RS-232端口光电隔离型电涌保护器

Optical isolation and surge protection of RS-232 port

根据气体放电管和瞬态抑制二极管的保护特性,合理选择退耦元件参数,实现多级SPD间的能量配合,并结合光纤的保护性能设计RS-232接口的保护电路.最后利用雷电冲击试验平台LST-6kV/3 kA、ICGS冲击平台以及DF1641C函数发生器对保护电路进行实验,以验证设计的方案.实验结果表明:在加上保护器件后,通信端口的抗雷电过压能力得到了很大的提高,并且加入该保护电路以后基本不会对原电路产生插入损耗.

Lightning over-voltages are the important reasons for losses in communication port,which make it necessary and urgent to study into the lightning protection of communication port. According to the protection characteristics of gas discharge tube and transient voltage suppressor, the decoupling components are selected carefully to achieve the rational energy correspondence between multi-level SPD. Besides that, optical design is also considered to design protective circuit of RS-232 port. Finally, in order to verify the design scheme, the lightning impact platform called LST-6 kV/3 kA and ICGS and function generator called DF1641C are employed for the experiments. The experiments show that bearing capacity of lightning over-voltage of communication port RS-232 has been greatly improved and will not produce insertion loss to original circuit by adding the protection circuit.