Re: surface area of wire

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

Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com>

Hi Chris,

See Gary's excellent work at:

http://www.laushaus-dot-com/tesla/primary_resistance.htm

Cheers,

         Terry

At 07:11 PM 9/18/2003 +0100, you wrote:
>Hi all,
>
>I'm considering winding a small test coil with litz wire. I would like to
>know if theres a chart which states the skin depth of wire at high frequency
>in mm. Ive seen a chart in inches floating around though I can only get to
>grips with mm. From what ive found 200khz is around 0.15mm skin depth. It
>would be useful to have exact figures.
>
>Also, Is there any comparrisons to surface area in relation to solid
>core,multistrand and litz wire ? For example if I have a wire of 1mm dia,
>surface area would say be 3mm, now if I had a 1mm Dia wire with multistrand
>how would that be worked out ? All the wires are shorintg out in all
>combinations so in comparrison to the solid core wire I wouldn't imagine
>multistrand to give much more surface area than solid core ?
>
>Litz wire would be the best. I plan to build a high Q secondary with this
>wire to see what happens. I have compaired solid core to stranded wire and
>was amazed to find the multistrand coil gave 2" arcs with little input
>power, though a solid wire which should have been better , wasn't and gave
>no output at all. Despite the stranded wire had spaced turns ( due to
>insualtion ) there should be a lot less output since the solid core verson
>was a normal wound secondary. Length of wire and wire dia was as close as I
>could get.
>
>I think it would make a interesting test since multistrand worked better
>than solid wire. which is why im interested in testing out Litz wire which
>would give me 10times the surface area and should give a much higher Q coil.
>
>Many thanks,
>Chris