P E Schoen wrote...> > You might also consider an analog Hall effect sensor > you can glue to a PCB over a track. Less than a dollar: >http://www.mouser.com/ProductDetail/Texas-Instruments/DRV5053EAQLPGMAn elegant idea, Paul. But the 20kHz bandwidth is lacking. A current transformer does better than that and is also isolated. -- Thanks, - Win
current monitor
Started by ●September 27, 2016
Reply by ●September 30, 20162016-09-30
Reply by ●October 1, 20162016-10-01
On 30 Sep 2016 18:53:27 -0700, Winfield Hill <hill@rowland.harvard.edu> wrote:> An elegant idea, Paul. But the 20kHz bandwidth > is lacking. A current transformer does better > than that and is also isolated.I strongly suggest you take the advice of someone else in this thread and take a look at the Allegro hall effect sensors. Here's the one I use in my induction heaters. http://www.digikey.com/product-detail/en/allegro-microsystems-llc/ACS758ECB-200B-PFF-T/620-1323-ND/2042748 I replaced a shunt and an CT. It allowed me to correctly high side sense for my buck converter power controller. with a 150kHz bandwidth, it also showed me some stuff that the CT rolled off that was important to the reliability of the units. John John DeArmond http://www.neon-john.com http://www.tnduction.com Tellico Plains, Occupied TN See website for email address
Reply by ●October 1, 20162016-10-01
On 9/30/2016 9:53 PM, Winfield Hill wrote:> P E Schoen wrote... >> >> You might also consider an analog Hall effect sensor >> you can glue to a PCB over a track. Less than a dollar: >> http://www.mouser.com/ProductDetail/Texas-Instruments/DRV5053EAQLPGM > > An elegant idea, Paul. But the 20kHz bandwidth > is lacking. A current transformer does better > than that and is also isolated.I think whether 20 kHz is limiting depends on your application. Transformers tend to be rather large compared to a TO-92. -- Rick C
Reply by ●October 1, 20162016-10-01
Neon John wrote...> >On 30 Sep 2016 18:53:27 -0700, Winfield Hill ><hill@rowland.harvard.edu> wrote: > >> An elegant idea, Paul. But the 20kHz bandwidth >> is lacking. A current transformer does better >> than that and is also isolated. > > I strongly suggest you take the advice of someone > else in this thread and take a look at the Allegro > hall effect sensors. Here's the one I use in my > induction heaters. allegro-microsystems ACS758Thanks, John, I missed seeing that. I like the serious look of the package, but I'm puzzled why they don't offer one with leads prebent for SMT. The 50A lowest FS range is an issue, with a 100mA DC offset. But I guess many apps can figure out their own specific offset. -- Thanks, - Win
Reply by ●October 2, 20162016-10-02
"rickman" wrote in message news:nsoheo$u7k$1@dont-email.me...> On 9/30/2016 9:53 PM, Winfield Hill wrote: >> P E Schoen wrote... >> >>> You might also consider an analog Hall effect sensor you can glue to a >>> PCB over a track. Less than a dollar: >>> http://www.mouser.com/ProductDetail/Texas-Instruments/DRV5053EAQLPGM > >> An elegant idea, Paul. But the 20kHz bandwidth is lacking. A current >> transformer does better than that and is also isolated.> I think whether 20 kHz is limiting depends on your application. > Transformers tend to be rather large compared to a TO-92.Also transformers require a break in the track on the PCB. Here's one good to 40 kHz: http://www.mouser.com/ds/2/187/honeywell-sensing-ss39et-ss49e-ss59et-datasheet-00-947415.pdf And another but only 10 kHz: http://www.mouser.com/ds/2/115/AH49E-271509.pdf These are probably the same sort of device as used in the transformer type: http://sensing.honeywell.com/honeywell-sensing-cslt-series-product-sheet-005862-2-en.pdf However that unit has 3 uSec typical response. Paul
Reply by ●October 2, 20162016-10-02
On Saturday, October 1, 2016 at 6:13:30 PM UTC+2, Winfield Hill wrote:> Neon John wrote... > > > >On 30 Sep 2016 18:53:27 -0700, Winfield Hill > ><hill@rowland.harvard.edu> wrote: > > > >> An elegant idea, Paul. But the 20kHz bandwidth > >> is lacking. A current transformer does better > >> than that and is also isolated. > > > > I strongly suggest you take the advice of someone > > else in this thread and take a look at the Allegro > > hall effect sensors. Here's the one I use in my > > induction heaters. allegro-microsystems ACS758 > > Thanks, John, I missed seeing that. I like the > serious look of the package, but I'm puzzled why > they don't offer one with leads prebent for SMT. > The 50A lowest FS range is an issue, with a 100mA > DC offset. But I guess many apps can figure out > their own specific offset. >You can get a +/- 40A part in SMD SOIC8. It has 80kHz bandwidth ACS723: http://www.allegromicro.com/~/media/files/datasheets/acs723-datasheet.ashx Cheers Klaus
Reply by ●October 2, 20162016-10-02
On Sunday, 2 October 2016 23:08:17 UTC+2, Klaus Kragelund wrote:> On Saturday, October 1, 2016 at 6:13:30 PM UTC+2, Winfield Hill wrote: > > Neon John wrote... > > > > > >On 30 Sep 2016 18:53:27 -0700, Winfield Hill > > ><hill@rowland.harvard.edu> wrote: > > > > > >> An elegant idea, Paul. But the 20kHz bandwidth > > >> is lacking. A current transformer does better > > >> than that and is also isolated. > > > > > > I strongly suggest you take the advice of someone > > > else in this thread and take a look at the Allegro > > > hall effect sensors. Here's the one I use in my > > > induction heaters. allegro-microsystems ACS758 > > > > Thanks, John, I missed seeing that. I like the > > serious look of the package, but I'm puzzled why > > they don't offer one with leads prebent for SMT. > > The 50A lowest FS range is an issue, with a 100mA > > DC offset. But I guess many apps can figure out > > their own specific offset. > >Normally you would do a offset nulling of the current sensor during power-up or regulary, since it has an offset voltage for 0A anyway Cheers Klaus
