摘要信号发生器能够产生符合参数要求的电信号，信号的幅值、频率和波形都是可调 节的，其在电子测量中是最基本和应用最广泛的测量仪器，它的功用主要表现在以下 几个方面：（1）产生测试信号：产生符合参数要求的各种波形。（2）信号调制功能： 改变信号的幅值、相位或频率，把低频信息嵌入到高频的载波信号中,得到的信号可 以传送从语音、到数据、到视频的任何信号[1]。（3）设备检测：选用恰当的信号发生 器与验电器连接，通过验电器的反应来判断出其是否有故障。84959
信号发生器是一类重要的测量仪器，在实践生产中有着广泛的应用。这次设计的 低频信号发生器，该系统主要由单片机 STC89C51，数字/模拟转换器 DAC0832，运 放电路 LM358，液晶显示电路 LCD1602 和键盘电路等模块组成的。可通过按键选择 输出正弦波、方波、三角波、矩形波四种不同波形，调节出不同频率以及改变波形的 幅值。
本次系统的设计主要要完成以下几种工作：（1）选择正确的设计方案；（2）绘制 原理图；（3）完成程序的编译与调试；（4）电路图的仿真测试；（5）实物制作与调试。
本设计系统具有结构简单，操作方便，性价比高等特点，可用于需要低频信号源 的场所，有一定的实用价值。
毕业论文关键词：信号发生器；单片机 STC89C51；D/A 转换；
Abstract The signal generator can generate electrical signals that meet the requirements of the parameters, and the amplitude, frequency and waveform of the signal can be adjusted， which is the most basic and most widely used in electronic measuring instruments
measurement。 Its function is mainly manifested in the following aspects: 1)Generate test signals: produce all kinds of waveforms that meet the requirements of the parameters。2) Signal modulation function: change the amplitude, phase, or frequency of the signal。, the low frequency information is embedded into the carrier signal of the high frequency, and the signal can be transmitted from the voice, to the data, to any signal of the video。3) Equipment testing: Selection the appropriate signal generator to connect with the electroscope, by the reaction of electroscope to determine whether there is a fault
Signal generator is an important measuring instrument, It has been widely used in the production of practice。 I designed a low-frequency signal generator, the system is mainly composed of single chip microcomputer STC89C51, a digital / analog converter DAC0832, the operational amplifier circuit LM358, liquid crystal display circuit LCD1602 and keyboard circuit and other modules。 The system wave output can be selected via buttons, square, triangular, rectangular four different waveforms and adjust the different frequency and change the amplitude of the waveform。
The system has the characteristics of simple structure, convenient operation, high cost performance and so on。 It can be used for the needs of low frequency signal source and has a certain practical value。
Key words：signal generator; single chip STC89C51; D / A converter
目录
第一章 绪论 1
1。1 课题背景 1
1。3 本课题的目的和内容 2
第二章 信号发生器的方案设计 3
2。1 方案的初步构思 3
2。2 主要元件的选择 3
2。3 硬件电路设计方案 4 STC89C51单片机信号发生器的设计+电路图+程序:http://www.youerw.com/zidonghua/lunwen_101312.html