Weather forecast for Toronto, Canada 15-day query

When it rains heavily, if there is no lightning and thunder outside, you can turn on the computer, which has no effect.

If the associated lightning is to be prevented, there are two situations in which lightning enters the room: from the power line and from the signal line.

Power invasion

In modern buildings, we can see lightning protection devices. When the building is directly hit by lightning, strong current is introduced into the ground along the grounding lead, which prevents the lightning from damaging the building. We also need to take some necessary lightning protection measures indoors. Technically, we need to install lightning protection devices for power supply on computers, household appliances and communication equipment. But in fact, because high-rise buildings have relatively perfect lightning protection measures, users in buildings generally do not need to consider lightning protection from the perspective of power supply.

Signal line intrusion

The invasion here is mainly lightning surge caused by induction lightning. Induction lightning generally comes from lightning strike to the ground and cloud-to-cloud discharge, among which the induced surge voltage generated by lightning strike to the ground is large, and electronic information equipment within 500 meters may be damaged by it. According to the theory and practical experience of lightning electromagnetic pulse, it is proved that the damage of electronic computers and other information equipment is mainly caused by lightning induced surge voltage, which can introduce the induced surge voltage wave into the equipment through various signal leads and destroy its chips and interfaces. Therefore, signal lightning protection devices should be installed between signal lines.

When lightning strikes the wire, strong lightning current and high voltage will enter the user's room with the wire. The lightning voltage is about 654.38+0000V, and the rated voltage of any electrical appliance is not so high, so it is easy to burn electrical appliances. Secondly, the electromagnetic harmonics generated by lightning will also cause harmonic overvoltage and damage electrical appliances. Therefore, in the weather with thunder and lightning, the electrical appliance should be turned off and unplugged to avoid unnecessary damage to the electrical appliance.