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Temperature Compensated Permanent Magnet

IP.com Disclosure Number: IPCOM000077855D
Original Publication Date: 1972-Oct-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Lissner, RW: AUTHOR

Abstract

A permanent magnet structure, having inner and outer pole pieces 10 and 12, respectively, that encompass a working gap 14, incorporates bimetal strips 16 which are positioned flat against the magnet edges. The bimetal strips effectively short part of the magnet structure, thereby decreasing the working gap density. When the temperature of the magnetic structure increases during operation, such as in a voice coil motor assembly, the bimetal strips will move away from the edge of the magnet pieces, thereby decreasing the partially shorted oath and compensating for the decreased flux from magnets resulting from the temperature increase. As a result, the working gap will experience a more stable flux density during temperature excursions.

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Temperature Compensated Permanent Magnet

A permanent magnet structure, having inner and outer pole pieces 10 and 12, respectively, that encompass a working gap 14, incorporates bimetal strips 16 which are positioned flat against the magnet edges. The bimetal strips effectively short part of the magnet structure, thereby decreasing the working gap density. When the temperature of the magnetic structure increases during operation, such as in a voice coil motor assembly, the bimetal strips will move away from the edge of the magnet pieces, thereby decreasing the partially shorted oath and compensating for the decreased flux from magnets resulting from the temperature increase. As a result, the working gap will experience a more stable flux density during temperature excursions.

Alternatively, a magnetizable piece of material with a high-temperature coefficient of saturation flux density may be placed against the magnet structure to provide a partial short.

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