Abstract: A controller in a motor control device includes an integral operation unit 606A (608A) that performs an arithmetic operation for a d(q)-axis integrated value Id** (Iq**) through integral control performed on a d(q)-axis current deviation ?Id (?Iq) and is configured to perform an arithmetic operation for a d(q)-axis voltage command value for controlling an output voltage of an inverter of a three-phase brushless motor. The controller further includes a limit value arithmetic operation unit 606C (608C) that performs an arithmetic operation for d(q)-axis integration upper and lower limit values Idmax (Iqmax) and Idmin (Iqmin) on the basis of a power source voltage of the inverter and the like and an integration limiting unit 606D (608E) that limits Id** (Iq**) within a predetermined range defined by the d(q)-axis integration upper and lower limit values.

Abstract: A machine learning device of a machining condition adjustment device includes: a state observation unit that observes each of machining condition data indicative of a machining condition of each used tool and cycle time data indicative of a cycle time of one machining, as a state variable; a determination data acquisition unit that acquires determination data indicative of a result of an appropriateness determination of one machining in the case where an adjustment of the machining condition is performed; and a learning unit that performs learning by associating the machining condition data and the cycle time data with the adjustment of the machining condition using the state variable and the determination data so as to enables effective use of the allowance of a cycle time.

Abstract: Disclosed are a method and a system for feedback-controlling including controlling a current supply unit in a controller so that an output applied to a driving unit from the current supply unit is repeatedly turned on/off by predetermined period and duty. The method also includes feedback-controlling of an output value of the controller applied to the current supply unit from the controller so that the output of the current supply unit follows a target value. The feedback-controlling includes an integration control process and stops the integration control process in the period that the current supply unit turns off the output thereof.

Abstract: The subject of the invention is to easily detect whether the dust collection amount is full. The present invention provide a charging-type electric vacuum cleaner comprising: a ventilator for suctioning air containing dust through a suction port; a motor for driving the ventilator; a dust collection section for filtering the suctioned air and capturing the dust; a storage battery; a switching element for connecting the storage battery to the motor; a current detecting section for detecting an electric current Ia flowing to the motor; a warning section for warning when a dust collection amount in a dust collection section is full; and a control section for operating the switching element to drive the motor, and for detecting a terminal voltage Vb of the storage battery and the electric current Ia to operate the warning section when Vb?V1 and Ia?I1 (V1 and I1 are preset values) are established.

Abstract: A method for controlling the operation of an arrangement of at least two electric machines coupled to different wheels of a motor vehicle and connected to a battery which provides an actual minimum and maximum limiting current for the electric machines. Desired torques are provided for the electric machines by a drive control logic. A desired current resulting from the desired torque is ascertained for each electric machine, and the sum of the desired currents are compared with the maximum and minimum limiting current. If the sum lies outside an interval defined by the limiting currents, the desired currents are adjusted using at least one change rule such that the sum of the desired currents lies within the interval. Adjusted desired torques are determined from the adjusted desired currents and used to control the electric machines.

Abstract: Provided are a motor controller for suppressing a torque pulsation with a simple configuration and obtaining a sufficient output torque in the case of an open-type fault occurring in any one of windings of a motor and inverters, and an electric power steering device using the motor controller. In the motor controller for controlling a current supplied from and a voltage applied from a power source with respect to the motor including winding sets of a plurality of systems, when a fault determination unit (31) determines the occurrence of the open-type fault, the supply of the currents to the windings of one of the systems in which the fault has occurred is stopped by control performed on switching elements included in the inverter of the faulty system, whereas the supply of the currents to the windings of the normal system in which the fault has not occurred is continued.

Abstract: A control device performs voltage conversion control on a voltage conversion circuit between a power supply and motor control circuits which control a plurality of motors. The control device includes sampling units for sampling a DC voltage after voltage conversion, target voltage setting units for setting target voltages VHT1 and VHT2 of the plurality of motors, selection unit for selecting a target voltage VHT to be converted by the voltage conversion circuit from a plurality of target voltages VHT1 and VHT2, generating unit for generating a sampling timing TS on the basis of a gate signal GS1 or GS2 of one of the motors with the target voltage which has not been selected, and control unit for performing the voltage conversion control using the DC voltage sampled by the sampling units at the sampling timing TS in response to each sampling timing request DS in the voltage conversion control.

