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Magnetic Polarity Reversal for Hall Effect Device Control

IP.com Disclosure Number: IPCOM000075808D
Original Publication Date: 1971-Nov-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Braun, RJ: AUTHOR [+2]

Abstract

Inexpensive Hall effect devices have relatively broad magnetic operating ranges and the control of field-density levels for positive ON and OFF control of such devices becomes a significant problem. The arrangements shown in the drawings provide for changing the magnetic flux from a negative to a high positive value over a very short travel distance of the operating member, and hence, provide improved reliable switching of the Hall effect devices.

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Magnetic Polarity Reversal for Hall Effect Device Control

Inexpensive Hall effect devices have relatively broad magnetic operating ranges and the control of field-density levels for positive ON and OFF control of such devices becomes a significant problem. The arrangements shown in the drawings provide for changing the magnetic flux from a negative to a high positive value over a very short travel distance of the operating member, and hence, provide improved reliable switching of the Hall effect devices.

In Fig. 1 there is shown a bar magnet 3 with a center pivot and two pole faces 4 and 5, designated N, and S, fitted with a suitable operating handle 6. The Hall device 7 is placed in the air gap of two stator pole pieces 8 and 9 of soft iron. The permanent magnet places its north pole against one stator pole piece and its south pole against the other stator pole pieces. Toggling the magnet to its other position, reverses the magnetic polarity of the stator poles with the resultant magnetic polarity change through the air gap in which the Hall device 7 is located. The continuous magnetic attraction to one or the other stators or pole pieces provides a maintained toggle position function that keeps the Hall device conducting, or cut off, dependent upon the magnetic polarity across the air gap. Other means of pivoting the magnet may be utilized, such as elastomeric supports, or cantilever springs, and the like.

In Fig. 2 a pivoted permanent magnet 3 is mounted on a...