At 02:27 PM 12/8/2006, you wrote:
>There are surge protectors for phone lines, Satellite coax lines as well
>as Cable TV coax lines. Just google your area of concern and you'll
>find lots of vendors.
>
>Most companies recommend a whole house protector followed by individual
>units at all electronic equipment service areas.
After seeing the analysis in the book, I'd really question the need
for individual units at point of use (at least as they are
implemented in the usual consumer devices). What might actually be
useful is something like a transient clipper at the service entry,
followed by a suitable low pass filter (to turn a high voltage narrow
spike into a long duration bump).
Likewise, at point of use, a good low pass filter might be a more
useful device than a transient suppressor. Of course, such devices
are substantially more expensive to build than a plug strip with a 30
cent MOV. The well equipped scrounging ham, on the other hand, should
be able to find lots and lots of line filters from Corcom, etc.,
available surplus and wire them up appropriately. That lightning
transient, after all, has most of the energy up in the hundreds of
kHz range and higher.
{BTW, I suspect that it's all those filters that are present in most
consumer equipment these days that's why Standler's test data showed
that 1000V short duration spikes didn't cause any troubles}
Excepting the "nearby lightning strike" scenario, there isn't much
way for a fast transient to be induced into your inside wiring. This
is assuming you don't have a big "noise generator" inside your house,
in which case, you should be focussing on stopping the transients at
the source. (Come on, just build that faraday cage for your 5kVA
tesla coil and stop operating the electromagnetic quarter shrinker in
the living room!)
OTOH, I can plausibly see a lot of surge/sag kinds of behavior (i.e.
Vrms going up to 130 for a second) and conducted transients (from
switching and/or lightning somewhere in the power transmission/distribution).
I readily confess that I live in a relatively lightning free zone
(southern California) but we DO get a lot of line transients,
especially when it's windy. (Tree touches line, faults, breaker
trips, then recloses, propagating 50% amplitude transients hither and yon)
Jim
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