The instantaneous angular velocity of a rotating shaft or the like is translated from the relative rotation of a mark carrier, having a scale of marks, and a sensing device. A series of signals are produced and processed in a calibrating run and thereafter in a series of operating runs. In the calibrating run, the time distance of the sensed signals between at least one pair of the marks is measured and from it a calibrating value is calculated corresponding to the absolute angular distance between the marks and thereafter stored. During the operation runs, the instantaneous time distance of the sensed signals between the marks is measured and the instantaneous velocity is obtained by comparing it with the stored calibrating value.
In an optical disk reproducing apparatus 1 in which a mounting tray slides to a projected position and a contained position with respect to the apparatus main body, to slide the mounting tray at a series of continuous predetermined speeds independent of change in environmental conditions. A series of continuous application voltages, to be supplied from a drive source 8 to an output motor 16 so as to slide a mounting tray 3 at a series of continuous speeds, for use in an use environment of the highest frequency of use where the mounting tray 3 slides at a series of continuous speeds, are preset-stored in computation means 21. When the mounting tray 3 is actually slided by an output from the output motor 16, if the preset speeds are not attained, the computation means 21 outputs a command signal to the drive source 8 to appropriately correct the application voltages to the output motor 16.
A laundry appliance includes apparatus for analyzing the eccentricity of a rotatable member with respect to its design rotational axis when subjected to dynamic unbalance forces. An indicator is rotatable with the rotatable member and includes a predetermined detectable pattern. A sensor is juxtaposed to the detectable pattern and is spaced a predetermined radial distance from the design rotational axis of the rotatable member and indicator. The sensor is cooperable with the detectable pattern for producing an electrical signal corresponding to passage of the detectable pattern during rotary movement of the indicator to generate a stream of electrical signals representing the relative degree of radial displacement of the rotatable member from the design rotational axis. Control apparatus includes a microcontroller in circuit association with the sensor. The microcontroller is operable for receiving and analyzing the stream of electrical signals from the sensor for determining the radial displacement of the rotatable member from the design rotational axis by analyzing changes in the stream of electrical signals.
An angular position change of the linearly driven drive system is proportional to its particular running time. In the process there is determined a desired value of the running time of the drive system belonging to a desired-value angular position (.alpha..sub.S), the drive system is thereupon started and its running time is measured and, when a measured value of the running time is equal to the determined desired value of said running time, the drive system is stopped. By this process the dependability of the drive system is improved and the costs of the latter are reduced.
In a motor speed controller (which, in accordance with rotations of a rotor having a drive magnet, detects an induced voltage in each of drive coils in m phases less than the number of drive magnets wound around a stator, generates speed signals which includes m square wave pulses at every 360.degree. in electrical angle, based on the induced voltage, and controls motor driving voltage applied to each of the drive magnets according to the speed signals), the present invention employs a configuration comprised of: period detecting circuit for detecting periods between rising edges or falling edges of a pulse that occurs every (P-1) pulse of the pulses included in the speed signals; speed deviation signal generating circuit for generating speed deviation signals, comparing detected periods to a predetermined reference period; and drive control circuit for correcting the motor drive voltage, which is applied to said drive coils, based on the speed deviation signals so that the rotating speed of the rotor meets a targeted rotating speed.
A process of adapting mechanical tolerances of a transmitter wheel provided with a plurality of approximately equidistant markings which are sensed by a pick-up supplying a pulse train whose time interval is measured and stored, includes connecting a transmitter wheel with a rotating shaft of an internal combustion engine, carrying out a check as to whether or not the internal combustion engine is in thrust operation, and placing a second and following time intervals in relation to a first time interval when the thrust operation is detected.
