基于LM3S8962的简易恒流电子负载  

Electronic Load of a Simple Constant-Current Mode Based on LM3S8962

作　　者：季浚涛 姚小翔[2] 施敏[2] 申红明[2] 

机构地区：[1]南通市产品质量监督检验所,江苏南通226011 [2]南通大学电子信息学院,江苏南通226019

出　　处：《南通大学学报（自然科学版）》2012年第4期13-17,共5页Journal of Nantong University(Natural Science Edition)　

基　　金：江苏省高校自然科学基金项目(12KJD510011);南通市应用研究计划项目(BK2011012;BK2012039);南通市社会事业科技创新与示范项目(HS2011015);南通大学自然科学基金项目(10Z022)

摘　　要：为测试开关电源的性能指标,设计了一种基于LM3S8962的简易恒流电子负载.该系统以LM3S8962单片机作为核心控制器,产生D/A输出信号加至功率MOS管IRF540的栅极,通过PI调节改变功率管的栅压从而控制其导通电阻,同时通过采样反馈电路检测端口电压及电流,经A/D转换后送给单片机,形成对电源端口电流的闭环控制,使负载上的电流保持相对恒定.该装置可通过键盘设定输出电流值,可调范围在100～1 000 mA之间设置,分辨率为10 mA,可检测被测电源电流值、电压值等参数,并通过LCD显示,系统具备过压保护功能.该装置结构简单,操作方便,显示界面直观明了.测试结果表明,该电子负载恒流效果良好,系统误差在±1%范围之内.To detect the reliability and properties of switching power supply system, an electronic load working in constant current mode is designed and realized. In the system, a microprocessor of LM3S8962 is used as the core mi- crocontroller, the output signal from D/A is inputted to the gate of the power MOS transistor （IRF540） through a PI regulator and the on-resistance of IRF540 can be controlled by adjusting the gate voltage. In addition, the terminal current can be kept in a constant value by using a close-loop control, in which the terminal current and voltage are measured through a sample-hold circuit and then fed back to LM3S8962 through an A/D converter. The output current of the system can be set ranging from 100 to 1 000 mA with precision of 10 mA, and can be inputted from the key- board. The actual voltage and current can be also measured under an overvoltage protection and then displayed in LCD. Moreover, the designed equipment is characterized by simple structure, friendly interface and convenient opera- tion. The measurement results indicate the equipment enjoys high precision and the error between the set and actual value is less than ±1%.

关 键 词：电子负载 LM3S8962单片机 恒流 

分 类 号：TP271.5[自动化与计算机技术—检测技术与自动化装置]