Abstract: A motor control system includes a microcomputer for executing a so-called software servo-control, and the microcomputer receives a speed signal and a phase signal from the motor. In the microcomputer, speed error data is evaluated on the basis of the speed signal, and speed integration data is evaluated on the basis of the speed error data and a first reference signal, and phase integration data is evaluated on the basis of the phase signal and a second reference signal. The speed error data, the speed integration data and the phase integration data is synthesized, so as to obtain motor control data.

Abstract: An impact load controller (28) compensates for the speed drop of a drive motor (12), which speed drop is caused by a load disturbance applied to the drive motor (12). A change in the dynamics of a speed controller (30, 34) in a speed regulator system for a stand in a tandem rolling mill is initiated by detecting a speed error (WE) which is greater than a predetermined speed error value and is removed after the speed error has been reduced to a predetermined value. The controller (28) is a pure rate controller whose input is converted into a rate change in speed error, which is multiplied by a gain factor. The resultant gain value product is initially increased by a predetermined factor to provide a high input signal to the (PI) speed controller (34) of a multi-loop speed regulator system for the drive motor (12), and to precharge a low pass filter.

Abstract: A fire-fighting system in which a liquid chemical foamant is introduced into the water stream in varying amounts so as to maintain a predetermined percentage mixture irrespective of variations in the water flow includes a motor-driven pump where the motor is controlled over a first speed range by pulse width modulating the drive to the motor and over a second speed range, producing intermittent motion, by burst width modulating the drive signal when it is operating at its minimum pulse width modulated duty cycle. Using this technique the range of available motor speeds is extended well beyond that which can be achieved using pulse width modulation of the motor drive signal alone.

Abstract: A solid state controller is mounted directly to a permanent magnet, brushless DC motor. The controller operates the motor at constant torque and variable speed. Speed is determined in accordance with density of the through flow. The motor and controller can be employed to circulate fluid in a circulation loop having variable pressure.

Abstract: A pulsating D.C. voltage is developed by a rectifier 86 and is filtered by a capacitor 100 to facilitate application of a relatively smooth, enhanced D.C. voltage to a motor 106.The charged voltage of capacitor 100 is applied across a series circuit which includes a rheostat 118, a resistor 126 and motor 106. When the CEMF of motor 106 drops as a result of a decrease in motor speed, a disc 122 is biased through the voltage appearing across rheostat 118 and resistor 126 to cause an SCR 116 to fire. When SCR 116 fires, the voltage of capacitor 100 supplies a boost of power to motor 106 to overcome the decrease in motor speed.A circuit 212 prevents an overspeed of motor 106 from occurring while braking circuits 264, 266 and 268 provide for a dynamic braking effect when the motor is a universal motor.

Abstract: A velocity control apparatus according to the invention is used in order to acccept feedback data, for velocity control of a servomotor or the like. The disclosed apparatus provides velocity information in the form of discrete data from a pulse coder or the like, and forms a prescribed control command by digitally processing the data in a microprocessor. In a case where the above mentioned data are sampled at a predetermined sampling rate during a processing period so as to accommodate processing by the microprocessor, a lag element results when the data are accepted within the computer as velocity information which causes an inaccuracy in servomotor control. Accordingly, a detection signal forming unit (5) processes the discrete count data as the sum of count data synchronized to the sampling rate which is the processing period subdivided into a fraction, in which fraction the denominator is an integer.

Abstract: In construction of a peripheral-magnetization type magnetic encoder having a rotary spindle and a magnetic head, a resin housing is formed by insert moulding so as to embrace the spindle leaving a slight tubular clearance to allow free axial rotation of the spindle, thereby providing direct, simple and stable support to the rotary spindle for enhanced precision in direction.

Abstract: A circuit for speed monitoring, particularly for fan drives. A detection device for producing an input signal sequence is provided which has a speed-dependent repetition frequency. The circuit also has a signal converter for converting the input signal sequence into an output signal whose amplitude is a function of the repetition frequency of the input signal sequence. There is also an evaluation circuit, having at least one threshold value element responsive to the output signal of the signal converter and which responds if the output signal amplitude reaches a value corresponding to a drop below a predetermined minimum speed or a rise above a predetermined maximum speed.