Post by thread:[EE] DC current sensing with hall effect sensor

I need to measure, then A/D convert into something a PIC can use, DC currents from 1A to 100A. I was told this should be feasible with hall effect sensors, but the application notes I see in freescale and others are apparently more orientated to detect movement of magnetic elements, for instance to work as a tachometer. Does anyone has experience using hall effect sensor for DC current measure? Any application note you know? -- Ariel Rocholl Madrid, Spain

Try this data for Hall Effect UGN3503 device. Has some examples. http://www1.jaycar.com.au/products_uploaded/ZD1902.pdf Peter Ariel Rocholl wrote: >I need to measure, then A/D convert into something a PIC can use, DC >currents from 1A to 100A. I was told this should be feasible with hall >effect sensors, but the application notes I see in freescale and others are >apparently more orientated to detect movement of magnetic elements, for >instance to work as a tachometer. >Does anyone has experience using hall effect sensor for DC current measure? >Any application note you know? > > >

> I need to measure, then A/D convert into something a PIC can use, DC > currents from 1A to 100A. I was told this should be feasible with hall > effect sensors, but the application notes I see in freescale and others > are > apparently more orientated to detect movement of magnetic elements, for > instance to work as a tachometer. > Does anyone has experience using hall effect sensor for DC current > measure? > Any application note you know? > > -- > Ariel Rocholl > Madrid, Spain See http://www.allegromicro.com/hall/currentsensor.asp for Hall effect current sensors. Harold -- FCC Rules Updated Daily at http://www.hallikainen.com - Advertising opportunities available!

Ariel Rocholl wrote: > I need to measure, then A/D convert into something a PIC can use, DC > currents from 1A to 100A. I was told this should be feasible with hall > effect sensors, but the application notes I see in freescale and others are > apparently more orientated to detect movement of magnetic elements, for > instance to work as a tachometer. > Does anyone has experience using hall effect sensor for DC current measure? > Any application note you know? > Check out Allegro ACS755LCB-100-PFF (DIGIKEY 620-1111-ND). It's a 100 Amp sensor based on a Hall effect device.

Check out the NVE GMR magnetic sensors - not hall effect but can be used to measure current. I think they have examples on their website of using them for current measurement We used to use a Honeywell part but I think it is now obsolete. Two main things to watch when using magnetic sensors to measure current - core saturation and remenance. Core saturation will cause non-linearity at the higher current levels unless a lot of "iron" is used - and then the sensitivity drops. Remenence will reduce accuracy as previous history will effect the present reading.(Especially if the current is bi-directional) In order to counter both effects, one method is to use the output of the sensor to control a current drive though a coil to cancel the measured field. The measured current is then simply the canceling current multiplied by the number of turns in the cancelling coil. (But for 100A and 1000 turns you still need 100mA coil current - and if this is provided by a SMPS then it may induce noise on the measured current). Google for "flux-gate" to see another method. Richard P On 19/10/06, Marcel duchamp <spam_OUTmarcel.duchampTakeThisOuTsbcglobal.net> wrote: {Quote hidden}> Ariel Rocholl wrote: > > I need to measure, then A/D convert into something a PIC can use, DC > > currents from 1A to 100A. I was told this should be feasible with hall > > effect sensors, but the application notes I see in freescale and others are > > apparently more orientated to detect movement of magnetic elements, for > > instance to work as a tachometer. > > Does anyone has experience using hall effect sensor for DC current measure? > > Any application note you know? > > > > Check out Allegro ACS755LCB-100-PFF (DIGIKEY 620-1111-ND). It's a 100 > Amp sensor based on a Hall effect device. > > -

Thank you all, I have what I need with all these info. Allegro and NVE GMR devices look good for this and found a nice app note on their website. Appreciate the help. 2006/10/18, Richard Prosser <.....rhprosserKILLspam@spam@gmail.com>: {Quote hidden}> > Check out the NVE GMR magnetic sensors - not hall effect but can be > used to measure current. I think they have examples on their website > of using them for current measurement > > We used to use a Honeywell part but I think it is now obsolete. > > Two main things to watch when using magnetic sensors to measure > current - core saturation and remenance. Core saturation will cause > non-linearity at the higher current levels unless a lot of "iron" is > used - and then the sensitivity drops. Remenence will reduce accuracy > as previous history will effect the present reading.(Especially if the > current is bi-directional) In order to counter both effects, one > method is to use the output of the sensor to control a current drive > though a coil to cancel the measured field. The measured current is > then simply the canceling current multiplied by the number of turns in > the cancelling coil. (But for 100A and 1000 turns you still need 100mA > coil current - and if this is provided by a SMPS then it may induce > noise on the measured current). > > Google for "flux-gate" to see another method. > > Richard P > > On 19/10/06, Marcel duchamp <marcel.duchampKILLspamsbcglobal.net> wrote: > > Ariel Rocholl wrote: > > > I need to measure, then A/D convert into something a PIC can use, DC > > > currents from 1A to 100A. I was told this should be feasible with hall > > > effect sensors, but the application notes I see in freescale and > others are > > > apparently more orientated to detect movement of magnetic elements, > for > > > instance to work as a tachometer. > > > Does anyone has experience using hall effect sensor for DC current > measure? > > > Any application note you know? > > > > > > > Check out Allegro ACS755LCB-100-PFF (DIGIKEY 620-1111-ND). It's a 100 > > Amp sensor based on a Hall effect device. > > > > --

Hi Ariel, I´m using hall current sensors from Allegro (ACSxxx). They have some parts for +- 100A, output linear 0-5v from -100A to 100A (0A = 2,5V). Easy to use with a PIC AD. good luyck! Rubens At 13:47 18/10/2006, you wrote: {Quote hidden}>I need to measure, then A/D convert into something a PIC can use, DC >currents from 1A to 100A. I was told this should be feasible with hall >effect sensors, but the application notes I see in freescale and others are >apparently more orientated to detect movement of magnetic elements, for >instance to work as a tachometer. >Does anyone has experience using hall effect sensor for DC current measure? >Any application note you know? > >-- >Ariel Rocholl >Madrid, Spain >

Allegro will send you free samples if you ask. On 10/18/06, rlistas <.....rlistasKILLspam.....gmail.com> wrote: {Quote hidden}> > Hi Ariel, > > I´m using hall current sensors from Allegro > (ACSxxx). They have some parts > for +- 100A, output linear 0-5v from > -100A to 100A (0A = 2,5V). > Easy to use with a PIC AD. > > good luyck! > > Rubens > > At 13:47 18/10/2006, you wrote: > >I need to measure, then A/D convert into something a PIC can use, DC > >currents from 1A to 100A. I was told this should be feasible with hall > >effect sensors, but the application notes I see in freescale and others > are > >apparently more orientated to detect movement of magnetic elements, for > >instance to work as a tachometer. > >Does anyone has experience using hall effect sensor for DC current > measure? > >Any application note you know? > > > >-- > >Ariel Rocholl > >Madrid, Spain > >-