how to set up shunt

[windrules]

Hi guys, have been reading up on measuring amps using a length of wire for a shunt to measure amps but are not sure where one is supposed to put meter to get reading.Has someone got a diagram out there to show how this is done.

thanks,

Mos

[wpowokal]

Try this link.

http://www.uoguelph.ca/~antoon/gadgets/shunts/shunts.html

regards Allan

[TomW]

Allan;

Pretty good link. Not only lays out the math but has diagrams for those that can't visualize the text description.

I have been using several #10 copper wire shunts here for a long time and find them to be perfect for use with those junkbox meters a packrat like myself tends to collect.

Cheers.

TomW

[stop4stuff]

Hi,

Another link...

'How to make your own multimeter'

http://www.allaboutcircuits.com/vol_6/chpt_3/11.html

Schematics, diagrams and illustrations and helpful understanding of why it works

paul

[Ungrounded Lightning Rod]

I'd do one thing a tad differently than the posted article:

I'd make the shunt out of house wire, which is already bare.  And I'd put my meter taps on it by using a grounding block from a breaker box (available as add-ins for cheap at your local hardware store's electrical asile).

These blocks have a series of holes, with screws, to clamp protective ground wires (plus a couple holes for mounting them in the breaker box.)

Cut off a couple pieces with two hole/screw pairs each.  Thread them onto your wire, and thread your meter wires into the other holes and clamp 'em down.  Now you can readjust them as necessary and clamp them on during calibration.

Note:  NEVER connect the meter AT OR BEYOND a junction between the shunt and the rest of the wiring.  The resistance of the connection of the shunt to the wiring will be a large fraction of the shunt's resistance and will vary with temperature.  (And if it ever comes lose you end up with the entire supply voltage across your meter and the entire load current through it.  This smokes mechanical meters and may damage, or blow the fuse on, even electronic testers.)

[windrules]

Thanks guys that's exactly what I wanted to know and a good link thanks Allan.Sometimes I find it dam hard to search out exactly what you are after.

Thanks again,

Mos