Point taken about the poor magnetic shielding of amp chassis. I did not mean
to imply that the tubes were immune to the Earth's magnetic field but that
the currents flowing are not of sufficient magnitude, the peak currents in
welding cables are far greater. Rich do you have any photos? If so please
send me them, I am going to ask one of the professors at the University
about this to see if he can offer any explanation.
Conrad
-----Original Message-----
From: 2 [mailto:2@vc.net]
Sent: 07 February 2003 12:06
To: conrad@g0ruz.net; AMPS
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.
Tubes are immune to Earth's magnetic field ?
>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?
Good question. What is the fusing current of #28 Cu ? It must be at
least 15A, and yet the 3-500Z cathode/filament is theoretically not
capable of such a preak emission.
>
Any ideas, Conrad?
>-----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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>
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
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