Patent ID: 8674685
Filing Date: 2014-03-18
Classification: G01F

Abstract:
1. A magnetic flux position sensor comprising: a primary coil for generating a magnetic flux; a secondary coil for sensing magnetic flux, wherein the primary and secondary coils are substantially concentric, wherein the primary coil is spaced from the secondary coil by an annular passage having a first end and a second end, and wherein a characteristic of at least one of the primary and secondary coils decreases substantially continuously between the first end and the second end; a magnetic flux conductor positioned in the annular passage so as to be slidable from the first end to the second end for conducting magnetic flux from the primary coil to the secondary coil, wherein magnetic flux transferred from the primary coil to the secondary coil varies as a function of position of the magnetic flux conductor; a current driver electrically connected to the primary coil; and output circuitry connected to the secondary coil for producing an output that is a function of position of the magnetic flux conductor along the annular passage, the output circuitry including an ammeter for sensing current in the secondary coil and a measurement algorithm that relates magnitude of current sensed in the secondary coil to the level of liquid in the reservoir.