【摘要】 设计了一种高精度可自动调整量程的电阻测量仪。本测量仪采用高稳定性的2mA恒流源作为激励加载在待测电阻上,并利用由数控电阻MAX5400构成的数控放大模块对待测电阻两端的电压进行放大,最后由基于ARM Cortex-M3内核的STM32F103RE微控制器内部的ADC对放大后的电压进行A/D采样变换,从而计算出待测电阻阻值。微控制器可以通过SPI总线对数控电阻进行控制,从而改变数控放大模块的放大倍数,根据待测电阻自动的改变测量量程。试验表明,本文设计的测量仪大大提高电阻测量精度,误差小于1%。更多还原

【Abstract】 This paper designs a resistance meter with high-precision which can adjust range adaptively.The meter uses a high stable 2mA constant-current source as an incentive to the to be measured resistor,and utilizes numerical control amplifier module consisting of numerical controlled resistance MAX5400to amplify voltage of the two sides of experimental resistor,and the ADC included in STM32F103RE microcontroller which is based on ARM Cortex-M3core conduct unscented transform to amplified voltage in the final stage,and calculates experimental resistor value.The microcontroller can make control resistance online by SPI bus,and then change magnification of numerical controlled amplifier module,thereby determine the measurement range adaptively.By experiment,the measuring meter designed by this paper can measure resistor with high-precision,the error is less than 1%.更多还原