A good brand of connectors COLIN named " VIAGRA " use the blue ones . Dont
need EMF.....
Jos
----- Original Message -----
From: "COLIN LAMB" <k7fm@teleport.com>
To: "AMPS" <amps@contesting.com>; "Jeffrey Madore" <K1LE@arrl.net>
Sent: Friday, February 07, 2003 8:16 PM
Subject: Re: [Amps] Re: Voodoo "EMF' forces from grid current pulses
> When the high voltage across the room arcs, I jump too - even though there
> is no connection. Of course I jump more if I am connected. I think if the
> arc was big enough, I would have EMF in my pants.
>
> K7FM
>
> > [Original Message]
> > From: Jeffrey Madore <K1LE@arrl.net>
> > To: AMPS <amps@contesting.com>
To: <amps@contesting.com>
> > Date: 2/7/03 11:33:24 AM
> > Subject: Re: [Amps] Re: Voodoo "EMF' forces from grid current pulses
> >
> > I used to wonder if the attraction to the earth's magnetic field was a
> > plausible explanation to the jumping cables. I came to the belief that
it
> is
> > not, as the earth's field is not that strong at any given location. For
> > example, I have a mag mount that is so strong that I need to use two
hands
> > and considerable force to apply it to the roof of my van, lest I cause
> body
> > damage. The magnet is not noticeably attracted to earth. A magnetic
> compass
> > needle is very light yet it's reaction to the earth's field is not
> > particularly violent. In fact, it will happily point to the barrel of my
> > rifle if I'm not careful.
> >
> > As far as shielding, enclosures, etc. I see those as possibly enhancing
> > magnetic / mechanical forces caused by a high current pulse within the
> > shielded area. Aluminum makes a great magnet.
> >
> > I used to do a classroom / lab demonstration where I would remove the
> rotor
> > from a 2hp 3 phase motor and place an aluminum can in the stator. Most
> > students (all adult engineering, electricians, test specialists, etc)
> would
> > guess that the stator's field would not have any effect on the aluminum
> can,
> > as it was non ferrous. I would then energize the stator and the can
would
> > spin so fast that it would shoot out of the end of the stator. People
were
> > then willing to understand that the aluminum bars cast within the iron
of
> > the rotor, were the cause of magnetic action (through induction) and
> torque.
> >
> > I say all that to get back to inductance and transformer theory: When an
> AC
> > current flows in a conductor (primary) it causes a changing magnetic
> field
> > which induces a potential in anything conductive (secondary), that is
> within
> > the effects of that field.
> >
> > If there is an electrical circuit, current will then flow in the
> secondary.
> > In the case of the aluminum can, these were circulating currents. Now,
the
> > secondary current is nearly 180 degrees out of phase with the current in
> the
> > primary, thus the magnetic field produced by the secondary current is
also
> > out of phase with the primary's field. This leads to maximum mechanical
> > forces.
> >
> > So, could a large current flow between two elements within a vacuum
tube,
> > cause mechanical distortion of other fragile elements within that tube?
I
> > believe so.
> >
> > 73, Jeff - K1LE - CT ><>
> >
> >
> > ----- Original Message -----
> > From: "Conrad G0RUZ" <conrad@g0ruz.net>
> > To: " AMPS" <amps@contesting.com>
> > Sent: Friday, February 07, 2003 6:17 AM
> > Subject: RE: [Amps] Re: Voodoo "EMF' forces from grid current pulses
> >
> >
> > > This can be easily explained, the welding cables are subject to the
> earths
> > > magnetic field and any other localised magnetic fields, that's why
they
> > jump
> > > about. The question is, would this happen in a shielded enclosure (amp
> > > chassis) and with the magnitude of current flowing in the grid during
a
> > > fault condition? I am still sceptical. One thing's for sure, something
> > > happens, but what?
> > >
> > > 73
> > >
> > > Conrad G0RUZ
> > >
> > > -----Original Message-----
> > > From: amps-bounces@contesting.com
[mailto:amps-bounces@contesting.com]On
> > > Behalf Of Jeffrey Madore
> > > Sent: 07 February 2003 04:24
> > > To: 2; MorgusMagnificen@aol.com; AMPS
> > > Subject: Re: [Amps] Re: Voodoo "EMF' forces from grid current pulses
> > >
> > >
> > >
> > > >
> > > > >I strongly challenge this assertion. I know of no mechanism within
> the
> > > realm
> > > > >of classical EM field theory to account for this. I am assuming you
> are
> > > > >referring to the normal force that would accompany two
> current-carrying
> > > > >conductors which are in parallel proximity to each other.
> > > > >
> > > > Have you ever been to a welding shop and observed what happens to
> > > > arc-welder cables when an arc is struck? I have and I saw the
cables
> > > > jump about on the floor.
> > >
> > > Yea verily, Rich!
> > >
> > > In my past life I did high current trip testing on 480 volt circuit
> > > breakers. 50,000 amps was not unusual but even much lower currents
would
> > > make welding cables jump off of the floor.
> > >
> > > I remember experimenting with a fairly large 480/120 3 phase lighting
> > > transformer, with a dead short on the secondary and 208 volts applied
to
> > the
> > > primary via a pretty large motor control contactor and momentary push
> > > button. It was a "hit the button while peaking around the corner" type
> of
> > > experiment. We were able to draw about 2000 amps momentarily on the
> > > secondary which really made a set of welding cables jump.
> > >
> > > In my experience, a single conductor doesn't need any other conductor
> near
> > > it to display mechanical force when high current is applied. The self
> > > inductance of the cable and resulting cemf produce sufficient magnetic
> > > reaction to make the cable jump if it is not secured. Very interesting
> to
> > > look at the Z of a 4/0 welding cable...
> > >
> > > I've often found that if our engineering theories couldn't explain
what
> > > appeared to take place in reality, then we needed to look deeper into
> the
> > > matter.
> > >
> > > 73, Jeff - K1LE - CT
> > >
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> >
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>
> --- COLIN LAMB
> --- k7fm@teleport.com
> --- EarthLink: The #1 provider of the Real Internet.
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