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Old 27th July 2012, 03:11 AM   #25001
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Originally Posted by Wavebourn View Post
Did I miss anything?
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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Old 27th July 2012, 03:18 AM   #25002
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Boy! This is great. We have 15uH, 50uH, 140uH and 150uH. Good thing you all dont do design work for a living.
It used to be that in astrophysics an order of magnitude was pretty acceptable
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Old 27th July 2012, 03:21 AM   #25003
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Originally Posted by abraxalito View Post
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.
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".
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Old 27th July 2012, 03:35 AM   #25004
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Quote:
Originally Posted by abraxalito View Post
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.
2 wires in a loop give us a common mode choke, right?

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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Last edited by Wavebourn; 27th July 2012 at 03:40 AM.
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Old 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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Old 27th July 2012, 03:42 AM   #25006
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Anyone tried measuring, what a concept?
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Old 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 ball-park.
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Old 27th July 2012, 03:46 AM   #25008
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Bet Kawasaki Ninja ZX-14R has more.
And smaller mean time between fatalities. MTBF
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Old 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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Old 27th July 2012, 03:55 AM   #25010
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And smaller mean time between fatalities. MTBF
I was thinking 'mean free path or time between collisions' myself - MTBC.
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