针对航空发动机气路静电传感器输出信号微弱且易受外在及固有噪声影响的特点,设计了一种新型静电信号处理电路。基于静电传感器感应电极的等效电路模型,设计高输入阻抗FET运算放大器作为采集模块,采集输入信号并实现电流值到电压值的转换;进一步利用低噪声测量放大器作为信号放大模块将微弱信号放大;使用直流电池作为电路供电模块,以隔绝外在电缆引入的工频干扰。对电路的增益、带宽及噪声特性进行分析,通过Multisim软件进行电路仿真;最后通过实际信号测试对电路的信号处理效果进行验证。仿真及测试实验结果表明:设计的电路能够有效放大静电信号并减少毛刺噪声,具有良好的处理效果。
For aecoengine gas path electrostatic sensor output signal is weak and susceptible to extrinsic and intrinsic noise characteristics,a new type of electrostatic signal processing circuit was proposed.Based on the equivalent circuit model of electrostatic sensor sensing electrode,an amplifier was designed using a high impedance FET operational amplifier as gathering module to collect input signal to realize A/D conversion.Low-noise instrumentation smplifier was used as signal amplification module to magnify weak signal.DC battery was used as power supply circuit module to isolate the introduction of external cable power frequency interference.The signal conditioning circuit was simulated with the Multisim simulator to investigate the circuit for its gaink,bandwidth and noise properties.At last,circuit signal processing effect was verified through the actual signal test.The simulation and test results show that the designed circuit can effectively enlarge the electrostatic signal and reduce glitch noise,and has good treatment effect.