Series Connected Motors Patents (Class 318/113)
  • Patent number: 4012674
    Abstract: A ribbon drive and motor control system in which the instantaneous speed and torque output of a pair of motors are controlled interdependently to bidirectionally transfer ribbon or other web material between a pair of storage reels mechanically coupled to the motors at a uniform ribbon velocity and tension. The motors are electrically excited in series to rotate in the same direction with the back electromotive force of one motor being used to vary the instantaneous excitation voltage applied to the other motor, while drag from said other motor is imparted to the ribbon to control the speed of the first motor. Compensation for variation of the radii of ribbon on the reels during operation is accomplished automatically by variation of motor torque and velocity to minimize variation in ribbon tension and ribbon velocity. A bridge switch actuated by signals initiated by electrical contacts near the ends of the ribbon causes the motors to reverse direction.
    Type: Grant
    Filed: April 7, 1975
    Date of Patent: March 15, 1977
    Assignee: Computer Peripherals, Inc.
    Inventors: Merlin D. Spitsbergen, James G. Hughes