简易直流电子负载设计及测试

A Simple DC Electronic Load

该文设计了以单片机C8051F020为控制核心的简易直流电子负载。电子负载采用恒流工作模式,恒流方式通过单片机内部DA输出控制NMOS管等电路产生恒定电流,当直流稳压电源电压在一定范围内变化时,流过本直流电子负载的电流保持恒定。在恒流模式下的设定电流非常精准。在不同设定电流下,电子负载两端电压变化10V时输出电流变化值能够控制在0.9%以内。过压保护阈值电压18V附近。电子负载两端的电压,电流测量精度均可满足。同时本简易直流电子负载可以工作在恒阻方式。可设定电阻,并可测得电子负载两端电压与电流为线性关系,即是恒阻模式下的电阻值。

This paper introduces the design of a simple DC electronic load by single-chip microcomputer of C8051F020. The electronic load is beads on a constant current mode. Constant current controls NMOS tube circuit to generate a constant current with DA on the MCU. When voltage supplied by the DC power changes within a certain range, the current going through the DC electronic load is a constant. In the constant current mode, setting current is very accurate. When the terminal voltage off Electronic load changes 10V, the changing value of output current can be controlled less than 0.9%. Overvoltage protection volt- age is about 18Vo Meanwhile, the simple DC electronic load can work in the constant resistance mode.