Abstract: An electric treadmill includes a motor and a motor driving circuit. The motor driving circuit is operable to control electric current flow from a positive electrode through the motor to a negative electrode to drive the motor. The motor driving circuit has a switch path connected between the positive electrode and the negative electrode. The switch path has a resistance element and a switch element connected in series. When the motor driving circuit receives power from the external power source, the switch element will automatically switch to an open state so that the resistance element is inactive; and when the motor driving circuit does not receive power from the external power source, the switch element will automatically switch to an closed state so that the resistance element is operated to provide a resistive load for stopping rotation of the endless belt.

Abstract: Embodiments of systems and methods for operating a power tailgate system involve a vehicle that includes a tailgate, a motor connected with the tailgate for interdependent movement, and a motor circuit for the motor. The embodiments include, upon the initiation of a driving event in the vehicle, identifying that the tailgate is unclosed. The embodiments further include, in response to identifying that the tailgate is unclosed, upon the initiation of the driving event, irrespective of whether the tailgate is moving or not moving, checking the tailgate against movement during the driving event, wherein checking the tailgate against movement includes operating the motor circuit to electrically brake the motor.

Abstract: A system in a vehicle includes a current regulator to obtain current commands from a controller based on a torque input and provide voltage commands and an inverter to use the voltage commands from the current regulator and direct current (DC) supplied by a battery to provide alternating current (AC). The system also includes an electric traction motor to provide drive power to a transmission of the vehicle based on injection of the AC from the inverter. The current regulator adjusts parameters of a transfer function implemented by the current regulator, based on feedback of an input to and an output from the electric traction motor to achieve the AC corresponding with the torque input in no more than two control cycles.

Abstract: A fan driving circuit includes a primary winding, an activating capacitor, a control circuit, a switch circuit and a secondary winding. The primary winding and the activating capacitor are electrically coupled to an external power source. The control circuit generates a control signal. The switch circuit is electrically coupled to the first winding. The switch circuit is also electrically coupled to the activating capacitor. The switch circuit has at least one control terminal electrically coupled to the control circuit for receiving the control signal. The secondary winding is electrically coupled to the switch circuit. The secondary winding is electrically coupled to the switch circuit. The secondary winding electromagnetically drives a fan according to a flowing direction of its driving current. The switch circuit conducts the secondary winding's driving current's flowing direction based on the control signal's voltage level.

Abstract: A current estimating device that estimates a capacitor current of a high-voltage circuit for driving a motor, wherein the current estimating device calculates a voltage utilization rate using the input voltage of an inverter included in the high-voltage circuit and the speed of the motor, calculates a first constant by applying the voltage utilization rate to a predetermined first arithmetic expression, and calculates the capacitor current of an electrical condenser included in the high-voltage circuit by multiplying the first constant by a motor current effective value.

Abstract: A method of recycling motor power of a movable object is provided to recycle and redistribute power from at least one motor in a decelerating state. The method comprises determining whether an operating state of at least one motor of the movable object is a decelerating state, and recycling power from the at least one motor having a decelerating state. The method also comprises redistributing the recycled power to other power consuming components of the movable object. The method of present invention increases the energy efficiency and a battery life of the movable object. The movable object may be an unmanned aerial vehicle (UAV).

Abstract: A method of recycling motor power of a movable object is provided to recycle and redistribute power from at least one motor in a decelerating state. The method comprises determining whether an operating state of at least one motor of the movable object is a decelerating state, and recycling power from the at least one motor having a decelerating state. The method also comprises redistributing the recycled power to other power consuming components of the movable object. The method of present invention increases the energy efficiency and a battery life of the movable object. The movable object may be an unmanned aerial vehicle (UAV).

Abstract: A vehicle control system, a surface marking for a surface upon which a vehicle can be positioned and a method of positioning a vehicle is provided. The vehicle control system is configured to position a vehicle. The vehicle comprises a mobile inductive charging point. The vehicle control system comprises one or more parking sensors configured to determine the position of the vehicle relative to a surface upon which the vehicle is positioned and/or obstacles around the vehicle. The one or more parking sensors are further configured to locate a visual indicator indicating the position of a fixed inductive charging point relative to the vehicle, and a parking assistance controller configured to automatically park the vehicle in a parking space on the surface based on data from the one or more parking sensors.

