Planar coil linear actuator and transducer
OwnerAnil K. Raj, Timothy L. Hutchensoninventors
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Abstract
A planar coil linear actuator/transducer. A stack of individually driven planar coils are used. A common core passes through the center of the stack of coils. A mobile magnet resides in the core. The coils are selectively energized in order to drive the magnet as desired. It is possible to control both frequency and amplitude by controlling the motion of the magnet. In a preferred embodiment, each planar coil is created as a copper (or other conductive material) trace on a multi-layer printed circuit board.
Claims20
An actuator for converting electrical signals into tactile signals, comprising:
- (a) a magnet movable along a core axis;
- (b) a plurality of planar coils, each of which includes a core and a spiral planar winding lying in a plane that is perpendicular to said core and wound around said core;
- (c) wherein said plurality of planar coils are stacked together with said cores of said planar coils combining to form an open core aligned with said core axis, said open core having a first end and a second end;
- (d) wherein each of said planar coils has a center tap;
- (e) said magnet being free to move within said core with no passive biasing device affecting a position of said magnet within said bore;
- (f) a control system providing a voltage for each of said planar coils, said control system being configured to switch off each of said planar coils and use said center tap for each of said planar coils to determine a current position of said magnet, thereby providing closed-loop control;
- and
- (g) said control system configured to selectively energize each of said planar coils in order to produce a desired oscillating motion of said magnet.
An actuator for converting electrical signals into tactile signals, comprising:
- (a) a magnet movable along a core axis;
- (b) a plurality of planar coils, each of which includes a core and a planar winding lying in a plane that is perpendicular to said core and wound around said core;
- (c) wherein said plurality of planar coils are stacked together with said cores of said planar coils combining to form an open core aligned with said core axis, said open core having a first end and a second end;
- (d) wherein each of said planar coils has a center tap;
- (e) said magnet being free to move within said core with no return spring affecting a position of said magnet within said bore;
- (f) a control system providing a voltage for each of said planar coils, said control system being configured to switch off each of said planar coils and use said tap for each of said planar coils to determine a current position of said magnet, thereby providing closed-loop control;
- and
- (g) said control system configured to selectively energize each of said planar coils in order to produce a desired oscillating motion of said magnet.
Dependencies are inferred from the claim text.