电子大赛-直流电子负载教材.doc

直流电子负载 摘要：该系统是以制作一台实现恒压、恒流、恒阻模式的直流电子负载为目的。系统采用STM32F103为主控芯片，使用OP27作为驱动装置，并配合AD81115和TLV5616实现电压转换。工作时，采集的模拟信号经放大电路后送入转换电路生成数字信号，再送入单片机进行PID算法处理，不断调节，输出值经TLV5616 DA电路再转化为模拟信号，最后通过放大电路驱动MOSFET管，经液晶模块同步显示最后值。经过实际调试，此设计能够检测被测电源的电流值、电压值和电阻值，能够实现恒压、恒流、恒阻模式且满足误差要求。 关键词：电子负载 恒压 恒流 恒阻 STM32 AD Abstract : n order to make a DC electronic load, the system can achieve the constant current, constant voltage and constant resistance model . The system’s main control chip is the STM32F103, using the OP27 as driving device and the voltage are transformed through AD81115 and TLV5616. When it is working, the sampling voltage is transformed into the digital signal through the AD81115. The output signal is disposed and adjusted constantly by MCU’s PID algorithm. The out-putting voltage is transformed into analog by the DA TLV5616. At the last, the MOSFET is drived by the amplifier circuit. The LCD module synchronously displays the voltage and current value. Through actual detection, this design can detect the measured power supply current value, voltage value and resistance and realize constant current, constant voltage and constant resistance model as well as can satisfy the error requirements. Key words: The Electronic load, Constant voltage, Constant current, Constant resistance, STM32 , AD 目录 一、设计要求 1 二、总体方案设计 1 2.1总体方案概述 1 2.2总体结构设计 1 三、具体方案设计 2 3.1方案比较与论证 2 3.1.1电源选择方案 2 3.1.2MCU的选取 2 3.1.3显示电路方案设计 2 3.1.4模式转换方案 2 3.1.5输入方案