On Jul 24, 7:35*am, "Szczepan Bialek" wrote:
*"K1TTT" ...
On Jul 23, 8:48 am, "Szczepan Bialek" wrote:



"Jim Lux"
...

IIRC the purpose is to primarily drain off the static charges so the
gnd-cloud potential difference is minimized. A direct strike will
usually
just melt whole house wiring, etc. etc.

Not true.

The cloud has SO MUCH charge you don't stand a chance of bleeding it
off.

Each cloud has a charge and the all is flowing to the ground. But only
20%
as the direct stroke.

The rule is simple. A mast with the polished ball on the tip attract the
direct stroke (polished ball do not dissipate).
A mast with many sharp spikes dissipate the static charge and eliminate
the
direct strike.
wrong, sharp spikes are designed to start an upward streamer that

connects the downward leader to the lightning rod. *that is why they
have a sharp point, to reach the breakdown field gradient before
anything else around them.

But before the steamer is the dissipating: " IIRC the purpose is to
primarily drain off the static charges so the

gnd-cloud potential difference is minimized"

Direct strikes are typically around 20 kA, and can be as high as 100kA.
Both can be adequately carried by the usual AWG6 wire, because the
current
pulse only lasts a few microseconds.

It is the oscillating current which has a canal in the air. It is not
obliged to flow only in the wire.
S*
normally they don't oscillate, it is a mono-polarity pulse.

Normally in ALL sparks current oscillates: " The storm detector is a radio
receiver .
"The device was invented in 1894 by Alexander Stepanovich Popov. It also was
the first radio receiver in the world.
Ground-based and mobile detectors calculate the direction and severity of
lightning from the current location using radio direction-finding techniques
together with an analysis of the characteristic frequencies emitted by
lightning"

S*

you like quoting stuff off the web don't you... too bad you don't
understand the basic physics behind it. no, the spark current doesn't
have to oscillate to be picked up by a radio receiver. The short
pulse, yes even one that doesn't oscillate itself, is made up of a
large number of sine waves added together, it is those that can be
picked up by radio receivers. it is also possible at a large distance
to determine the polarity of the lightning stroke as they can be
either positive or negative strokes, that type of distinction wouldn't
be needed if they oscillated.