I am trying to identify an IC that can sit in proximity to an appliance power cord (120VAC) and simply detect if current is flowing or not. On-off output is fine; no need to actually measure the current flow.
I thought this would be a trivial exercise, but it seems not so simple. I have seen a number of examples using Arduino, or similar, but this seems like overkill for this application.
Can someone please point me in the right direction for a simple non-contact integrated circuit that outputs on/off, depending on AC current flow in a nearby conductor?
I have been looking at current sensors, like ACS712). But these seem to need current flowing through, rather than just proximity.
So then I looked at standard Hall effect sensors. I thought a unipolar version would provide an output signal proportional to average current, which should work in my application. But reading the spec sheet on US5881 seems to indicate the output depends on polarity of the field. I think this will fluctuate constantly for AC, rather than giving an average current value output.
Best Answer
Your whole requirement is "hit" by the problem that any current flowing into the load on one wire is also flowing back from the load on the other wire. These two identical currents (passing through identical wires) cause magnetic fields that cancel each other at quite small distances from the load's power cord.
So, the above method is largely unsuitable and unpredictable.
What people actually do is separate live and neutral feeds and measure the magnetic field produced by only one of these wires. Current transformers or hall effect sensors are used. However, from the sound of it this is not an option to you so good luck in finding a magical method.