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    3.
    发明专利
    未知

    公开(公告)号：FR2524729A1

    公开(公告)日：1983-10-07

    申请号：FR8305437

    申请日：1983-04-01

    Applicant: SONY CORP

    Inventor： UZUKA MITSUO

    IPC: H02P6/06 ,  H02P6/08 ,  H02P6/18 ,  H02P6/182 ,  H02P6/21 ,  H02P6/02

    Abstract: A driving circuit for a brushless DC motor is connected to energize the plurality of stator windings by detecting induced voltages in windings adjacent an energized winding, mixing these detected voltages in predetermined ratios, and comparing the mixed voltages with a reference level, in order to provide switch controlling signals fed to switches arranged between each of the plurality of stator windings and the energization source. Individual detectors to detect rotor position corresponding to the winding being energized are not required and delay circuits used to provide sequential pulses are also eliminated thereby promoting fabrication of the invention using integrated circuit technology.

    4.
    发明专利
    未知

    公开(公告)号：IT8221814D0

    公开(公告)日：1982-06-11

    申请号：IT2181482

    申请日：1982-06-11

    Applicant: SONY CORP

    Inventor： UZUKA MITSUO

    IPC: H02P6/24 ,  G11B15/22 ,  G11B15/665 ,  H02P6/06 ,  H02P6/08 ,  H02K

    Abstract: A brushless DC motor of the type including a rotor having a magnet for generating magnetic flux of alternating magnetic field polarities in a rotary path about its axis of rotation and a stator coaxial with the rotor and having a plurality of coils of respective phases in linking relation to the magnetic flux and adapted to be energized for the flow of current therethrough so as to produce a rotational torque, is provided with a control circuit in which switching transistors are connected with the coils of respective phases and are selectively turned ON in response to respective switching signals for energizing the respective coils, a switching signal generating circuit is normally responsive to the rotational position of the rotor for periodically changing its condition and thereby providing the switching signals to the switching transistors, and an additional switch device is connected to the switching signal generating circuit and is actuable to fix the condition of the latter so that only one of the switching transistors is continuously turned ON for energizing only the respective coil and thereby locking the rotor against rotation. Such locking of the rotor against rotation is particularly desirable in the case where the brushless DC motor is provided to directly drive a reel mount in a video tape recorder (VTR) or similar apparatus in which it is desired to prevent rotation of the reel mount during tape loading and unloading operations.

    7.
    发明专利
    未知

    公开(公告)号：BR8203407A

    公开(公告)日：1983-05-31

    申请号：BR8203407

    申请日：1982-06-09

    Applicant: SONY CORP

    Inventor： UZUKA MITSUO

    IPC: H02P6/24 ,  G11B15/22 ,  G11B15/665 ,  H02P6/06 ,  H02P6/08 ,  H02P3/08

    Abstract: A brushless DC motor of the type including a rotor having a magnet for generating magnetic flux of alternating magnetic field polarities in a rotary path about its axis of rotation and a stator coaxial with the rotor and having a plurality of coils of respective phases in linking relation to the magnetic flux and adapted to be energized for the flow of current therethrough so as to produce a rotational torque, is provided with a control circuit in which switching transistors are connected with the coils of respective phases and are selectively turned ON in response to respective switching signals for energizing the respective coils, a switching signal generating circuit is normally responsive to the rotational position of the rotor for periodically changing its condition and thereby providing the switching signals to the switching transistors, and an additional switch device is connected to the switching signal generating circuit and is actuable to fix the condition of the latter so that only one of the switching transistors is continuously turned ON for energizing only the respective coil and thereby locking the rotor against rotation. Such locking of the rotor against rotation is particularly desirable in the case where the brushless DC motor is provided to directly drive a reel mount in a video tape recorder (VTR) or similar apparatus in which it is desired to prevent rotation of the reel mount during tape loading and unloading operations.

