This is for a friend who has a work related problem.
Tubing goes through a "metal detector" to detect metal, but the metal parts tend to get lodged, and they'd like to increase the size of the tube. Unfortunately larger sized tube will not fit through the "metal detector" (which is a ring and looks like a custom built module).
My idea was to bypass the entire thing, use a larger tube with a metal detector, and the output go to a coil (?) that will trick the real detector into thinking it has a piece of metal passing by it.
I thought of a metal detector that outputs a high when it detects (or some sort of pulse) feeding the base of a transistor, a pull up on the collector feeding a coil that sits in the actual metal detector, and obviously a snubber diode across the coil.
This way the metal triggers the metal detector, turns on the transistor, energizes the coil with the pulse, creates a magnetic field, and turns off.