Author Topic: T4D #14 - DMM Ref Check giveaway, Lascar Graphic Panel Meter...and more news..  (Read 3211 times)


Tooms

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Hi

you can also build your own power shunt, i have just done this http://www.tooms.dk/Tblog/Showblog1.asp?BlogID=201205271840516179

I found some very good resistors on ebay and then mount then on an heat shink.

Thomas

Fennec

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If you have a high quality Ohm range meter, you can use simple a piece of copper, like electric installation cable.

http://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity

And it's pretty easy to calculate.

Maybe you want measure 40A in a mV range.

length = (resistance * profile) / resistivity
(0,001 Ohm * 1,5mm2) / 0,0175 Ohm =  8,57 cm

0,001Ω * 40A =  40mV

If you need a higher range, make it longer or use Aluminium, Steel, Constantan or something like that. The most effort is the adjustment.
And you don't need such a big heat sink. For sure, don't forget the thickness, the demand ot the profile and the temperature coefficient.

MJLorton

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Hi

you can also build your own power shunt, i have just done this http://www.tooms.dk/Tblog/Showblog1.asp?BlogID=201205271840516179

I found some very good resistors on ebay and then mount then on an heat shink.

Thomas

Great project Thomas, thanks for posting. You have far too many "toys"! ;-)

I'll contact you about LAN access to the 8846A as soon as time allows.

Cheers,
Martin.
Play, discover, learn and enjoy! (and don't be scared to make mistakes along the way!)

Tooms

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Hi


yes it is an nice shunt and i have already used it an number of times


Just let know if i can help with the LAN access on the 8846A but i dont understand why it is not working on yours.
Maybe a phone call to fluke support can be an good idea so they can tell what is wrong and make sure that there is not anything wrong with the meter.


Thomas