Abstract: A control device for a machine tool including a feed shaft motor for driving a feed shaft and a main shaft motor for driving a main shaft is provided with: a determination unit determining whether an operation of the feed shaft motor satisfies a predetermined determination condition; and an excitation command unit outputting an excitation current command to output excitation current larger than excitation current instructed by a master control unit to the main shaft motor, when the determination unit determines that the predetermined determination condition is satisfied.

Abstract: After satisfaction of an overrun condition that a tentative torque Tm1tmp of a motor overruns a torque limit Tlim1, a torque command Tm1* of the motor is set by limiting the tentative torque Tm1tmp with the torque limit Tlim1. With respect to an engine, the greater between a converted power Pesh and a value 0is set to a second correction power Pemo2. A requested power Pe* of the engine is recalculated by subtracting a first correction power Pemo1 and the second correction power Pemo2from the requested power Pe*. The engine is controlled using the recalculated requested power Pe*, while the motor is controlled using the torque command Tm1*.

Abstract: A method and apparatus are provided for securing an electric vehicle from unwanted movement when the electric vehicle is parked. The electric vehicle includes a drive wheel and an electric motor for driving the drive wheel. The method includes the steps of: (a) placing the electric vehicle in an electronic park brake mode; (b) automatically detecting that the electric vehicle is rolling from an initial position; and (c) automatically causing the electric motor to apply a reverse torque to the drive wheel to return the electric vehicle to the initial position or automatically causing the electric motor to lock the drive wheel to inhibit further movement of the electric vehicle.

Abstract: The system has a driving circuit for the motor of the electric fan, coupled to the electrical system of a motor vehicle and having a plurality of controlled electronic switches, and an electronic control unit arranged to control the driving circuit in such a way as to cause the flow in the motor of a variable average current capable of producing a required speed of rotation, in accordance with a predetermined relationship or function. The control unit is designed to store a predetermined threshold of rotation speed, and to control the motor through the associated driving circuit in such a way that when the rotational speed of the motor exceeds the threshold the driving circuit causes electrical braking of the motor.

Abstract: A control system for a thrust reverser with a movable cowl includes an electromechanical actuator to actuate the movable cowl, an electric drive unit (M) driving the actuator, and a power control unit capable of controlling the electric drive unit (M). The power control unit moves the movable cowl to a closed position and/or to a deployed position. In particular, the control system includes an electronic circuit for electric braking capable of braking the electric drive unit (M), in case of overspeed of the drive unit when the movable cowl is moved to the closed position and/or to the deployed position.

Abstract: An electric motor controller includes controller electronics configured to control an electric motor. The electric motor controller also includes a thermoelectric cooler in thermal communication with the controller electronics. The thermoelectric cooler is configured to receive a braking current associated with braking of the electric motor and provide cooling to the controller electronics.

Abstract: Methods and systems for starting an electric motor using a motor controller including a processor are provided. The method includes determining if the electric motor is operating, increasing a failed start counter if the electric motor is determined not to be operating, determining a reverse rotation by comparing a failed start counter to a predetermined threshold, and applying a reverse rotation start routine to the electric motor when a reverse rotation is determined.

Abstract: In hybrid construction machine employing a hydraulic motor and an electric motor for the driving of the swing structure, satisfactory operability of a combined operation of the swing structure and other actuators is secured irrespective of the operating status of the electric motor. A control device of the hybrid construction machine executes control selected from: hydraulic/electric complex swing control for driving the swing structure by total torque of the electric motor and the hydraulic motor when a swing operating lever device is operated; and hydraulic solo swing control for driving the swing structure by the torque of the hydraulic motor alone when the swing operating lever device is operated.

Abstract: A servo control device includes a follow-up control unit that controls a control target that drives a mechanical system by a motor, a command function unit that has input therein a phase signal ? indicating a phase of a cyclic operation performed by the control target, and that calculates a machine motion command according to the phase signal ? by a preset first function, a second derivative unit that uses a second function obtained by second-order differentiating the first function with respect to the phase signal to calculate a value of the second function according to the phase signal as a second-order differential base signal, a correction-value computation unit that computes a first command correction value for correcting the motor motion command by using a product of a square value of the phase velocity, the second-order differential base signal, and a first constant, and a correction-value addition unit that calculates the motor motion command based on an added value of the first command correction val

Abstract: A method of operating an electrical machine having first and second phase windings. The method includes: (1) applying positive first current to the first phase winding while the first phase winding's back electromotive force (emf) is positive; (2) applying negative second current to the first phase winding while the first phase winding's back emf is negative; and (3) applying positive third current to the second phase winding while the second phase winding's back emf is positive. The first current is conducted through a circuit composed of a battery, the first phase winding, and a first switch. The second current is conducted through a circuit composed of a first capacitive storage element, the battery, the first phase winding, and a second switch, and the third current is conducted through a circuit composed of the battery, the second phase winding, and a third switch.

