[time-nuts] GPS-Attached Equipment Lightning Protection

[Attila Kinali]

On Sat, 01 Mar 2008 10:12:39 +1030
Matthew Smith <matt at smiffytech.com> wrote:

> And this was the reason for my original query - what I don't want is for
> anything to get to the computer/LAN.  There has been considerable
> discussion on the 1-Wire Weather list about equipment getting toasted
> due to strikes on/near anemometers, etc.

If you want to have a really secure system use:

1) a gas discharge tube at the point where the cable
enters the building. Note, that you should ground the
shield of the cable at this point.

2) a varistor diode a few meters inside. The distance is
needed so that the time the tube needs to form a discharge
is shorter than the time the surge needs to travel to the
varistor.

3) a zener diode directly at the input of your receiver.

With that and good ground connection strategy, you should be
pretty much safe against all lightning strikes.

Of course, given that your building has a reasonable lightning
protection. Otherwise the induced currents will fry any electronics
no matter how well your protection circuits are.

				Attila Kinali
-- 
Praised are the Fountains of Shelieth, the silver harp of the waters,
But blest in my name forever this stream that stanched my thirst!
                         -- Deed of Morred