Hall effect current sensors  - Page 1
Forum section: electronics / projects

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: April 27, 2016, 11:57:36 pm
content: HelloI am scoping a cheap 20-30A hall effect sensor and so far the ACS712 seems to be the best option.With that said would any of you guys know if there are better alternatives out there?Cheers

author: zlymex
author_rank: Frequent Contributor
timestamp: April 28, 2016, 12:47:47 am
content: It is a very convenient hall effect sensor, but the accuracy is not very good because it depends on the linearity of the hall sensor which is not quite linear.If you require more precision, a close-loop type such as LEM LAH 25-NP can be used with much better improvement on the overall accuracy.http://www.alldatasheet.com/datasheet-pdf/pdf/81525/LEM/LAH25-NP.html

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: April 28, 2016, 01:09:17 am
content: Quote from: zlymex on April 28, 2016, 12:47:47 amThanks should have mentioned that accuracy is not too much of a worry. The sensor you posted definitely seems better but is also x10 the cost, the harsh reality of engineering...

author: Seekonk
author_rank: Super Contributor
timestamp: April 28, 2016, 04:43:40 am
content: I only buy the 5A versions and shunt them for higher current. Does that really look like something to put 30A through?

author: Zeranin
author_rank: Regular Contributor
timestamp: April 28, 2016, 04:51:44 am
content: Yes, I know you said 'cheap', but for the record the best available are the LEM/Danfysik Ultrastab series, that our sprinkled around our physics research labs like confetti. That said, in my experience they are not metrology grade, and the settling time say to within 10ppm is woefully long at around 300 ms, even though the 10-90% rise time is just a few us.

author: zlymex
author_rank: Frequent Contributor
timestamp: April 28, 2016, 05:03:06 am
content: Quote from: Zeranin on April 28, 2016, 04:51:44 amThat's right. I have several Ultrastabs but I didn't test the settling times because I use them on DC. Have you figured it out why? I have re-engineered the schematics but not make good use it. I can put it here if anyone interested.

author: Zeranin
author_rank: Regular Contributor
timestamp: April 28, 2016, 11:36:36 pm
content: Quote from: zlymex on April 28, 2016, 05:03:06 amZylmex, you are amazing. Every time some high-end obscure electronic device is mentioned, you have one! If not too much trouble, then I'm interested to see your reverse-engineered schematics. I never investigated why the Ultrastabls have poor settling time, but did discuss this at great length with the manufacturer, LEM. For a month of discussion they did not believe there was a proble, but finally got to duplicating my own measurements and conceded that my claims of slow settling time were true. They never did discuss the cause though. That said, the Ultrastabs are probably the best available.

author: John Heath
author_rank: Frequent Contributor
timestamp: April 29, 2016, 12:47:42 am
content: Quote from: ANTALIFE on April 27, 2016, 11:57:36 pmYour cell phone has a hall effect sensor for free. I have used my phone to sense DC current in my car for head lights and starter amps. Put a small magnet behind your phone to locate the hall sensor location from max reading then mark with a X. This is your location to place a wire for + or - 15 percent reading. It sucks for AC current but DC current sensing is not bad. For a step up a sperrty model AV-2A is a cheap alternative. It will measure AC and DC current unlike most clamp meters that are limited to AC only. When I say cheap I mean cheap in the full sense of the word. It says true RMS. In small print it say true RMS providing it is a sine wave ,, ha. However it gets the job done.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: April 29, 2016, 01:01:36 am
content: Quote from: ANTALIFE on April 27, 2016, 11:57:36 pmFor what application? The RC world has many current sensors.http://www.hobbyking.com/hobbyking/store/__63451__Current_Sensor_for_OrangeRx_Telemetry_System.html

author: zlymex
author_rank: Frequent Contributor
timestamp: April 30, 2016, 10:49:40 am
content: Quote from: Zeranin on April 28, 2016, 11:36:36 pmHere is it. I also tore apart one.