conduit bonding

[physis]

Re: conduit bonding

Al'

I think my reaction about antennas comes from your use of "generated" instead of induced. I was thinking there's something else being added to the system. I could call a generator an inducer but it's unorthodox.

I've reread your post and I should have understood what you were saying the first time.

It only takes 2.65 millihenrys to raise the impedance 1 ohm at 60 cycles.

After doing the math I think it makes sense to shunt the conduit.

 

[physis]

Re: conduit bonding

Al,

I think you're talking about being able to produce any waveform using the right combination of sine waves. (You can make a square wave that way). But that doesn't mean that lightning is made from sine waves.

I don't disagree that a lightning strike would look pretty messy on an oscilliscope.

Hurk,

I thought that when the points closed the primary charged and when they opened the magnetic field collapsed with the only path being the secondary through the plug gap to the block. No sine wave.

It's a great analogy for lightning.

It reminds me of a 25 amp 50 volt load bank I was involved with. 5 wire wound 500 watt resistors in parallel connected through a relay. When the first one was assembled we tested it and had a problem disconnecting the load. The relay would not stop arcing unless power was removed or the relay was reengaged. It tured out that the wire around the resistor cores were not straight wire but coiled wire, sort of like a slinky. At that current there was enough back emf to ionize the air around the relay contacts and maintain current flow across the air gap.

Maybe it's not all that relevant but it's related to induction, ionization and lightning.

I've really never given lightning as much thought as in the last couple days. You guys seem to have studied the subject pretty thoroughly.

[ June 01, 2003, 06:35 AM: Message edited by: physis ]

 

[brian john]

Re: conduit bonding

A good source of information on lightning for those interested.


Uman. M., All About Lightning, Dover Publications, 1986.

 

[hurk27]

Re: conduit bonding

Here are some good web sites that explaine better than I can.

http://www.lightningsafety.com/

http://lightning-protection-institute.com/

http://www.lightningstorm.com/

http://www.lightningsafety.noaa.gov/

http://thunder.msfc.nasa.gov/

http://www.sky-fire.tv/index.cgi/Sprites.html

http://www.nssl.noaa.gov/researchitems/lightning.shtml

http://www.nws.noaa.gov/om/hazstats.shtml

[ June 03, 2003, 12:06 AM: Message edited by: hurk27 ]

 

[don_resqcapt19]

Re: conduit bonding

Remember that our understanding of lightning and lightning protection systems is so poor that at one point the NFPA was going to drop NFPA 780, The Lightning Protection Code, because of the lack of technical justification for this code.
Don