Miniature crossed coil gauge having an active flux ring

A crossed coil gauge comprising:

• a shaft oriented along a shaft axis;
• an oriented rare-earth magnet mounted to rotate with the shaft along the shaft axis, the magnet supplying magnetic flux directed transverse to the shaft axis, the magnet shaped as a circular cylinder having a radius and a length, wherein the length of the magnet exceeds the radius;
• a gauge housing which houses the magnet and the shaft, the gauge housing providing support for rotation of the shaft and the magnet about the shaft axis, the gauge housing including an upper bobbin, a lower bobbin, and a damping ring disposed around the magnet and retained between the upper bobbin and the lower bobbin, wherein the damping ring provides eddy-current generated damping in response to rotation of the magnet relative thereto;
• a first coil and a second coil each wound around the gauge housing, wherein the first coil is wound generally perpendicular to the second coil and wherein the first coil and the second coil encircle the damping ring;
• and
• a flux ring, disposed around the first coil and the second coil and axially aligned with respect to the magnet and the shaft, said magnet having sufficiently high strength and said flux ring being mounted in sufficiently close proximity to the first and second coils to redistribute the magnetic flux supplied by the magnet such that the magnetic flux density near the first coil and the second coil is increased by at least 60% in comparison to the magnetic flux density supplied by the magnet without the flux ring.