摘要
提出一种基于比率法的高精度电桥电路,用于测量电阻传感器中的高精度电阻。该电桥电路是基于模数转换器的数字量输出,采用模拟输入电压与参考电压比率的方法,将电桥的不平衡输出经放大后作为模数转换器的模拟量输入,将电阻式传感器相同一侧另一桥臂两端的电压差经放大后作为模数转换器的参考电压,经过模数转换后两者比率的数字量作为系统的输出。经过该电路处理后,电阻信号与系统的输出之间成线性关系,并克服了供电电压波动对电阻测量结果的影响,消除了系统的零点漂移和温度漂移。该电桥电路具有高准确度的电阻测量性能。
A high-precision bridge circuit based on ratio method is proposed to measure high-precision resistances of resistive sensors. Based on the digital output of ADC, the ratio of the ADC＇s analog input voltage and reference voltage is adopted. The amplified unbalanced bridge output serves as the ADC＇s analog input. The amplified voltage difference between both ends of another bridge arm of the same side is used as the reference voltage of ADC. After analog-digital convension the digital output of ADC is as the system output. Through processing of the bridge circuit, a linear relationship between the resistance signal and the output of the bridege circuit is obtained, and the influence of supply voltage fluctuation and the system＇s zero drift as well as the temperature drift are eliminated. The bridge circuit has a better measurement performance for the high-precision resistances.
出处
《上海计量测试》
2016年第1期39-42,共4页
Shanghai Measurement and Testing
