冲击测试中电荷变换电路的零漂分析与优化设计  

Zero-drift analysis and optimization design of charge conversion circuit in impact test

作　　者：任勇峰[1] 黄巧峰 贾兴中[1] 谢玲芳 Ren Yongfeng;Huang Qiaofeng;Jia Xingzhong;Xie Lingfang(National Key Laboratory for Electronic Measurement and Technology,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学电子测试技术国家重点实验室

出　　处：《电子技术应用》2019年第12期83-86,共4页Application of Electronic Technique

摘　　要：压电加速度传感器在进行高g值冲击测量时经常出现零漂现象,严重影响了测试结果的精度和可靠性。为解决这一问题,首先建立压电传感器冲击测量时的数学响应模型,分析了测量电路中RC时间常数对零漂的影响。同时针对传输电缆耦合的共模噪声,设计了一种三运放差动电荷放大电路。测试证明,该电路在抑制共模噪声干扰的同时可进行±20 pC的小电荷的检测放大。最后通过恩德福克冲击台进行改进前后的对比冲击测试,验证改进后的设计对冲击测量中零漂抑制切实有效,为工程使用提供一定的参考价值。The zero-drift phenomenon often occurs in piezoelectric accelerometers when performing high-g impact measurements,which seriously affects the accuracy and reliability of test results.In order to solve this problem,the influence of the RC time constant on the zero-drift in the measurement circuit is analyzed by establishing the mathematical response model of the piezoelectric sensor impact measurement.At the same time,a three-op amp differential charge amplifier circuit is designed for the common mode noise of the transmission cable.The test proves that the circuit can detect and amplify the small charge of±20 pC while suppressing the common mode noise interference.Finally,the contrast shock test before improvement was compared with that after improvement by the Endevco impact table in order to verify that the improved design is effective in suppressing zero-drift in the impact measurement,and provides certain reference value for engineering use.

关 键 词：压电加速度传感器 零漂 RC时间常数 共模噪声 差动电荷放大电路 对比冲击测试 

分 类 号：TN712.5[电子电信—电路与系统] TP274[自动化与计算机技术—检测技术与自动化装置]