초록 ▼

A position sensor has a shaped dual magnet structure carried upon a pole piece having a generally "c" shaped cross-section. The magnet and pole piece define a generally circular linear field which is concentric about the axis of rotation of the complete rotor. A Hall effect device is inserted into t

A position sensor has a shaped dual magnet structure carried upon a pole piece having a generally "c" shaped cross-section. The magnet and pole piece define a generally circular linear field which is concentric about the axis of rotation of the complete rotor. A Hall effect device is inserted into the open portion or gap between the two magnets and is exposed to a well defined field. Through the use of selected geometries and particular magnet materials, a precise, compact and yet tolerant magnetic circuit is produced.

대표청구항 ▼

[ We claim:] [1.] A rotary position sensor comprising:a) a housing;b) an assembly for providing a closed magnetic circuit including:b1) a first magnet;b2) a second magnet;b3) a magnetically permeable pole piece interconnecting the first and second magnets; andb4) a varying dimension air gap defined

[ We claim:] [1.] A rotary position sensor comprising:a) a housing;b) an assembly for providing a closed magnetic circuit including:b1) a first magnet;b2) a second magnet;b3) a magnetically permeable pole piece interconnecting the first and second magnets; andb4) a varying dimension air gap defined between the first magnet and the second magnet;the first and second magnets being structured and dimensioned to provide the varying dimension air gap and to form a variable magnetic field coupled therebetween;the assembly being rotatably mounted in the housing about an axis, the axis being generally parallel to the magnetic field coupled between the magnets;c) a magnetic field sensing means positioned in the air gap for sensing the variable magnetic field coupled between the first and second magnets; andd) a first permanent magnet lip portion on the first magnet and a second permanent magnet lip portion on the second magnet; the first lip portion and the second lip portion being structured and dimensioned to expand the variable magnetic field coupled between the magnets.