数字音频信号为分析对象以数字信号处理的各种理论为分析手段，提取信号在时域，频域内一系列特性的过程。

音响技术的发展历史可以分为电子管、晶体管、集成电路、场效应管四个阶段。

1906年美国的德福雷斯特发明了真空三极管，开创了人类电声技术的先河。1947年威廉逊先生在一篇设计Hi-Fi（High Fidelity）放大器的文章中介绍了一种成功运用负反馈技术，成为了Hi-Fi史上一个重要的里程碑。

60年代由于晶体管的出现，使功率放大器步入了一个更为广阔的天地。晶体管放大器细腻动人的音色、较低的失真、较宽的频响及动态范围等特点，各种电路也相应产生。直至70年代，晶体管放大技术的应用已相当成熟，各种新型电路不断出现，如：较成功地解决了负反馈电路的瞬态失真和高频相位反转问题的无负反馈放大电路；成功地将甲、乙放大器的优点结合在一起的超甲类放大电路；具有输出功率大、失真小的电流倾注式放大电路等等。从而使晶体管音频放大器成为音响技术发展中的主流。

关键词：音频功率放大器反馈音响集成电路

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Abstract

38 An all-around audio test and analysis needs all kinds of expensive special instruments, for instance the signal generator, spectral analysis instrument, which should be well organized. Obviously, it is certain difficulty for laboratory of the college in this; unfavorable to users and test functions on the basis of one's own need too. In addition, the data can't be store in traditional instrument; it is not apt to find the instantaneous change of the signal.

With the constant development of modern electronic technology, the microprocessor and personal computer, the rise of the fictitious instrument has provided the new way for the researching and analyzing of amplifier performance of the power.

Based on studying the fundamental theory of audio analysis, this paper puts emphasis on how to import virtual instrument technology into designing audio analyzer, and creates fire-new virtual audio analyzer.

The result of the test in the experimentation shows that, the system has realized the amplifier signal frequency of the power, peak-to-peak, enlarge coefficient, harmony wave, spectrum analyzer, rise time, rise rate, fall time, falling rate, and the width of frequency. Utilize the fictitious instrument in the test analyzing to the circuit, then improve the circuit, test after improving , is improving the performance of the whole circuit constantly , thus respond to the request that the circuit is designed.

Key words：Audio Amplifier,Virtual Instrument ,Test and Analyze,LabVIEW

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