Re: Meter Shunts ??

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: <tesla@xxxxxxxxxxxxxxxxxxx>

A meter shunt is really just a big low resistance resistor.

The idea is you can measure a large curent by measuring the voltage drop
across the shunt. Say you have a 400amp shunt rated 50mV. All it does is
have a voltage drop of 50mV when you run 400amps though it. 200amps across
it will make 25mV. they low voltages they output are great for direct
attachment to most analog meters.

Shunts are for measuring current, not voltage in a circuit, even though
they work be measuring a small voltage and presenting it on a meter with
current on the legend.

Shunts don't drop any current, but will drop the same amount of voltage
across them as the meter reads. Again, this tends to be tens of mV at
most.

Meter shunts are not isolated from the load you are measuring. If you are
working with high voltages that float above ground, this will be present
in the meter too, so you need to watch out for that.

KEN



On Sun, 13 Feb 2005, Tesla list wrote:

> Original poster: Thomas DeGregorio <tommacs@xxxxxxxxxxxxx>
>
> Hi I'm so confused about meter shunts. I need one for a high current
> application but I think it would be good to use with my TC too. Oh it's for
> my surge generator. I never used a shunt before and to me it seems that
> shunts drop the current but not the voltage, is this true? I can't seem to
> figure it out. Yeah really do know where else to ask this question so I
> figured I'll just pop a quick one :)
>
> Thanks for your help,
> Tom
>
>
>