【摘要】 针对目前市场上三电极测试产品存在的体积大、价格昂贵等问题,在对三电极工作原理分析的基础上,设计了三电极系统的结构模型,并提出了一种新型的基于STM32微控制器的三电极测试电路。测试电路由恒电位仪电路和电压放大电路构成,以高精密仪器运算放大器为核心器件设计了恒电位仪电路;采用同相并联结构的差分放大电路实现了对微电压的高倍率放大,并用I2C接口的A/D芯片采样放大后的电压信号。研究结果表明,该三电机测试电路的电位误差在1 mV以内,测试电流的下限达到0.1μA;电路可以用来生产便携式三电极测试设备。更多还原

【Abstract】 Aiming at solving problems such as large volume and high prices of three-electrode test products,based on the analysis principle of three-electrode,the structure of three-electrode system was designed and a method was presented to build a circuit which based on STM32 microprocessor. Test circuit was composed by the potentiostat circuit and voltage amplification circuit. Potentiostat circuit whose core device was operational amplifiers with high precision was designed,micro-voltage was amplified by difference amplifier within-phase parallel structure,and A/D converter with I2C interface was sampled the amplified voltage signal. The results indicate that the error of potential is below 1 mV and the circuit can measure current whose value is less than 0.1 μA. The circuit can be used to produce portable three-electrode test equipment.更多还原