MJLorton Solar Power and Electronic Measurement Equipment Forum

New topics, ideas, reviews for the video blog => New topics, ideas, reviews for the video blog => Topic started by: Tooms on July 01, 2012, 02:56:03 AM

Title: T4D #14 - DMM Ref Check giveaway, Lascar Graphic Panel Meter...and more news..
Post by: Tooms on July 01, 2012, 02:56:03 AM

http://www.youtube.com/watch?v=HBWibhYqx3c&feature=plcp
Title: Re: T4D #14 - DMM Ref Check giveaway, Lascar Graphic Panel Meter...and more news..
Post by: Tooms on July 01, 2012, 02:56:24 AM

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
Title: Re: T4D #14 - DMM Ref Check giveaway, Lascar Graphic Panel Meter...and more news..
Post by: Fennec on July 01, 2012, 06:19:07 PM
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.
Title: Re: T4D #14 - DMM Ref Check giveaway, Lascar Graphic Panel Meter...and more news..
Post by: MJLorton on July 02, 2012, 06:40:11 AM

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.
Title: Re: T4D #14 - DMM Ref Check giveaway, Lascar Graphic Panel Meter...and more news..
Post by: Tooms on July 02, 2012, 11:06:49 AM

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