Abstract: In a method and a device for pulse width modulated (PWM-) activation of an electrical drive motor (2) of an adjustment arrangement based on a reference of the mechanical system of the adjustment arrangement that corresponds to a relationship between the force (F) on the drive motor (2) and the adjustment path (s) or the adjustment time (t) of the adjustment arrangement stored in a memory (9), an anticipated future force value (F(t+t0)) is determined based on the reference of the mechanical system in order to adjust the PWM activation in advance by utilizing this future force value such that motor synchronization fluctuations can be prevented upon anticipated mechanical fluctuations in the adjustment arrangement.

Abstract: An electric switch for an electric tool with an electric motor. The switch has first electrical terminals for electrical connection to a voltage supply and second electrical terminals for electrical connection to the electric motor. The switch has an actuating mechanism which can be adjusted between an initial position and a final position, wherein the electric motor is switched off when the actuating mechanism is located in the initial position and is switched on when the actuating mechanism is not located in the initial position. The switch also has a braking circuit for braking the electric motor, the braking circuit operating when the actuating mechanism is reset to the initial position. The switch also has a reversal circuit for switching over the direction of rotation of the electric motor. The braking circuit is arranged between the second electrical terminals and the reversal circuit.

Abstract: A touch control arrangement is arranged for a container having a foldable cover being folded between an opened position and a closed position via an actuation unit. The touch control arrangement includes a power source and a touch actuator electrically linked to the power source, wherein the touch actuator is located out of the storage cavity of the container body and is arranged in such a manner that when the touch actuator is activated by a presence of a touch, the actuation unit is actuated to move the foldable cover from the closed position to the opened position.

Abstract: In a torque motor driving device for wire cut electrical discharge machines, a voltage waveform rectified by a full-wave rectifying circuit, not using a high-capacitance electrolytic capacitor, is applied as an AC voltage to a single-phase torque motor by a bridge circuit including semiconductor switches. A PWM signal whose duty is adjusted so that the current flowing through the torque motor matches an instructed value is generated and the generated PWM signal is used for the operation of the bridge circuit.

Abstract: There is provided a slewing control device that enables to detect breakdown of a driving system of a mechanical brake, and generate a torque for holding a slewing body in a stopped state to thereby prevent movement of the slewing body when an anomaly has occurred. In a working machine for driving a slewing body by an electric motor 1, judgment is made as to whether a mechanical brake 4 is in an inconsistent state, based on a command to be outputted to a brake circuit B, and a pressure detected by a brake pressure sensor 17. The inconsistent state is a state that the mechanical brake 4 is in a brake released state when an activation command for switching the mechanical brake 4 to a brake activated state is outputted. If it is judged that the mechanical brake 4 is in the inconsistent state, a command for obtaining a braking torque for holding the slewing body in a stopped state is outputted to the electric motor 1.

Abstract: A servomotor control system includes: an integrated control unit for integrally controlling servomotors; and servomotor units coupled with the integrated control unit and the servomotors. Each servomotor unit includes: a motor driver; a rotation detector of the servomotor; an original point detector for detecting an original point of the servomotor; a communication element for obtaining control information including rotation position instruction information from the integrated control unit; a rotation position calculator for calculating a current rotation position of the servomotor based on a rotation detection signal; a motor drive instruction element for outputting driving instruction information to the motor driver according to the control information and the current rotation position; and a current rotation position correction element for resetting the current rotation position to a predetermined original point when the original point detector detects the original point.

Abstract: A circuit for controlling a rotation speed of a fan of an electronic device according to a temperature of the electronic device. The circuit senses the temperature of the electronic device, and outputs a voltage changing with the sensed temperature. The rotation speed of the fan changes with the voltage. The circuit slows the rotation speed of the fan down when the sensed temperature of the electronic device is decreased.

Abstract: The system has a driving circuit for the motor of the electric fan, coupled to the electrical system of a motor vehicle and having a plurality of controlled electronic switches, and an electronic control unit arranged to control the driving circuit in such a way as to cause the flow in the motor of a variable average current capable of producing a required speed of rotation, in accordance with a predetermined relationship or function. The control unit is designed to store a predetermined threshold of rotation speed, and to control the motor through the associated driving circuit in such a way that when the rotational speed of the motor exceeds the threshold the driving circuit causes electrical braking of the motor.

