目前信号电路中使用的电阻、电容元器件普遍采用分立式安装，受质量和寿命所限，必须定期对其进行特性测试和更换。然而，随着铁路行车密度的增大，要点难的矛盾日益突出，更换一次阻容元件极为麻烦，往往因时间仓促易将极性接反，造成设备故障；或急于使用来不及试验，造成设 At present, the resistors and capacitors used in the signal circuit are generally installed in a discrete manner, which is limited by the quality and the life, and must be periodically tested for their characteristics and replaced. However, with the increase of railway driving density, the contradiction between the key points and the difficulty becomes more and more prominent. It is extremely troublesome to change the resistance-capacitance components once and for all. The polarity is often reversed due to the time constraints, resulting in equipment failure; or eager to use too late the test,