[Prev][Next][Index][Thread]
Re: Capacitance of a coil
>
>> A further note in this book states that the important parameters in
the coil
>> capacitance are the diameters of the winding and the ratio of the
pitch
>of the
>> winding to the diameter of the bare wire. The capacitance is
practically
>> independent of the number of turns. Of course, the wire insulation
>thickness
>> and dielectric constant and the form on which the coil is wound will
alter
>> the capacitance of the coil.
>> If you try this, Let me know how it works.
>> Mike
>
I agree... I derived some eqns earlier today in an attempt to
approximate a coil by modelling a capacitor with flat toroidal
electrodes. It seemed in my eqns that if the spacing between turns and
thickness of wire rato is held constant, and diameter of coil held
constant (measured from the CENTRE of the wire - ie inside dia + 1
winding thickness) then capacitance per unit length of coil should be
pretty much constant...
If this is actually the case, and as inductance of a coil is prop to
square of no of turns to a fair approximation, then the self resonance
of the coil should be proportional to no of turns, or inversely
proportional to wire thickness !(with length, dia, pitch const.)
______________________________________________________
Get Your Private, Free Email at http://www.hotmail-dot-com