    8.
    发明专利
    未知

    公开(公告)号：DE3107623A1

    公开(公告)日：1981-12-24

    申请号：DE3107623

    申请日：1981-02-27

    Applicant: SONY CORP

    Inventor： UZUKA MITSUO

    IPC: H02P6/06 ,  H02P6/08 ,  H02P6/28 ,  H02P7/28

    Abstract: A drive circuit for a brushless DC motor assures that the stator coils of the motor do not generate unwanted electromagnetic noise, but does not sacrifice efficiency of the motor. The drive circuit can include an input circuit to which a rectangular switching signal is applied, a circuit including a drive transistor providing stator drive current in response to the input switching signal, and an RC smoothing circuit to impart sloping leading and trailing edges to the drive current so that the drive current assumes a somewhat sinusoidal shape and the electromagnetic noise is avoided. In order to prevent the motor efficiency from dropping under low-torque and high-speed conditions, the delay times for the leading and trailing edges are controlled to increase or decrease in dependence upon the load to the motor. In one embodiment, the collector-emitter voltage of the drive transistor is sensed and this voltage is furnished to a control transistor so that the latter adjusts the level of the input switching signal according to the sensed voltage level. Preferably, the base current applied to the drive transistor is kept near the saturation level.

    DC MOTOR
    9.
    发明专利
    DC MOTOR 未知

    公开(公告)号：CA1110687A

    公开(公告)日：1981-10-13

    申请号：CA300375

    申请日：1978-04-04

    Applicant: SONY CORP

    Inventor： UZUKA MITSUO

    IPC: H02K1/22

    Abstract: DC MOTOR A DC motor having a rotor which rotates about an axis and a stator. The motor comprises at least two coils adapted to be energized for current to flow therethrough, each coil having a first current path portion through which current flows in a first direction and a second current path portion through which current flows in a second, opposite direction. A magnetic flux generator includes at least one pair of circumferentially disposed magnetic poles for generating flux of alternating magnetic field polarity in a rotary path about the axis, the magnetic flux linking each coil such that if a coil is energized throughout a region of magnetic flux of predetermined polarity, a rotational torque of predetermined direction is produced through a range having an electrical angle greater than 180.degree.. A circuit alternately energizes the coils for current to flow through each energized coil for a duration substantially equal to an electrical angle of 180.degree. when the energized coil is within the range of the torque of predetermined direction. In one embodiment, each coil is wound toroidally on a toroidal core, and the coils are separated by an electrical angle of 180.degree.. In this embodiment, one magnetic polarity of the magnetic flux is asymmetric with respect to the other magnetic polarity thereof. In another embodiment, the first and second current path portions are disposed on substantially the same cylindrical surface concentric about the axis, and the first and second current path portions are separated from each other by an electrical angle less than 180.degree.. -i-

    BRUSHLESS MOTOR DRIVING CIRCUIT
    10.
    发明专利
    BRUSHLESS MOTOR DRIVING CIRCUIT 未知

    公开(公告)号：CA1086376A

    公开(公告)日：1980-09-23

    申请号：CA283732

    申请日：1977-07-29

    Applicant: SONY CORP

    Inventor： UZUKA MITSUO

    IPC: H02P6/06 ,  H02P6/08 ,  H02P6/10 ,  H02P6/18 ,  H02P5/00

    Abstract: BRUSHLESS MOTOR DRIVING CIRCUIT A driving circuit for a brushless motor of the type having a permanent magnet rotor and plural phase stator windings. The driving circuit includes position detectors for detecting the rotary position of the rotor. Switching devices are provided for supplying driving currents in sequence to the plural phases of the stator windings in accordance with the position of the rotor. The durations of the driving currents are controlled such that a portion of such currents flowing through adjacent phases are overlapped when the motor is started up; but the duration of each driving current is reduced as the motor approaches a normal speed so as to correspondingly reduce the overlapped portions. Preferably, the durations of the currents are reduced as the speed of the motor increases until such currents no longer have overlapped portions. -i-

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