Re: Well, I know what's wrong - My brand new NST fried!!

[Terry Fritz <twftesla-at-uswest-dot-net>]

Hi Garry,

	A MOV is a Metal Oxide Varistor.  It is a two leaded device that acts as
an open circuit until a given voltage is reached.  It then acts as a hard
short above that voltage.  It acts much like a spark gap to protect
electronic circuits in practically everything these days.  In our case, The
big 1800 volt ones can be put in series to add up to a nice clamping level
to protect NSTs from over voltage damage.  MOVs cannot take a heavy load
for long before they overheat and short out permanently, but they can take
very high power hits and such.  They also have the advantage of being very
fast, predictable, and easy to use.  You should still use safety gaps, but
MOVs provide absolute safety when all else fails.

Pictures of my NST filters are at:

http://63.225.104.218/test/TeslaCoils/MyCoils/SmallCoil/small_protection.jpg
http://63.225.104.218/test/TeslaCoils/MyCoils/BigCoil/protection.jpg

The moves are the little black things in a row.

Cheers,

	Terry


At 11:00 PM 8/22/00 -0700, you wrote:
>Thanks for the url for the picture of the filter.
>
>What I was wondering badly was. What is a MOV??
>