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.