Re: skin effect

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

Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

At 07:45 AM 5/7/2003 -0600, you wrote:
>Original poster: "Ryan Molecke by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <ryan-at-molecke-dot-com>
>
>My small coil actually resonates at around 3.3 MHz, does anyone know if this
>would be a high enough frequency to cause the current to run completely over
>the skin?
>
>I have taken the streamers from my coil directly to my hand (without much
>shock sensation), and I have also done this with a coil operating at around
>1.7 MHz, with more shock sensation. Does the amount of current in the
>streamers depend directly on the turns ratio of the coil?
>
>Ryan


First off.. taking RF discharges to your body is bad... the frequency is 
high enough that your nerves don't respond to the electric field (you don't 
get "shocked") so you can get a bad burn that is very deep before the 
thermal effects cause a sensation.

Skin effect goes as the square root of frequency (i.e. 10 times the 
frequency gives you 1/3.16 the skin depth) and is affected by the 
conductivity of the body (higher conductivity means thinner skin depth). 
Using the oft cited 1 meter for things of the conductivity of humans at a 
few hundred kHz, at 3 MHz, the skin depth would be maybe 30 cm... still 
enough that bulk conduction is going to be the dominant mechanism..