Re: Why tesla coil is air-cored to operate efficiently at high freq?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Antonio Carlos M. de Queiroz" <acmdq@xxxxxxxxxx>

Tesla list wrote:
> Original poster: d a <btoc3000@xxxxxxxxxxxx>
> I have three theoretical questions here:
> I read this from a website: "A normal transformer users an iron core 
> in order to operate at low frequencies, whereas the Tesla Coil is 
> air-cored to operate efficiently at much higher frequencies".
> I understand that a normal transformer relies on turn ratios and the 
> air core is there to reinforce the magnetic flux.
> May I then ask, why is an iron core only required in low frequency 
> operation and why do we use an air-core for high frequency operation?

A core in a Tesla coil would increase coupling and result in too few
turns in the primary coil, if the inductances are kept. Would also be
a serious insulation problem. In high-frequency operation, cores are
not used because they are not necessary.

> Lastly, I read this from another website: " In the Tesla "swing", 
> the kick is supplied by the AC electrical current moving back and 
> forth". Can someone elaborate on this please? Is it actually 
> referring to the LC circuit - both the secondary and primary 
> operating at the same frequency that reinforce each other?

Possibly. One of these texts that mention a thing called "inductive
kick", that approximates the actual behavior of an induction coil, and
has no relation with the operation of a Tesla coil.

Antonio Carlos M. de Queiroz