| 摘要 |
<p>A position sensing device for use on determining the location of a control handle or joy stick includes a dielectric element movable between a pair of spaced-apart printed circuit boards which have formed thereon a plurality of capacitors surrounding a central axis. As the control handle moves, the dielectric element, preferably a disk formed of Teflon®, covers more or less of the area between the individual capacitor elements, causing the capacitance of each to change. The capacitors are preferably arcuate segments on at least one of the boards which are radially spaced and surround from a reference location. In one embodiment, two sets of radially spaced apart arcuate segments are included to provide redundancy. The capacitor elements may be embedded in the boards to minimize wear. A capacitance measuring circuit determines the actual capacitance of each capacitor and a position determining circuit uses the capacitance values to determining the actual position of said control element with respect to the central axis.</p> |