Abstract: Tubular linear piezoelectric motor (100, 300), and a method for exciting a tubular piezoelectric resonator (101, 301) used in such motor. The motor is comprised of a resonator (101, 301) formed of a cylindrical tube. The tube has length nL comprised of a piezoelectric material, where L is some length, and n is an even numbered integer, greater than zero. The piezoelectric material of the cylindrical tube is polarized in a radial direction, perpendicular at each point to the interior and exterior surface of the cylindrical tube. The resonator is excited with one signal having a single exciter frequency applied across an inner electrode (102, 302) and one or more first outer electrodes (103, 103a, 103b). The single exciter frequency is selected to move a contact site of one or more annular protrusions along an elliptical path when the resonator is excited.

Abstract: A damper system for a vehicle including an electromagnetic damper, wherein the electromagnetic damper includes: (i) an electromagnetic motor; (ii) a motion converting mechanism; and (iii) an external circuit including (A) a first connection passage, (B) a second connection passage, (C) a first-connection-passage-current adjuster, and (D) a second-connection-passage-current adjuster, wherein the damper system comprises an external-circuit controller including: (a) a main-adjuster control portion configured to perform, on one of the first-connection-passage-current adjuster and the second-connection-passage-current adjuster that is designated as a main adjuster, a first control for mainly damping the relative vibration of the sprung portion and the unsprung portion; and (b) an auxiliary-adjuster control portion configured to perform, on one of the first-connection-passage-current adjuster and the second-connection-passage-current adjuster that is designated as an auxiliary adjuster, a second control for assisti

Abstract: There is provided a slewing control device that enables to detect breakdown of a driving system of a mechanical brake, and generate a torque for holding a slewing body in a stopped state to thereby prevent movement of the slewing body when an anomaly has occurred. In a working machine for driving a slewing body by an electric motor 1, judgment is made as to whether a mechanical brake 4 is in an inconsistent state, based on a command to be outputted to a brake circuit B, and a pressure detected by a brake pressure sensor 17. The inconsistent state is a state that the mechanical brake 4 is in a brake released state when an activation command for switching the mechanical brake 4 to a brake activated state is outputted. If it is judged that the mechanical brake 4 is in the inconsistent state, a command for obtaining a braking torque for holding the slewing body in a stopped state is outputted to the electric motor 1.

Abstract: An electromagnetic braking system and method is provided for selectively braking a motor using an electromagnetic brake having an electromagnet, a permanent magnet, a rotor assembly, and a brake pad. The brake assembly applies when the electromagnet is de-energized and releases when the electromagnet is energized. When applied the permanent magnet moves the brake pad into frictional engagement with a housing, and when released the electromagnet cancels the flux of the permanent magnet to allow a leaf spring to move the brake pad away from the housing. A controller has a DC/DC converter for converting a main bus voltage to a lower braking voltage based on certain parameters. The converter utilizes pulse-width modulation (PWM) to regulate the braking voltage. A calibrated gap is defined between the brake pad and permanent magnet when the brake assembly is released, and may be dynamically modified via the controller.

Abstract: A hoist system with an overspeed detection sub-system for detecting overspeed by comparing an actual drum assembly speed with a target value. For example, the rotation of a motor may be determined by a first rotary encoder and the rotation of a drum may be determined by a second rotary encoder. The output of the first rotary encoder (the basis of a target value) is compared with the output of the second rotary encoder (corresponding to actual motion of the drum). If the difference between the target value and the actual motion is too large, then a problem, such as a broken hoist hardware component may exist, and appropriate remedial action is taken, such as braking the motor and/or the drum.

Abstract: A powered apparatus includes a driven component that is movable along a path and a drive motor that moves the driven component along the path. A motor speed detector monitors an instantaneous speed of the drive motor at each position along the path. An electronic control unit operates the drive motor and includes load profile data representing a number of motor loads associated with respective positions of the driven component along the path. A calculating component determines a calculated final rest position of the driven component by adding a current position of the driven component along the path and an adjustment coefficient representing an additional distance of travel along the path based on the instantaneous speed of the drive motor and a respective motor load associated with the additional distance of travel. A non-volatile memory component stores the calculated final rest position of the driven component.

