地铁轨道工程车PLC高/低电平输入信号隔离降压板设计

Design of High/Low Level Input Signal of Isolation and Voltage Reduction Circuit Board of PLC for Metro Track Engineering Car

轨道工程车电气控制系统的高/低电平信号电压一般为DC 110 V/0 V,而PLC高/低电平信号输入接口额定电压一般为DC 24 V/0 V和AC 220 V/0 V,因此,PLC无法直接应用到轨道工程车的电气控制系统中。为解决输入接口电压等级不匹配的问题,研发设计PLC高/低电平输入信号隔离降压板。隔离降压板主要由TLP521-4型光耦芯片、发光二极管、电阻和接线端子组等电子元件构成,经仿真试验验证,效果良好。

The high/low level signal voltage level of the electrical control system of the track engineering car is gener⁃ally DC110 V/0V,while the rated voltage of the PLC high/low level signal input signal interface is generally divided into DC24 V/0V and AC220 V/0 V,so PLC cannot be directly applied to the electrical control system of the track en⁃gineering car.In order to solve the problem of mismatch of input interface voltage levels,the PLC high/low level input signal isolation and voltage reduction circuit board was developed and designed.The isolation and voltage reduction circuit board is mainly composed of TLP521-4 optocoupler chip,light-emitting diode,resistor,terminal group and other electronic components.The simulation results show that the isolation and voltage reduction circuit board has good effect.