Re: Does a MOV shunt current or equalize voltage?

John Doe wrote:

From reading intelligent replies to w_tom, I have the impression
that a MOV effectively clamps the input and output together so that
there is no potential and therefore no current through the protected
device. Is that correct?

There is an often repeated idea that a MOV shunts current to ground
and that protects the device. Of course the current might be extreme
since the move acts like a short, but is that really what protects
the circuit? If shunting current is the protective action, doesn't
that mean the transient would have to be more than transient? The
transient high voltage goes away whether current is shunted or not,
doesn't it?

Or is it a combination of both?

Thanks.



MOV's work like zeners but not with the same response range of
clamping..
They have a non-linear effect in it's clamp and they do not act
like a thyristor to create a crow bar effect either.

They can handle a lot more than a conventional zener does how ever, due to their design the life cycle of these units are limited when getting hit hard enough to perform a heavy clamp even if the clamp
fulls with in it's spec.


http://webpages.charter.net/jamie_5";

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