Re: Amp Meter

From: Nikki (rickj_at_sympatico.ca)
Date: 02/18/05 

Date: Thu, 17 Feb 2005 20:16:26 -0500

Guys thanks for all your replies
I took the suggestion of Rich and found that with a 1.5volt battery and a
resistance of 10400 ohms I can get the meter to read at its last increment.
The meter is marked in increments of 10 up to 60 how would I get a 2 amp
draw to read 20 where a 6 amp draw would be the last increment on the meter
Thanks
Nikki
"Jamie" <jamie_5_not_valid_after_5_Please@charter.net> wrote in message
news:PQIQd.11468$l33.11037@fe06.lga...
> Nikki wrote:
>
> > On closer inspection of the meter I have taken the cover off and the
needle
> > will not move so I think the meter is no good. I have a second I would
like
> > to use this one goes from 0 to 60 On the back it has a + on one of the
posts
> > and printed on the back is 120 on the front of the meter is says (its
very
> > small print) FS-50mvDC and it also says D C Amperes. Now I know this
came
> > from the Phone company and it was on a 48 volt circuit.
> > Nikki
> > "Rich Grise" <rich@example.net> wrote in message
> > news:pan.2005.02.15.18.55.11.112456@example.net...
> >
> you will need to determine the coil R (resistance), 120 maybe it.
> lets assume for the moment that it is.
> your scale is 0..60, we will use that for amp scale.
>
> Imeter = 0.050/120 = 416 uA ( does not seem likely etc).
>
> Rshunt = 0.050/(60.0 - 0.000416) = 0.00083 ohms
>
> so this would mean you need a shunt resistor on the
> meter terminals of 0.00083 which is more like a bar
> of copper across the terminals of the meter.
> if the 120 number you are reading is actually indicating
> I of the meter then you use 120 uA or 120 mA instead of the
> 416 uA in the first calculation.
>
> in either case, you will need to refer to a wire&meteral
> chart to get teh ohms per 1K' (per 1k feet) to determine what
> you need to create a shunt .
>
> these are only my thoughts off the top of my head going by the
> info your passing.
>
>
>
>

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