基于MSP430F169单片机的直流电子负载的设计

Design of DC electronic load based on the MSP430F169 microchip computer

为了智能测量和研究直流稳压电源、蓄电池等电源的负载特性,设计了一台以TI公司的16位超低功耗单片机MSP430F169为中心控制的直流电子负载。外置16位D/A转化芯片ADS1115实时高精度采样电源电压和电流信号,经过单片机程序控制,单片机内置12位D/A转换电路输出一个直流信号并经过运放放大后驱动功率MOS管工作。MOS管作为功率消耗元件,整个电路构成了电压和电流闭环调节系统,可工作于恒压和恒流2种模式。被测电源的输出电压、输出电流和负载调整率可以实时测量并显示在图形液晶显示屏上,电流和电压的测量精度可达(0.02%±0.02%FS)。电子负载人机交互友好,测量精度高,单片机外围电路简单,可靠性高,扩充性好,具有很强的实用价值。

In order to intelligently measure and study the load characteristic of a DC regulated power supply or a battery,an electronic load,in which a 16 bits ultra low power consumption micro chip computer MSP430F169 is used as central control chip,is developed.Output voltage and current of the measured power supply is in real time and high accuracy sampled by the exterior A/D chip ADS1115,and by the programming of MSP430F169,a DC voltage signal from the interior D/A circuit of MSP430F169 is amplified and used to drive the power MOSFET which is acted as the power consumption component of the electronic load circuit.Thus all these constitute a current and voltage closed loop regulated system which can operate in constant voltage mode or constant current mode.The voltage,current,and load regulation of the measured power supply all can be in real time measured by the system and displayed by the graphic LCD,and the measurement accuracy of the voltage and current can reach a value of（0.02%±0.02%FS）.Friendly human computer interaction,high measurement accuracy,and simple exterior circuit of MSP430F169 of the designed electronic load circuit,make it have high stability,good expandability and highly practical value.