Anyone measuring mains current with a 3 pin SMT Hall effect sensor? - Page 1
Forum section: electronics / projects

author: Jester
author_rank: Frequent Contributor
timestamp: March 05, 2023, 08:52:44 am
content: I'm looking for a small, PCB mountable sensor (0-30A ac 60Hz) really low cost, isolated (120V mains). Accuracy is not very important 1A resolution would be acceptable. Low current consumption (< 10ma) would be ideal. The readily available CT's are too large, and many of the analog sensors have limited isolation (100V typical). I will sample the output with an A/D.Using something like this is appealing if it can work:https://www.digikey.ca/en/products/detail/texas-instruments/DRV5053OAQDBZR/5015736Using the PCB as the isolation barrier appeals to me and the power consumption is also less than the part below. Sensitivity might be marginal, If I assume 0.1mT per amp based on 60mil board and the 45mv/mT sensor, thats only 4.5mV per amp. That seems a bit small when considering stray magnetic fields, electrical noise etc.This (other than the current consumption) looks like it would work:https://www.digikey.ca/en/products/detail/monolithic-power-systems-inc/MCS1802GS-30-Z/14115502?s=N4IgjCBcoKwExVAYygMwIYBsDOBTANCAPZQDaIAzGAJwDsYCAuoQA4AuUIAymwE4CWAOwDmIAL6EAbNUQgUkDDgLEyIACwAGahW0hmIdpx4CR4wmA21Js%2BYryESkchUsUKTVh0jc%2BQ0RPAwGAobNCx7FScQOBiNPU8jX1MAhmoIaDkwpQdVOGo1ajhrQjyCsAAOeIMvHxN-QgBaBAz5PgBXZUdyGBBCGUYxAObyAAksTAACXFRUXCQ2CbxBbCJeCb0xIA

author: Terry Bites
author_rank: Super Contributor
timestamp: March 05, 2023, 09:38:44 am
content: You could do that.If its just for a few off, you can buy ACS712 current sensor modules for less than a half a pint of beer.

author: mawyatt
author_rank: Super Contributor
timestamp: March 05, 2023, 04:18:42 pm
content: Awhile back we needed a means to monitor precision stepper motor winding currents as well as the winding differential voltages. This was to monitor the parameters of various stepper controllers including micro-stepping (discovered some really bad controllers, but that's another story).We didn't have a pair of isolated current probes so designed a DIY approach and used the Allegro ACS724 Hall Effect Isolated Current Sensor shown below. These worked very well in our application.https://datasheet.lcsc.com/lcsc/1811151657_Allegro-MicroSystems--LLC-ACS724LLCTR-10AB-T_C99740.pdfAnyway, hopefully this is useful.Best,

author: MathWizard
author_rank: Super Contributor
timestamp: March 06, 2023, 08:07:11 am
content: I bought 20 cheap Hall effect sensors. I never tried them and IDK their part ATM, but in general, whats possible with a jelly bean HES ? Could you sense mains current from a dryer at few feet ? Or find live wires in your walls ?I have a ton of little projects I could make, including with Arduino. Maybe I should try my HES. But I've been trying to repair some un-repaired junk pile.

author: LukeW
author_rank: Frequent Contributor
timestamp: March 06, 2023, 02:57:33 pm
content: I think you need some magnetic or ferrite element to collect the magnetic flux and funnel it into the Hall sensor.Like Honeywell CSLT series, which has the toroid surrounding the Hall sensor.https://sps.honeywell.com/au/en/products/advanced-sensing-technologies/aero-and-transportation-sensing/aero-and-transportation-sensors/current-sensors/open-loop-current-sensors/cslt-series

author: Infraviolet
author_rank: Super Contributor
timestamp: March 06, 2023, 07:04:14 pm
content: Diodes Inc AH49 hall sensor? You'll want one with a linear output, and depending on the B field strength from the current carrying wires you can pick how sensitive a model you want.