I'd like to know how i could detect low voltage signals emitted over a coil.
like you have a 1 meter wire layed in a carpet, and when the coil hovers over it, it will trigger a signal and let me know when it's there.
it should be able to be under a carpbet or lets say 3-4mm thick wood or other fibers.
anyone heared of a project like this, or has an idea how to do it?
i was thinking of reusing a em detector with 3x BC 547 transistors on the line, then hover over with a simple coil. but before i go further, maybe someone else already did it. like for robot to limit the movement area.