低频功率放大器毕业设计论文

低频功率放大器

毕业设计论文

【摘要】实用低频功率放大器主要应用是对音频信号进行功率放大，本文介绍了具有弱信号放大能力的低频功率放大器的基本原理、内容、技术路线。整个电路主要由稳压电源、前置放大器、功率放大器、波形变换电路和保护电路共五部分构成。稳压电源主要是为前置放大器、功率放大器提供稳定的直流电源。前置放大器主要是电压的放大。功率放大器实现电流、电压的放大。波形变换电路是将正弦信号电压变换成规定要求的方波信号。设计的电路结构简洁、实用，充分利用到了集成功放的优良性能。实验结果表明该功率放大器在带宽、失真度、效率等方面具有较好的指标、较高的实用性,为功率放大器的设计提供了广阔的思路

本设计的低频功率放大器同时还具有测量显示功率输出、电源供给功率和整机效率的功能。本文首先对功率放大器的课题背景作简要的说明，随后对功率放大器的一些基础知识进行介绍。最后，本文具体叙述实用低频功率放大器的安装与调试，并对电路在工作中易出现的失真情况做了细致的分析。

关键字：前置放大；功率放大；稳压电源电路；

Low frequency power amplifier design graduate paper 【 abstract 】 practical low frequency power amplifier is mainly used for audio signal power amplifier, this paper introduces the weak signal amplifier ability has the low frequency power amplifier, the basic principle of content, the technical route. The main circuit by manostat, preamplifier, power amplifiers, wave transform circuit and the protection circuit of five parts. Manostat primarily for pre-amplifier, power amplifier provide stable dc power. The preamplifier mainly is the voltage scaling. Power amplifier realize current, voltage scaling. Wave transform circuit is will sine signal voltage transform into the requirements of square wave signal. The design of the structure is simple, practical circuit, make full use of the performance of the integrated amplifier. The experimental results show that the power amplifier in bandwidth, distortion degree, efficiency has good index, higher practicability, for power amplifier design offers wide thinking

The design of the low frequency power amplifier and at the same time also has measurement shows power output, power supply power and the efficiency of the function. This paper first to power amplifier background of the topic be briefly and then some basic knowledge of power amplifier is introduced. Finally, this paper describes the low frequency power amplifier specific practical installation and commissioning, and in the work of circuit to occur during the distortion of the situation did meticulous analysis.

Key word: preamplifier; Power amplifier; Stabilized voltage power supply circuit;

目录

1 前言 (4)

2 低频功率放大器系统方案选择 (7)

方案一：采用专用的集成MOS芯片功率放大器 (7)

方案二：采用三极管为核心做功率放大电路 (7)

方案三：采用分立的MOS管做功率放大电路 (7)

3低频功率放大器总体设计 (8)

3.1 低频功率放大器总体设计框图 (8)

3.2 前置放大及滤波电路 (8)

3.3功率放大电路 (11)

3.4采样电路 (12)

3.5 电源电路 (12)

3.6 单片机最小系统电路 (13)

3.6.1 STC89C52单片机简介 (13)

3.6.2 STC89C52单片机最小系统电路 (14)

3.6.3 STC89C52最小系统时钟电路 (16)

3.6.4 STC89C52最小系统复位电路 (17)

3.7 显示部分 (19)

4 低频功率放大器系统软件设计 (20)

5 低频功放测试方案与测试结果 (22)

5.1 输出功率的测量 (22)

5.2 通频带的测量 (22)

5.3输入阻抗的测量 (23)

5.4 输出噪声电压的测量 (23)

5.5 测量、显示功能的测试 (23)

结论 (24)

致谢 (25)

参考文献 (26)

附录1：器件清单 (27)

附录2：程序清单 (28)