Abstract: Embodiments of the invention provide a control system for a garage door. The control system can include a motor, a pulley, a synchronous drive member, a carriage, and an operator. The pulley can be coupled to and driven by the motor. The synchronous drive member can be coupled to the pulley and driven by the pulley. The carriage can be coupled to the synchronous drive member and to a bottom edge of a garage door. The operator can be coupled to the motor and can control the motor. The operator can be mounted vertically adjacent to the garage door when the garage door is in a closed position.

Abstract: A fluid-operated medical or dental handle with a device for limiting the rotational speed to a maximum rotational speed value is disclosed. The handle comprises a rotating part that can be induced to rotation by a driving fluid for driving a tool connectable to the rotating part, an electrodynamic transducer driven by the rotating part for induction of an electric voltage, wherein the electrodynamic transducer has at least one coil and a magnetic element and at least one switch element for optional opening and closing of a circuit between the two ends of the at least one coil, so that with the circuit closed, an electric current and an induced magnetic field that decelerates the rotational speed of the rotating part and the tool connectable thereto can be induced in the coil of the electrodynamic transducer.

Abstract: Disclosed is a method for identifying pinching situations in a motor-driven displacing device. During a displacing process along an actuating direction, values (W(n) to (W(n?m)) of a quantity (1), which characterizes the currently occurring displacing force, or a quantity derived therefrom are determined and stored, and a quantity (8) that characterizes the pinching force of the displacing device is determined on the basis of at least two stored values (W(n) to (W(n?m)).

Abstract: An electric motor for a textile machine can be operated as a generator if the supply voltage fails. The electric motor comprises a rotor configured as the motor armature and a motor phase control circuit comprising a plurality of semiconductor components wherein the electric motor can be short-circuited if a predeterminable limit value is passed during generator operation. The motor circuit causes the short-circuiting on passing the limit value by activating one or more of the semiconductor components. The multi-phase electric motor is used as the single drive of a rotor of the textile machine. wherein the semiconductor components of the phase control bridge. on passing a predeterminable limit value, contactlessly short-circuit the electric motor to brake the electric motor.

Abstract: A device for finding a home position of a moveable member includes a magnet mounted on the moveable member and two switch-type Hall effect detectors, one on each side of the home position and equally spaced from the home position. The device includes a device for measuring movement of the moveable member and a microprocessor with a memory that receives information from the two Hall effect detectors and the device for measuring movement.

Abstract: The present invention discloses a method of servo controlling an electric motor during its start-up, comprising at least one step of measuring the speed after a determined duration counting from the commencement of start-up. During a first start-up, the servo control system determines the deviation between the value of the measured speed and a preset value. During a second start-up, the servo control system modifies at least one duration parameter of the commands applied to the motor as a function of the deviation determined during the first start-up, so as to reduce this deviation in the course of this second step. Advantageously, the start-up comprises three phases making it possible to start the motor while avoiding making it too noisy. The invention also relates to an apparatus implementing the method.

Abstract: An anti-pinch control system is used to identify obstructions in a path of movement for a powered vehicle member, such as a vehicle window for example. A pinching area is identified for the vehicle window and at least one indicium or indicator is mounted to a vehicle structure to be in view of a camera. The indicium is positioned such that no object may pass into the pinching area without also passing between the camera and at least a portion of the indicium. The camera identifies an obstruction when any portion of the indicium is obscured. This indicium includes a plurality of predefined zones, with each zone being associated with an operational function, such as upward window movement, downward window movement, door locking, side mirror movement, etc. This eliminates the need for separate switches to perform each of these functions thereby reducing overall cost for a vehicle door system.

Abstract: A visual indication for a motor controlled shaft, especially useful for retrofitting hand controlled printing presses.

Abstract: An electrical control safety system is provided comprising two photocells or equivalent sensors applied on a sliding gate, the two photocell systems being composed respectively of at least two transmitters and two receivers, and the control safety system being cyclically able to make the first photocell system operate during a first operating time interval while the second photocell system is disabled, and being cyclically able to make the second photocell system operate, during a second operating time interval, subsequent to the first time interval, while the first photocell system is disabled.

Abstract: A bi-directional sensing edge includes a mounting member for securing the sensing edge to a leading member of a gate. An elongate outer sheath has at least first and second portions each respectively corresponding to first and second sides of the leading member. An interior surface of the sheath is spaced from an outer surface of the mounting member to thereby define a second area. A first switch is complementarily positioned within the second area and corresponds to the first portion of the sheath for actuation of the first switch upon application of pressure on an exterior surface of the sheath substantially anywhere along the first portion. A second switch is complementarily positioned within the second area and corresponds to the second portion of the sheath for actuation of the second switch upon application of pressure on the exterior surface of the sheath substantially anywhere along the second portion.

