摘要
为了解决现有微电阻测量中采用的测试电流过大、精度不高的问题,给出了一种低测试电流的微电阻测量系统的设计。采用高精密恒流源作为电流源,具有很好的稳流特性、低漂移及低噪声的运算放大器ICL7650和OP07ADJ构成精密放大电路,通过数据的实时采集、A/D转换,由单片机进行数据的处理和显示,主要对微弱信号的放大原理以及测量的可行性进行了分析。通过实验验证,实现低测试电流下微电阻的准确测量,当测量电阻为0.05～0.5Ω,测量电流为5～10 mA时,测量精度达到1/1 000。
In order to solve the problem of the excessive current and low precision in micro-resistance measurement at present,a design for the micro-resistance measuring system of the low measuring current is introduced.Taking the constant current source with high precision as current source,the precision amplifying circuit based on a operational amplifier ICL7650 and OP07ADJ with very low drift and low noise,through the real-time data acquisition and A/D converter,the data are processed and displayed by MCU,and the magnify principle of the weak signal and the feasibility of the measurement are analyzed.The experiment shows that the micro-resistance is precisely measured under the low measuring current,the measuring accuracy reaches 1/1 000 when the measuring resistance is 0.05 ～0.5 Ω and the measuring current is 5～10 mA.
出处
《光电技术应用》
2011年第5期68-71,共4页
Electro-Optic Technology Application
基金
陕西省教育厅自然科学基金(05JK214)
关键词
微电阻
低测试电流
精密恒流源
low resistance
low measuring current
precision constant current source
