I am attempting to pass current from a static part to a moving part via induction across a 1 mm air gap. Once that works I would like to use the current on the moving part to power an IR LED pointed at a mated IR sensor and then receive the resistance value from the IR sensor and pass the 'value' back to the static part via inductance over the 1 mm air gap. The purpose of this is to be able to optically sense a physical interference from sensors mounted on a sliding shaft. The current circuit has ~9v DC and regulated 5v DC source and runs off of a PIC microcontroller. How do I generate an AC signal from a battery with a PIC to create the inductance? Or is there a way to create an inductance from a DC source? How many windings of what thickness magnet wire would I need for the current to be able to jump the air gap and provide enough current for the LED, the IR sensor and the re-inductive 'output'?