快速高精度电子元件温度特性测量仪的研制

Development of a Fast and High-precision Measuring Instrument of Temperature Characteristics for Electronic Components

大多数电子元器件的性能受到工作温度的影响,其温度特性对设备稳定性和精确度的影响不容忽视;以半导体致冷器（TEC）为核心,ATMega128A单片机为控制芯片,采用PT100、高精度恒流源和AD7731数模转换器（ADC）组成温度测量模块,运用改进的PID控制算法,以脉冲宽度调制（PWM）方式驱动优化的H桥精确控制加热和制冷功率,结合优化设计的变温腔体,制作了快速、高精度电子元件温度特性测量仪;在-10~80℃之间快速、稳定控制待测元件的温度,控温精度达到±0.2℃;通过计算机控制数字万用表等测量设备,测量了电阻、电容和电感的温度特性曲线;该测量仪还可以用于IC、三极管和LED等元器件的温度特性曲线研究;在实验研究、工业生产和电子实验教学中均具备很高的实用价值。

As the performances of most electronic components are affected by their working temperatures,the temperature characteristics of electronic components are unnegligible.Based on the Thermoelectric Cooler（TEC）and ATMega128 A microcontroller,a fast and highprecision measuring instrument of temperature characteristics for electronic components is designed and produced.The temperature sensor module is made up of PT100,high-accuracy constant current source and AD7731 analog to digital converter（ADC）.The working power is precisely controlled by an optimized H bridge which is driven by width modulated pulses generated by Proportion Integration Differentiation（PID）algorithm.A chamber is also well-designed for temperature control and electrical measurements.The components under test can thus suffer temperatures from-10 ℃to 80 ℃fast with a precision of±0.2℃。By cooperating with computer and measuring instruments such as Digital Multimeter（DDM）and Inductance,Capacitance and Resistance（LCR）meter,the temperature characteristics of LCR,IC,transistor and LED,etc,can be quickly obtained.This instrument has high potential of application in scientific research,industry and experiment teaching in electronics.