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27th July 2012, 03:11 AM  #25001 
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My gut tells me Frank's lower figure is closer Inductance is a function of the enclosed loop area  we can't get an accurate estimate from just knowing the length of wire.
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27th July 2012, 03:18 AM  #25002 
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27th July 2012, 03:21 AM  #25003 
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Yes, although Ed Simon said he had to fix a lot of his mistakes, Whitlock had electricians pull out hot and neutral from conduit and twist them together, to reduce the differential fields induced in the safety ground. I suspect that would have quite an effect on our inductance "estimates".

27th July 2012, 03:35 AM  #25004  
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Quote:
Edit: Anyway, even for the biggest number of 150 microhenry inductive impedance would be no more than 20 Ohm on 20 kHz frequency. For 17 microhenry even less, I suppose?
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The Devil is not so terrible as his math model is! Last edited by Wavebourn; 27th July 2012 at 03:40 AM. 

27th July 2012, 03:38 AM  #25005 
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Yep  so differential mode inductance is reduced by having the wires in proximity.
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27th July 2012, 03:42 AM  #25006 
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Anyone tried measuring, what a concept?
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27th July 2012, 03:46 AM  #25007 
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I've measured speaker cables  they have similar conductor spacing to mains wiring and they run around 1uH/m round trip inductance as a ballpark.
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27th July 2012, 03:46 AM  #25008 
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And smaller mean time between fatalities. MTBF
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27th July 2012, 03:51 AM  #25009 
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Just to further mix this up I grabbed a 50' extension cable and measured it (shorted at the far end) at 100 Hz, 1KHz and 100 KHz and for all three I got 3.5 uH.
Remember a wire in space has no inductance. Its only in a circuit that it has inductance. And the closer the two conductors are the lower the inductance.
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27th July 2012, 03:55 AM  #25010 
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I was thinking 'mean free path or time between collisions' myself  MTBC.
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