RE: "New Inductance Formula"

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "David Thomson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <dave-at-volantis-dot-org>

Hi Alex,

>the conductance quoted (2.112E-4 siemens(mhos in modern units)

Actually mhos is the old unit and siemens is the new unit.

http://www.glossary.oilfield.slb-dot-com/Display.cfm?Term=conductance

2.  n.  [Geophysics] The reciprocal of resistance in a direct current
circuit, measured in siemens (formerly mhos). In an alternating current
circuit, conductance is the resistance divided by the square of impedance,
also measured in siemens.

>is equal to a resistance of about 4700 ohms (per what unit i have no idea -
conductance is a property of a discrete object rather than a 'substance'
such as the 'aether' [sic - ether])

This can be proven mathematically as derived from Coulomb's constant.  We
can talk about this off list if you would like.

>this is held out by the experiemntal observation that it appers to be out
by a factor of about 500 where as Wheeler gets you to within less than 1%.

It comes in far closer than a factor of 500.  Did you use wire length as
opposed to winding length?

Give the formula a try with one of your own coils and see how far off it is.

I used this formula for tuning my Tesla magnifier coil (combination flat
spiral and solenoid secondary) and it was right on the money in predicting
the tuning point of the primary.

Dave