Patents by Inventor Mitsunori Arakawa

Mitsunori Arakawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Control circuit for a DC motor
    Patent number: 5220634
    Abstract: A DC power supply for a DC motor is controlled by a drive transistor. An "ON" state of the drive transistor is maintained by a comparator which compares a terminal voltage at a point between the DC motor and the drive transistor with a reference voltage supplied from the power supply. A clock pulse is applied to the drive transistor to make it periodically turn off in order to detect an induced voltage depending upon the rotation rate of the DC motor. The drive transistor returns to turn off upon stopping the rotating DC motor by force.A regulator is provided between the power supply and the reference voltage. A restraint torque and a rotation rate control means are also provided.Alternatively, a pulsating power supply is provided instead of the DC power supply and the clock.
    Type: Grant
    Filed: January 16, 1992
    Date of Patent: June 15, 1993
    Assignee: Kabushiki Kaisha Riken
    Inventors: Osamu Yaguchi, Mitsunori Arakawa