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[DPRG] Blast from the past - OT and Lightning?

Subject: [DPRG] Blast from the past - OT and Lightning?
From: Jeffrey T. Birt ditto at ipa.net
Date: Sun Jul 8 15:44:21 CDT 2001

While sorting through some of my electronics junk...er...valuables this week
I found some old electronics magazines, one in particular caught my eye due
to the fact it had an article about lightning, the subject of much pondering
on my part recently.  (Hands On Electronics , November 1986) I was just
thumbing through the mag and noticed the first letter in the Letter Box
departments was written by none other than Ralph Tenny!  It seemed rather
funny to me that I bought this magazine 15 years ago and just happened to
see (today) a letter written by someone who I converse with on this email
list.  Isn't technology grand?

Back to lightning....I've been wondering lately if lightning had some sort
of signature, imagine having a 'lightning probe' you could hook to your
scope (hey, I said imagine, don't try this at home kids) what sort of wave
form would it produce.  The magazine mentioned above mentions that a
lightning strike consists of three stokes, each having a negative downward
stroke and a positive upward stoke.  From the chart included (poorly done)
it appears that these pairs of strokes are about 40 ms apart.  Does anyone
out there have anymore info on this, or links \ contacts?  I've spent a few
hours searching the web but most of what I found deals with
studying\preventing lightning damage with proper building grounding.  I
would like to be able to confirm the multi-stoke and timing issue
because.....I want to build a device that would monitor a 110V ac line and
look for this signature and then disconnect, via a relay, a 110v powered
device connect to it, sort of proactive lightning control.  Maybe I'm trying
to re-invent the wheel here, any thoughts?

Jeff Birt
Halfway, Missouri



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