NavList:

Alan,

The problem, as I understand it, is at least two fold: On the one hand you have damage caused by direct lighting strike. No much to do here as virtually all electronics will get fried by even a short burst of 10kV although a lighting arrestor may help here. On the other hand is the magnetic field produced by the discharge to ground. This field will in turn induce really large voltages on any metal surfaces including electronic boards, irrespective of their connection to antennas and such. Some calculations put this induced voltages (for a lightning strike within 5 meters or so), in the order of several hundred volts for boards of modest size (postcard size). This induced voltage is what is ultimately responsible for destroying the electronics. This induction can be mitigated by intercepting the magnetic field with an appropriate magnetic shielding material.

Alejandro

On Jul 19, 2012, at 2:13 PM, Geoffrey Kolbe wrote:

>
>
>> Richard:
>>
>> I realize that the voltage involved in lightening strikes is extremely high, however re ship's electronics being knocked out by one such, couldn't the electronics be grounded or otherwise protected, or does the voltage involved preclude such attention?
>>
>> Alan
>
> One of Murphy's laws goes: "Any device whose purpose is to protect a transistor from blowing will itself be protected by the transistor blowing first."
>
> In my experience, I have found the law to be invariably true...... unfortunately.
>
> Geoffrey
>
>
>
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