山东电子方案设计书论文.doc

编号:026F002
2012年山东省大学生电子设计竞赛
F题:直流电子负载
学校:潍坊学院
参赛学生:国志成(**********)
李世斌(**********)
姜立奎(**********)
专业:自动化
自动化
自动化
指导老师:侯崇升

直流电子负载
摘要:本设计从直流电子负载系统方案分析入手,详细讨论了整个系统的硬件电路和软件实现,最终使用PWM技术控制MOS管的工作状态实现了电子负载的恒流、恒压、恒阻三种工作方式,并且参数可设置。为便于控制的实现和功能的扩展,采用了MSP430 单片机作为核心控制器,设计了电压、电流检测电路、键盘电路、显示电路和驱动电路,通过软、硬件的协调配合,实现了整个设计。通过运放、PI调节器及负反馈控制环路来控制MOSFET的栅极电压,从而达到其内阻变化。这个控制环路是整个电路的核心实质,MOS管在这里既作为电流的控制器件同时也作为被测电源的负载。控制MOS管的导通量,其内阻发生相应的变化,从而实现了电子负载的三种工作模式。
关键词:电子负载,PWM技术,PI调节,MSP430
ABSTRACT: From DC electronic load system solutions, the design analyzes, detailed discussion of the entire system of hardware circuits and software implementation, end-use PWM technique to control the working status of the MOS transistor electronic load, constant current, constant voltage, constant resistance work in three ways and parameters can be set. In order to facilitate the realization of the control and use the MSP430 MCU as the core controller design voltage, current detection circuit, keyboard circuit, display circuit and driver circuit, hardware and software coordination to achieve the entire design. Op amp, the PI regulator and negative feedback control loop to control the gate voltage of the MOSFET, so as to achieve its resistance changes. This control loop is the core essence of the entire circuit, MOS, both as a current control device as well as the measured power load here. Control MOS transistor conduction flux, the resistance change accordingly, in order to achieve the three operating modes of the electronic load.
KEY WORDS: electronic load,PWM technique,the PI regulator,MSP430
目录
4
4
4
4
5
5
5
MOSFET驱动控制器件的选择 5
6
6
6
7
、保护单元 8
9
电平转换电路 9
10
11
11
11
12
13
测试仪器 13
13
工作状态测试 13
发挥部分指标测试 16
: 16
4.