前置放大电路中噪声的抑制方法

Noise suppression methods in pre amplifier circuit

在自动测控和通信系统的调试、维修时,必然会遇到多种噪声。为了揭示噪声的根源,采用实验的手法,去观察、分析前置放大电路关键点电压及信号的波形,根据前置放大电路内部结构与实际需要,优化电路的结构,采用优质半导体元器件、光电耦合器和耦合变压器来抑制噪声。实践中,使用这些措施,避免了自控、通信设备信号失真大、共模干扰强,线性差、带宽窄、隔离性能不良等缺点,对提高设备的性能达到了事半功倍的效果。

It is inevitable that experts meet various noise to maintenance and debug in automatic monitoring and control and communication systems. In order to reveal the source of noise, the noise waveform and key point voltage are observed and analyzed in the pre amplifier circuit base on experimental methods. According to structure of the pre amplifier and the actual needs, the noise are filtered base on high-quality semiconductor components, the optimized circuit, optocouplers and cou- pling transformers. In practice, the signal is avoided to distortion common mode interference, poor linearity, narrow band- width, poor isolation and other shortcomings over methods in equipments of automatic control and communications. It has reached a multiplier effect to improve equipment performance.