I'm working on a project where I need to sense if a circuit is in operation on a wide range of vehicles. My plan so far is a current sensing clamp, and an Arduino micro listening for the current draw on that wire to be above 0ma. (or a more reasonable threshold to be determined)
I've looked into the normal clamp meters for AC applications, but they dont work on DC. I also need this to be non invasive, and able to be quickly attached to and from various wires – so must be a split loop pickup or similar… These types of current sensors wont work, as they are invasive.
I'm thinking some kind of a coil on an Arduino analog input, that is clipped onto the wire to monitor – but I'm at a loss as to what this coil needs to look like – and I'm not getting anywhere trying various random coils hooked up to an Arduino and looking for any change in analog read…
Can anyone offer any help on this?
Best Answer
NVE corp makes GMR (Giant Magnetoresistance) based sensor ICs that can non-invasively sense the current in a wire that is in close proximity to the chip. Usually they sense a PCB trace running under the chip, but you could perhaps make a PCB with a slot under the IC and clamp the wire into the slot.
They even have a video app note for using their AAL024 sensor with the Arduino.