DC commutatorless motor

A DC commutatorless motor comprising:

• three-phase stator windings;
• a rotor having magnetic poles, the number of said magnetic poles being 2n (where n is a natural number of 2 or more), one of said magnetic poles comprising a first region of one of magnetic polarization and a second region within said first region, wherein said second region is not magnetized;
• three detection devices disposed in the vicinity of said rotor, said detection devices being responsive to a magnetic field generated by said magnetic poles and said portion;
• first to third amplifying means for amplifying respectively the outputs of said three detection devices;
• first to third subtracting means for obtaining respectively the difference of the outputs of two of said first to third amplifying means;
• an adding means for adding the outputs of said first to third subtracting means;
• and
• a signal means for generating a pulse per one revolution of said rotor on the basis of the output of said adding means.

A DC commutatorless motor comprising:

• three-phase stator windings;
• a rotor having magnetic poles, the number of said magnetic poles being 2n (where n is a natural number of 2 or more), one of said magnetic poles comprising a first region of one magnetic polarization and a second region within said first region, wherein said second region is oppositely magnetically polarized to said first region;
• three detection devices disposed in the vicinity of said rotor, said detection devices being responsive to a magnetic field generated by said magnetic poles and said portion;
• first to third amplifying means for amplifying respectively the outputs of said three detection devices;
• an adding means for adding the outputs of said first to third amplifying means;
• and
• a signal means for generating a pulse per one revolution of said rotor on the basis of the output of said adding means.

A DC commutatorless motor comprising:

• three-phase stator windings;
• a rotor having magnetic poles, the number of said magnetic poles being 2n (where n is a natural number of 2 or more), one of said magnetic poles comprising a first region of one of magnetic polarization and a second region within said first region, wherein said second region is not magnetized;
• three detection devices disposed in the vicinity of said rotor, said detection devices being responsive to a magnetic field generated by said magnetic poles and said portion;
• first to third amplifying means for amplifying respectively the outputs of said three detection devices;
• an adding means for adding the outputs of said first to third amplifying means;
• and
• a signal means for generating a pulse per one revolution of said rotor on the basis of the output of said adding means.

A DC commutatorless motor comprising:

• three-phase stator windings;
• a rotor having a number of magnetic poles, wherein the number of said magnetic poles is two times a natural number of 2 or greater, wherein one of said magnetic poles comprises a first region of a magnetic polarization and a second region within said first region, wherein said second region is oppositely magnetically polarized to said first region;
• three detection devices disposed in the vicinity of said rotor, said detection devices being responsive to a magnetic field generated by said magnetic poles;
• first to third amplifying means for amplifying respectively the outputs of said three detection devices;
• first to third subtracting means for obtaining respectively the difference of the outputs of two of said first to third amplifying means;
• adding means for adding the outputs of said first to third subtracting means;
• and
• signal means for generating a pulse per one revolution of said rotor on the basis of the output of said adding means.

A DC commutatorless motor comprising:

• three-phase stator windings;
• a rotor having a number of magnetic poles, wherein the number of said magnetic poles is two times a natural number of 2 or greater, wherein one of said magnetic poles comprises a first region of a magnetic polarization and a second non-magnetized region within said first region;
• three detection devices disposed in the vicinity of said rotor, said detection devices being responsive to a magnetic field generated by said magnetic poles;
• first to third amplifying means for amplifying respectively the outputs of said three detection devices;
• first to third subtracting means for obtaining respectively the difference of the outputs of two of said first to third amplifying means;
• adding means for adding the outputs of said first to third subtracting means;
• and
• signal means for generating a pulse per one revolution of said rotor on the basis of the output of said adding means.

A DC commutatorless motor comprising:

• three-phase stator windings;
• a rotor having a number of magnetic poles, wherein the number of said magnetic poles is two times a natural number of 2 or greater, wherein one of said magnetic poles comprises a first region of a magnetic polarization and a second region within said fist region, wherein said second region is oppositely magnetically polarized to said first region;
• three detection devices disposed in the vicinity of said rotor, said detection devices being responsive to a magnetic field generated by said magnetic poles;
• first to third amplifying means for amplifying respectively the outputs of said three detection devices;
• adding means for adding the outputs of said first to third amplifying means;
• and
• signal means for generating a pulse per one revolution of said rotor on the basis of the output of said adding means.

A DC commutatorless motor comprising:

• three-phase stator windings;
• a rotor having a number of magnetic poles, wherein the number of said magnetic poles is two times a natural number of 2 or greater, wherein one of said magnetic poles comprises a first region of a magnetic polarization and a second non-magnetized region within said first region;
• three detection devices disposed in the vicinity of said rotor, said detection devices being responsive to a magnetic field generated by said magnetic poles;
• first to third amplifying means for amplifying respectively the outputs of said three detection devices;
• adding means for adding the outputs of said first to third amplifying means;
• and
• signal means for generating a pulse per one revolution of said rotor on the basis of the output of said adding means.