Copper foil versus wire in inductors

[Coolin]

Oops thats right...

Well how about measuring anyway but you have to do cut the foil in half first

but seriously what if you measured two short pieces against each other and multiplied this with the approximate length of the coil?

Looking at your graphs the phase lead reduced after removing the cap as well though, unless i'm looking at it the wrong way..

[soongsc]

Originally posted by Coolin
Oops thats right...

Well how about measuring anyway but you have to do cut the foil in half first

but seriously what if you measured two short pieces against each other and multiplied this with the approximate length of the coil?

Looking at your graphs the phase lead reduced after removing the cap as well though, unless i'm looking at it the wrong way..

I'm not really sure how capacitance has to do with this, but it might be interaction between the wires and how they are layed out differently.

Yes, the phase lead was reduced after removing the cap. But it seems there are more complicated things involved.

[kea]

No offense, but I think this is an error of thought. The wire being parallel in all the turns does actually mean that they produce a capacitance. This capacitance of course does not work like a capacitor: this means the capacitor is not in series but in parallel (if you wish). But however you imagine it does not matter, what matters is what you measure! So if it has any effect on the phase or frequency response, then you must be able to measure this! If you cannot measure a phaseshift, then there is no noticable phase shift!
That does not mean however that there is no noticeable difference. Usually one uses sinewaves or pink noise to measure but this does not measure any impuls responses or shifts or distortion. It is therefor important to measure with signals that have more a nature like music (impulses, multiple frequencies simultaneously etc). There is actually such a signal, which a German measurement equipment manufacturer uses. Quite ingenius really.

[soongsc]

If one tries to model a foil inductor in very small increments, it certainly does seem there is a parallel capacitance. How interesting.

I wonder whether anyone has used the wire inductors from Duelund Coherent Audio? It certainly looks interesting, and possibly minimizes magnetic field influence on components nearby.