Current sensor problem?

Hi Guys!

I'm struggling again with current measurement...

I bought ACS758LCB-100U sensor few weeks ago and finaly it arrived. It's just sensor, without board, i soldered connectors onto the legs, connectd sensor to 5V supply on Arduino, added 0.1Uf cap between 5v and GND... This sensor type is unidirectional and it has offset of 0.550 Vots with 0A current, but when i apply current through it Vout is decreasing instead increasing!? why is that? i tried to swap polarities of load but then nothing happens, it stays on 0.550V...

Help please!

Regards!

Please supply a full circuit diagram.

Weedpharma

I suppose you understand that this sensor only changes ~8 values per Amp from a "zero Amp" value of ~112. And that a uni-directional sensor is for measuring DC. Not AC. Leo..

Yes i know that, but i don't see why reading changes in oposite direction (vout on sensor decreasing with applying current through the sensor) i'm measuring DC current, not AC.

Circuit:

|500x249

Regards!

How much current.
You will need a few amps to see significant change.
Maybe the sensor has some offset to overcome.
I assume there is no magnet nearby.
Leo…

Wawa: How much current. You will need a few amps to see significant change. Maybe the sensor has some offset to overcome. I assume there is no magnet nearby. Leo..

I tried 1-6 Amp range. No, there is no magnet nearby.

D.

Did you try to measure the output voltage from the sensor with a DMM. Without current it, should be something like 0.5 - 0.6volt (0.55volt mentioned in post#0). With 5A current (the right direction), it should be ~0.2volt more. If not, there must be something wrong with the sensor. Leo..

Wawa: Did you try to measure the output voltage from the sensor with a DMM. Without current it, should be something like 0.5 - 0.6volt (0.55volt mentioned in post#0). With 5A current (the right direction), it should be ~0.2volt more. If not, there must be something wrong with the sensor. Leo..

Yes, i'm doing that all the time with DMM. Exactly, it's something like 0.5-0.6 I will try once again to swap connections between the sensor and the load tomorrow, if it doesnt helps i assume the sensor is faulty.

Thanks for the help!

D.

Here's a trick (that can melt things!).

A (rechargeable) AA battery, clipped to the current terminals of the sensor with thin-ish test leads, provides enough current (2-10A) to test your sensor. Don't do connect for more than 10 seconds. Leo..

Hello!

I tried everything You suggested but with no luck... now it doesn't move from 0.5 volts anymore, probably it was bad sensor from the begining, i will order another piece and try it out!

Thanks for the help to all of You!

D.