The Effect of Type of Transient Voltage Suppressor on the Signal Response of a Coupling Circuit for Power Line Communications

The effect of the type of transient voltage suppressor (TVS) used in coupling circuits for surge protecting PLC equipment on the signal response has been studied. The study was focused at TVS devices used in both differential and common mode surge protection. It is found that the gas discharge tube (GDT) has no effect on the communication signal, whilst TVSs that operate on avalanche breakdown attenuate the signal and they also render signal dropout at a particular frequency. Metal Oxide Varistors (MOVs) behave similarly.