10A current sensor (AC) for arduino controlled mains switch

Hello all.

My first post here, so please go a little easy on me.

I'm just starting my journey with arduino.
I need to find a 10A AC current sensor for a project that I will be working on.

I have found loads of 5A , 20A and 30A ones. No 10A ones.

What the project will be (hopefully) is an arduino controlled current sensing mains switch.
It will be used to detect a car charger entering standby state then wait 60 sec (false trigger prevention) before turning off the output to the charger. Maximum current will be around 7A @240v.

I have searched eBay, banggood and google for a suitable 10A sensor.
I'm thinking the 20A and 30A units will not have as good a resolution as a 10A unit ?
Maybe is is an incorrect assumption on my part.

Standby state is around 75W @240v. That would be about 30mv on a 10A sensor with a 1V scale ( I think).

Can someone please point me in the direction of a suitable sensor ?

No doubt I will be back later to get assistance with the program code.
That can wait till I have all of the parts.

So far I have the arduino itself (duinotech mega 2560) a 10A relay, the power supply for the arduino, an LCD screen (16x2 Backlit), a rotary encoder and some jumper cables.

Thanks in advance


What has "resolution" to do with anything when all you are looking for is a change in current?


The Hall effect sensors from Pololu are easy to use and work very well.

The +/- 15 A sensor should be fine for your project, but since you are looking for a standby state, the +/- 5 A sensor would offer better resolution.

The ACS devices tolerate up to 5X current overload, so when using the 5A sensor, you could ignore the overload under 7A charging conditions.

Sounds like you're looking for a current transformer.

Here's one source.