Abstract: A system (20) for controlling deceleration of a motor (22) during an abrupt power-off condition includes a processor (40), a motor control circuit (50), and a secondary power source (70). During normal power-on operation and based on currently prevailing operation parameters, processor (40) routinely generates a contingent motor-governing deceleration signal for potential use in governing motor (22) should the power-off condition occur. In response to the occurrence of a power-off condition, motor control circuit (50) controls motor (22) in accordance with the contingent motor-governing deceleration signal to achieve orderly deceleration. Secondary power supply circuit (70) provides power to motor control circuit (50) during the power-off condition.
Abstract: A method for dynamically braking a motor, the motor having a plurality of terminals and receiving an input alternating current voltage waveform, by detecting the zero crossing of the input alternating current voltage waveform and for a plurality of position of the input alternating current waveform: sampling a voltage waveform appearing at a terminal of the motor to develop a sampled value for the position, comparing the sampled value for the position to a reference value for the position and setting a flag if the reference value for the position matches the sampled value for the position, introducing a delay period and generating a gating pulse to fire a silicon controlled rectifier to provide a pulse of braking current to the alternating current motor and then halting the braking of the motor if the flags for each of the plurality of positions are set. Also an electronic dynamic brake assembly operable in a SLAVE mode, a PRE-STOP mode, a HOLDING mode and a MASTER mode.
Abstract: An apparatus for braking a rotary component of a fiber processing machine includes an asynchronous motor having a stator winding and an output shaft connected to the rotary component; a direct current generating device having an output connectable to the stator winding for applying an electric braking torque to the motor; and a switching arrangement for selectively connecting the stator winding to an alternating current source for normally driving the motor or to the output of the direct current generating device for electrically braking the motor.
Abstract: A control device is associated with a dynamic balancing machine for indexing a rotor being examined for unbalance. The control device determines the angular position of unbalance of the rotor during an unbalance measurement run and stops the rotation of the rotor while bringing it to a stop at an angular position related to the determined angular position of unbalance.
Abstract: A spindle motor stop control device applies a reverse torque braking force to the spindle motor to effect stopping of the motor. A speed detector detects when the number of rotation of the motor has slowed to 1/n of a predetermined number of rotation and issues a detection signal. The time period beginning with the application of the reverse torque braking force until the issuance of the detection signal is measured. Then, a time period t=T/(n-1) is calculated and the reverse torque braking force is continued for the time, t, and then removed.
Abstract: A position of an actuation unit of a robot and a speed of a motor for driving the actuation unit are detected. A speed reference is produced on the basis of a deviation between a movement value and a position detected. Further, a torque reference is produced on the basis of a deviation between the speed reference and a speed detected. The motor for driving the actuation unit is subjected to current control. The magnitude of the torque reference is limited by a limiter. This limiter operates only when a command for allowing the robot to be subjected to emergency stop is received, and carries out limiting operation on the basis of a function which rises from the time point when the command is received.
Abstract: In a tape drive system, a dynamic brake control circuit provides dynamic braking for slowing and stopping an associated tape reel and motor system in the event of a power failure. Upon sensing a power failure, the electrical energy stored in a capacitor supplies electrical energy to enable the control circuit, which in turn supplies a controlled conductive path for the flow of a dynamic braking current due to the back electromotive force signal generated by the motor, to effect the controlled dynamic braking of the drive motor to a stop.
Abstract: An SCR motor speed control system is provided with circuitry for fast braking of the motor. The circuitry senses when it is desired to stop the motor and simultaneously short circuits the motor armature and applies half-wave rectified line voltage to the motor field windings.
Abstract: A circuit for electronically braking an AC motor. The circuit includes a controlled rectifying means for applying DC to the motor and a control means for turning the rectifying means on after deactuation of the motor for a timed interval determined by the charging rate of a timing capacitor through a variable resistance.
Abstract: A circuit breaker motor operator control circuit utilizes the voltage developed across a dynamic braking resistor during breaking of a permanent magnet DC motor to prevent re-energization of the motor until it has been braked to a virtual stop. The control circuit also includes a timing network operating to prevent continued pumping of the breaker operating mechanism by the motor operator should the operating mechanism for some reason fail to become charged within a prescribed time period.
Abstract: The present invention is a device for stopping a passenger conveyor.A stop pushbutton is depressed to deenergize a driving motor for an escalator and an operating winding for an electromagnetic brake. The electromagnetic brake has a mechanical braking means whose operations is opposed by the magnetic force of the operating winding. Then two timing relays are energized and also the brake operating winding is reenergized through a variable resistor to brake the motor with a low braking force. The timing relays are successively picked up after predetermined time intervals to increase the resistance of the resistor to increase the braking force stepwise by decreasing the current and hence the magnetic force of the operating winding. When the escalator reaches a predetermined low speed, the brake operating winding is again deenergized to apply the rated braking force to the motor until the escalator is stopped.