Arduino Current Sensor Problem

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naldochristian
Posts: 1
Joined: Thu Nov 02, 2017 6:50 am

Arduino Current Sensor Problem

Post by naldochristian » Thu Nov 02, 2017 7:01 am

Hello everyone, I'm pretty much new with electronic stuffs and Arduino. I want to ask a question about current sensor arduino.
So I've actually set up the current sensor in line with a fan on the cable, and I use the 5A one. I just have the problem that the
analog and digital readings shown by the Serial Monitor of Arduino IDE are just random. When I turned off the fan, it reads the
analog reading 510 to 540, randomly, it happens exactly the same when I turned it on, with the same range 510 to 540 analog
reading. The dgital reading is also not working, it shows HIGH even when it's off.

The fan is about 1/11A big, 220V and 20W. I'm not sure that the current is too low to be read by the sensor, but if it does, is
there any way to 'step-up' the current? Or at least getting the sensor back to work again> (P.S. the sensor is brand new)

Thank You....

n1ist
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Joined: Wed Mar 22, 2006 11:02 am

Re: Arduino Current Sensor Problem

Post by n1ist » Thu Nov 02, 2017 11:40 am

First of all, which sensor? If it is BOB-08882 or BOB-08883 (ACS712), STOP RIGHT NOW AND DISCONNECT IT. Spacings between tracks on that board and the ground plane are too close to safely use it on 220V (or 120V, for that matter). Using either board on line voltage may at best destroy your computer, and at worst be lethal. Yes, the chip is rated at 2.1kV isolation. The PCB design is far from that. I have sent them a comment asking them to put a safety note on the product pages.

If not that one, which is it and how is it connected to the Arduino and the fan?

I would switch to a non-invasive current sensor like SEN-11005. To step up the sensitivity, just pass the wire through the core multiple times.
/mike

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