Abstract: A method and apparatus for stopping an AC motor that is controlling a load while detecting mechanical brake slippage of a mechanical brake for holding the load against movement includes a controller for decreasing torque-producing current commands from the drive while a speed regulator is commanding zero speed, sensing movement of the load while the speed regulator is commanding zero speed, detecting movement of the load past a pre-determined distance limit, and increasing torque to support the load and prevent further movement of the load. The controller will again decrease torque-producing current commands from the drive, and again checking for movement of the load, and upon sensing no load movement upon reaching zero torque, then shutting off the motor.

Abstract: A controller writes position information (count value) of the window glass into an EEPROM based on halting of operation of a drive motor and identifies the current position of the window glass based on the position information of the window glass written in the EEPROM at the start of power supply. The controller determines whether the current position of the window glass has been lost or not at the start of power supply. Only when the controller determines that the current position of the window glass has been lost at the start of power supply, the controller shifts to a mode of performing relearning of the origin position for matching the position of the window glass with the position of the window glass corresponding to the position information written into the EEPROM.

Abstract: A system for operating a barrier system such as a garage door, gate or fence. A DC motor is connected to and operates a barrier drive. A power amplifier is configured to receive power signals from a power supply and to output modulated DC signals to the DC motor. A controller implements an intelligent closed-loop motion control algorithm to control the power amplifier according to a non-linear motion profile. A feedback sensor provides status signals to the controller to determine position or speed of the barrier.

Abstract: A motor and a rotary potentiometer, or other position sensor, running on the motor shaft are mounted in a first enclosure with an output shaft for driving a power switch open or closed. A part of the system outside the first enclosure makes use of a motor position signal from the rotary potentiometer that is processed by a microcontroller that a worker can interact with at a switch panel to set and adjust motor travel limits without needing access into the motor enclosure. The first enclosure and its components can be used for various applications, including those for either underground or pad-mounted switches, which for the latter case can have the first enclosure inside a second enclosure on a pad, and the second enclosure also contains other power and control elements of the system. A portable unit with the switch panel for travel limits can be provided.

Abstract: A vehicle driving force control apparatus is configured to prevent co-rotation of the motor caused by rotation of a pair of wheels when a clutch connecting the wheels and the motor is released (disconnected). When the clutch is released, the motor is braked by short circuiting the armature. The motor is then braked again by setting the field current of the motor to 0 when the rotational speed of the motor reaches 0. After the clutch is released, a braking-direction field current is applied to the motor in accordance with the decreasing rotational speed of the motor such that the braking force is decreased as the rotational speed of the motor decreases.

Abstract: A control unit for a moveable barrier, such as a garage door, includes a microcontroller connected to a motor speed detector, motor current sensor or a sensor for determining forces exerted on or by the barrier. A user interface includes user actuatable switches for setting a first maximum force value to be exerted on or by the barrier when moving in one direction and the microcontroller automatically sets the value of a second maximum force to be exerted on or by the barrier when moving in the opposite direction. The second force value may be based on the force value set by the user or the second force value may be a preset value. Both force limits may be automatically set as a function of a maximum force exerted on said barrier during movement thereof, during a force learning operation.

Abstract: The invention concerns a method for controlling an electric motor driving a body in translation between an initial position and a final position determined by a stop, by powering the motor with reduced voltage in the final position approach phase. The motor has a torque/speed characteristic such that the torque at null speed decreases with the supply voltage. As the approach phase starts, the method consists in determining a reduced voltage by decreasing the rotational speed of the motor from a nominal value to a predetermined reduced value and in cutting the motor power supply if the motor rotational speed drops below a predetermined threshold value.

Abstract: A control device and a method of stopping the spindle motor or an optical disc system. The control device primarily includes an optical disc control chip, a motor driving circuit and a spindle motor. The optical disc control chip generates and delivers a spindle motor control signal to the motor driving circuit for driving the spindle motor into rotation. During a first period, the spindle motor control signal level is controlled to produce the largest reversing torque permitted by the spindle motor for braking purpose. During a second period, the spindle motor control signal level decreases gradually to approach to a lock level that is smaller than that for actuating the spindle motor, so that the reversing torque is also decreasing gradually.