Re: hi freq's and computers

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

Original poster: "Mark Broker by way of Terry Fritz <teslalist-at-qwest-dot-net>" <mbroker-at-thegeekgroup-dot-org>

You're going to have to explain to me why it matters if the PC is 
functioning.  As I see it, all the cords and cables act as antennas.  The 
ICs and other goodies on the "inside" of the computer doesn't care if the 
circuit is powered up or not for the HV, RF "stuff" the "antennas" picked 
up to fry the circuits.

That being said, the only way we were able to kill the CPU at the thon was 
to take the cover off, and start pulling wires above the the case.  The 
fire was *NOT* started by the TC....  After 15 minutes of attempting to 
"fry" it, someone got a little "creative" with some lighter fluid....  We 
theorize that the metal Farady cages that also happen to be the CPU and 
monitor cases shielded all the "stuff" from the electronics.  The keyboard 
died early on, after sustaining many repeated hits to one part of the 
keyboard.  We're still not sure if the K/B itself died or the controller in 
the CPU box fried.

That reminds me - we gotta find something "interesting" to do for our thon 
finale in 8 days....  anyone have any suggestions?  "Destroying things for 
the benefit of science" is preferred, but anything "cool and interesting" 
will do.

Cheers,

Mark Broker
Chief Engineer, The Geek Group

On Fri, 25 Jul 2003 05:42:44 -0600, Tesla list <tesla-at-pupman-dot-com> wrote:

>Original poster: "Mike Harrison by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <mike-at-whitewing.co.uk>
>
>On Thu, 24 Jul 2003 17:52:19 -0600, you wrote:
>
> >Original poster: "Bernie Crews by way of Terry Fritz 
> <teslalist-at-qwest-dot-net>" <bern-at-flaccess-dot-com>
> >
> >Is it dangerous to have your computer in the same room as your experiments?
> >Does anyone know how far away do we need to keep our computers from a Tesla
> >coil?
> >
> >Thanks for the info.
> >
>The risk of damage is hugely reduced if the computer (or other 
>electronics) is switched off (in the
>case of ATX supplies and other things with 'soft' mains switching, also 
>unplugged).
>This is because when switched on, it takes a much smaller amount of 
>coupled energy to cause damage,
>as the energy can cause latchup in semiconductor devices, then the 
>device's power supply provides
>the power to do the actual damage.
>
>Disregarding extreme cases like direct strikes, the damage threshold of a 
>switched-off devices will
>be several orders of magnitude higher than one that is switched on.
>