Hall Effect current measurement?

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Hall Effect current measurement?

Post by ian » Wed Oct 08, 2003 7:50 pm

Ya think its possible to measure DC current in a wire using a linear hall effect sensor? Anybody ever tried this?

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Re: Hall Effect current measurement?

Post by bodgy » Wed Oct 08, 2003 8:49 pm

yes!<p>Silicon Chip the only remaining Australian magazine had just such a project a couple of months ago.<p>What you need is a either a toroid core cut in half with the sensor in between the join some turns of copper wire (this will depend on the current you want to measure and the max voltage you want at the measuring end)<p>Or<p>You can purchase one of those interferance type toroids the type that clip on to your mains lead for noise prevention, same set up as above.<p>Colin
On a clear disk you can seek forever.

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Re: Hall Effect current measurement?

Post by rshayes » Wed Oct 08, 2003 8:55 pm

Yes you can. Tektronix sold a current probe for oscilloscopes that had response down to DC. Actually, it used two pickups. High frequencies were picked up by a current transformer. Low frequencies and DC were sensed by using a Hall effect device. The two signals were combined together to get a bandwidth from DC to about 50 MHz.<p>The hall effect device was used to sense zero field. It generated an error signal which was amplified and used to cancel the flux from the current being measured. This probably gave better linearity and dynamic range.<p>Fluke may have also made a Hall effect probe for digital multimeters. I have a vague memory of some advertisements for this, but nothing definite.<p>Hewlett-Packard sold a current meter in the 1960's that used a form of flux gate device to measure DC currents. This is an alternative to the Hall effect device.

Chris Foley
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Re: Hall Effect current measurement?

Post by Chris Foley » Wed Oct 08, 2003 10:03 pm

Allegro makes a line of Hall effect current sensors which are good at measuring both DC and AC currents, with a bandwidth well into the audio range. They work, they're easy to use, and they're less than $10.00 USD each in single quantity from Newark. They have current sensors which have 50, 75 and 100 amp full scale output. You will have to break the line, and either solder or clamp the two ends to the sensor. They operate on 5VDC, and provide a DC output voltage proportional to the current.<p>The parts are called ACS750SCA-050, ACS750SCA-075 and ACS750SCA-100.<p>ACS750SCA-050 data sheet.pdf<p>These are easy and straightforward, and more than good enough for all but the most accurate setups.<p>Good luck.
Chris<p>[ October 08, 2003: Message edited by: Chris Foley ]</p>

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