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is lightning attracted to a tesla coil?

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LAN_403

audio:deviant

Fri Jul 17 2009, 04:18PM

Registered Member #2081 Joined: Wed Apr 15 2009, 11:36AM
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Posts: 78

is lightning attracted to a Tesla coil?

GeordieBoy

Fri Jul 17 2009, 04:36PM

Registered Member #1232 Joined: Wed Jan 16 2008, 10:53PM
Location: Doon tha Toon!
Posts: 881

You might get some short bolts (a few feet long) if you build it correctly!

audio:deviant

Fri Jul 17 2009, 04:39PM

Registered Member #2081 Joined: Wed Apr 15 2009, 11:36AM
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Posts: 78

hah yeah this is true.

HV Enthusiast

Fri Jul 17 2009, 04:53PM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
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Avi

Fri Jul 17 2009, 05:38PM

Registered Member #580 Joined: Mon Mar 12 2007, 03:17PM
Location: Melbourne, Australia
Posts: 410

LOL
how about if operating one in a storm, can the 2 sparks 'join'

hvguy

Fri Jul 17 2009, 06:09PM

Registered Member #289 Joined: Mon Mar 06 2006, 10:45AM
Location: Conroe, TX
Posts: 154

Lighting is not "attracted" to anything. People talk about lighting like it's some kind of cognitive force in the sky searching for something on the ground to destroy. Lighting is just an arc from a giant capacitor and is almost completely random in nature. One can trigger lighting just like triggering a spark gap, but "attracting" it is definitely not the right term. It follows the same principals as all other electron flow and will take the path of lowest impedance.

Renesis

Sat Jul 18 2009, 12:18AM

Registered Member #2028 Joined: Mon Mar 16 2009, 08:13PM
Location: Norway
Posts: 319

hvguy wrote ...

It follows the same principals as all other electron flow and will take the path of lowest impedance.

Its not that simple actually. Electrons do flow in the path of lowest impedance, but remember that the impedance between the cloud and ground is infinite until the lightning has reached ground, so the electrons dont give a rats ass until then.

A lightning bolt doesent ionize the entire distance at once like a normal arc. A "step leader" starts within the cloud and travels in short steps (20-40m), jumping between dust particles in the air, raindrops, hail and such.

Think of crossing a lake by jumping between ice sheets. Just like the step leader, you want to take the shortest possible route to the other side, i.e. a straight line. But the location of the ice sheets force you to go zig-zag, and you might end up far from the point where you would end up if you took the shortest possible route.

The step leader often branches into several paths, creating those beautiful upside-down tree formations. Remember that in this stage, current is no more than 10-100 ampere. Step leaders are hardly even visible in daylight, and emit far less light than the actual bolt.

When a step leader aproaches ground the intense electric field starts "pulling" lots of positive streamers from grounded objects. When one positive streamer meets one of the step leader branches, a path of low impedance has been formed between the negatively charged cloud and the positively charged ground. The giant capacitor is shorted out, and a massive electric discharge takes place. The remaining step leaders and streamers are extinguished.

A tall object will be closer to the step leader than the surrounding area, so streamers will form earlier. This gives streamers from tall objects a head start in the race to intersect a leader, and this is why towers and such are more likely to be struck. More likely, not quaranteed! Streamers will also start earlier at sharp points, think of TC breakout points.

If you find this interesting then you should read this article:

A positive streamer streching from a TV tower.
July4leader4

Sulaiman

Sat Jul 18 2009, 07:21AM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3141

Somewhere on 4HV someone recently posted a link to slo-mo lightning - fantastic !

Lightning evidently does 'search' for a discharge path, and can be 'attracted'

Unless your Tesla Coil discharge is higher than surrounding objects don't worry.
(e.g. riding horseback across the Canadian plains with a TC on your head is a BAD idea)
(or even the Australian outback)

I'd be more concerned with the associated rain.

hvguy

Sat Jul 18 2009, 09:47AM

Registered Member #289 Joined: Mon Mar 06 2006, 10:45AM
Location: Conroe, TX
Posts: 154

At the risk of diving into an utterly pointless conversation over semantics, I will stand by my â€œlighting is not attracted to anythingâ€ statement. Using a TC as an example we see that anything with a connection to ground (or significant capacitance to its surroundings since TCâ€™s are RF devices, unlike lighting) will begin to glow with corona as it approaches the topload/break out point. The same thing goes for lighting, just as Renesis has explained so well. It does not matter what is sticking out above the ground, it could be a tree, a tower, or a cow. What does matter is that the object has gotten closer to those leaders than anything else, hence forming that low impendence path mentioned earlier. Of course, the details of this are still a matter of debate as science has not yet determined exactly why lighting, or TCâ€™s and Marx banks for that matter, chose the discharge paths that they do. There are so many environmental variables involved we may never knowâ€¦ So my point is there is no one object that really â€œattractsâ€ lighting better than another, and because of this, and the complicated nature of why lighting struck a specific spot, I feel the term â€œattractedâ€ does not apply, and is used far to often.

Avalanche

Sat Jul 18 2009, 02:01PM

Registered Member #103 Joined: Thu Feb 09 2006, 08:16PM
Location: Derby, UK
Posts: 845

wrote ...
A lightning bolt doesent ionize the entire distance at once like a normal arc. A "step leader" starts within the cloud and travels in short steps (20-40m), jumping between dust particles in the air, raindrops, hail and such.

If these step leaders can be seen, then what is the electron path when the step leader is forming? Either that or what am I missing

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