hall censor to measure current

[Prototyp_V1.0]

Hi.

I'm thinking about building a simple PMW scurrent source. Disregarding the frequenzy, would a hall censor be a god choice to measure current?

I'm thinking this because a high current output measurement will cause a reasonable loss of wattage because the neccesary resistor.

 

[stube40]

Its certainly an easy way to measure the current in an non-intrusive way.

You can make your job a whole lot easier if you get one of the packages that have the hall sensor pre-moulded in place and calibrated, hence you just plug and go.

For instance, I'm currently designing a circuit using the Allegro ACS758 - this is no doubt overkill for your application as it can handle up to 200A, but it's a good example of an off the shelf solution that is fuss free.

 

[Prototyp_V1.0]

Thanks stube

I guess I also van use one that I've pilled out from brushless DC motor. Gain isn't important because I can always adjust that with an extra amplifier.

Btw: what's the price in Europe for such a ACS758? (most expensive vs. cheapest model). I couldn't find it on the manufactors web page.

 

[karesz]

Hi,
Check pls at Farnell...
K.

Added after 2 minutes:

..//no.farnell.com Kr 75.,-

 

[samppa]

Hi,

If 30 Amps is enough, let me recommend Allegro's ACS712, which goes for about 2 EUR/pcs at 100+ quantities. I have used it in a couple of projects and it really is a good performer for the price, which is less than the price of similar ready-to-use current tranformers that I have found. Also it is more compact and easy to assembe as a SMD soic8 package.

With hall effect sensor you must remember that all magnetic fields interfere with the measurement. Don't put any other high current traces or wires near the sensor, and if you want the best possible performance, you may need to filter out the effect of earth's magnetic athmosphere.

-Samppa