埋线探测系统的微小电容检测电路设计

Design of tiny capacitance detection circuit for buried line detection system

利用非平行板电容传感器的边缘效应,设计了浅层埋线探测系统中的微小电容检测电路,实现了准确探测埋线位置的目的。将交流电桥作为核心电路,实现了将动态微小电容量转换为放大直流电压量的功能;对电路进行仿真,得到了输入电容与输出电压两者之间的规律;在实验板上进行测试实验,并对实验数据进行了处理与分析。实验表明:设计的电路实际性能与理论仿真结论相一致,在频率为10 k Hz的正弦波作用下,该电路的电容检测灵敏度可达0. 1 V/p F,满足浅层埋线探测系统的灵敏度要求。

Using the edge effect of non-parallel plate capacitive sensor,tiny capacitance detection circuit in shallow buriedline detection system is designed to achieve the purpose of accurate detection of the position of the buried wire. Using the alternating current bridge as the core circuit,the function of converting the dynamic microcapacitance into the amplified direct current voltage is achieved;the circuit is simulated to obtain the law between the input capacitance and the output voltage;the test is carried out on the experimental board,and the experimental data is processed and analyzed. Experiments show that the actual performance of the designed circuit is consistent with the theoretical simulation conclusion,the capacitance detection sensitivity of the circuit can reach0. 1 V/p F with 10 k Hz sine wave,which satisfies the sensitivity requirements of the shallow buried detection system.