Abstract: A speed control apparatus in which for sampling features of a speed fluctuation and generating a speed fluctuation correcting signal, an arithmetic operation can be simplified and can be performed by an inexpensive arithmetic and operation unit, thus requiring no expensive arithmetic operation unit. The speed control apparatus is also capable of reducing torque ripples and speed fluctuations quickly even when the load of an object to be controlled is changed.

Abstract: There is provided position error computing means for sampling an error value between a position detecting signal derived from means for detecting the position of a moving body and a position command signal supplied from outside and for computing a position error value on the basis of two or more past values of said error values. There is also provided a position control apparatus in which the magnitude of a gain of a position control loop is changed according to the above described position error value. Further, there is also provided a signal reproducing apparatus or a magnetic signal reproducing apparatus using the above described position control.

Abstract: In order to provide a speed control apparatus for a movable equipment having small torque ripples and speed variation, the present invention has a speed control means which comprises a driver for providing a current or a voltage having a magnitude corresponding to the instructed speed, a speed detection circuit for detecting a speed on the basis of a signal from the speed detector and a microcomputer for driving the driver by comparing the speed instruction signal with a speed signal obtained from the speed detection circuit. The microcomputer includes a harmonic wave component detecting means for detecting a harmonic wave component contained in a speed variation mode which is obtained from the speed detection circuit and has a function of making the gain of a speed control system variable by the harmonic wave component detected by the harmonic wave component detecting means.

Abstract: A speed control apparatus is provided for controlling a speed of a movable equipment in such a way that the speed of the movable equipment is detected, calculates a deviation value between a detected speed of the movable equipment and a speed instruction signal, and controls the speed of the movable equipment based on the deviation value. The speed control equipment detects harmonic wave components included in the detected speed and reduces the harmonic wave components from the speed instruction signal so as to control the speed of the movable equipment.

Abstract: The stator comprises three phase driving coils and an electric commutator for controlling current to the driving coils. The rotor comprises permanent magnets which are alternately magnetized in N polarity and S polarity. Driving torque is generated corresponding to the current flowing through the driving coils and the permanent magnets. On the surface of the permanent magnet facing to the driving coils, two non-magnetizing portions are provided in each permanent magnet having either N or S polarity.

Abstract: Disclosed is a speed controlling method and apparatus in which a suitable current or voltage command is given to a moving body on the basis of the relation between a speed detection signal obtained by detecting the speed of the moving body and an externally supplied speed command signal.