Abstract: This disclosure discloses a motor control apparatus including a controller. The controller includes a position controller and a speed controller. The controller is configured to control the inverter on the basis of the torque command. The controller includes a torque limiter configured to start first torque limitation which limits a commanded torque based on the torque command to a first torque or less in a case where the voltage detector detects that the DC voltage falls below a predetermined voltage, and to cancel the first torque limitation in a case where the voltage detector detects that the DC voltage exceeds the predetermined voltage. The controller includes a speed limiter configured to limit a commanded speed based on the speed command to a first speed or less in a case where the torque limiter cancels the first torque limitation.

Abstract: A pulse motor driving circuit for driving a pulse motor includes a first switch having a terminal that is connected with a positive terminal of a power source; a second switch having a terminal that is connected with a negative terminal of the power source; and a capacitor having a terminal connected with a limit element and having another terminal connected with another terminal of the first switch and another terminal of the second switch, wherein the limit element is provided between the positive terminal and the capacitor and limits a current, wherein the first switch is turned on and the second switch is turned off in a current application start period while the current starts to be applied, wherein the first switch is turned off and the second switch is turned on in a period other than the current application start period.

Abstract: A motor control device comprises: a motor control unit that controls a motor; and a signal output unit that outputs a signal according to rotation of the motor, wherein the motor control unit controls the motor based on an output signal of the signal output unit so that a driven object driven by the motor is displaced to a target stop position. The motor control unit is configured to function as: a first control unit that estimates a upper current limit and controls the motor according to the upper current limit; a second control unit that controls motor according to an operated amount of at least one of the motor or the driven object; a switching unit that switches between the first control unit and the second control unit; a first calculating unit that calculates an amount necessary for stop; and a second calculating unit.

Abstract: A method controls an operation of an actuator. A first control signal is determined to change a position of a moving element of the actuator according to a trajectory of the moving element. A second control signal is determined to compensate for a first component of an error of the operation due to uncertainty of a model of the actuator. A third control signal is determined to compensate for a second component of the error of the operation due to an external disturbance on the actuator. The operation of the actuator is controlled based on a combination of the first control signal, the second control signal, and the third control signal.

Abstract: An electric chain saw has an electric drive motor defining a motor-specific characteristic line of the drawn-in current as a function of the rotational speed of the motor. A control unit controls the current flowing through the drive motor below an engaging rotational speed to values below the motor-specific characteristic line. In order to generate an operating point the operator can feel in a working region in a predetermined rotational speed band, a control characteristic line of the electric input power of the electric drive motor as a function of the rotational speed is provided above the engaging rotational speed. The control characteristic line is adapted to reduce the electric input power within the rotational speed band to an approximately even mean power so as to cause the torque of the drive motor to increase within the rotational speed band with falling rotational speed.

Abstract: Provided is an apparatus for operating interior permanent magnet synchronous motor in a system including a detector measuring a position and a speed of a rotor of an IPMSM, the apparatus including an output unit generating and outputting a current command driving a MTPA (Maximum Torque Per Ampere) based on the command torque, a correction unit correcting the current command outputted by the output unit, a feedback unit transmitting over-modulated voltage information to the correction unit, a control unit controlling the current command to output a voltage, a first limit unit limiting an output of the control unit using a maximum voltage synthesizable by an inverter unit, and the inverter unit applying a 3-phase voltage command for tracking a command torque to the IPMSM using an output of the first limit unit.

Abstract: A motor control device comprises: a motor control unit that controls a motor; and a signal output unit that outputs a signal according to rotation of the motor, wherein the motor control unit controls the motor based on an output signal of the signal output unit so that a driven object driven by the motor is displaced to a target stop position. The motor control unit is configured to function as: a first control unit that estimates a upper current limit and controls the motor according to the upper current limit; a second control unit that controls motor according to an operated amount of at least one of the motor or the driven object; a switching unit that switches between the first control unit and the second control unit; a first calculating unit that calculates an amount necessary for stop; and a second calculating unit.

Abstract: A motor control device comprises: a motor control unit; and a signal output unit, wherein the motor control unit controls a motor based on an output signal of the signal output unit, wherein the motor control unit is configured to function as: a first control unit performs a first motor control, in which a current upper limit is estimated based on a rotation speed of the motor and is input to the motor, a second control unit performs a second motor control, in which a second driving current, which is a driving current lower than the first driving current at the end of the first motor control is input, a third control unit performs a third motor control, in which a third driving current to be input to the motor is determined, and a switching unit that sequentially switches the first, second, and third control units.

Abstract: A voltage detection section and current detection section detect a voltage and current supplied to a motor, and the detected voltage and current are supplied to a position detection section. An angular speed output from the position detection section is supplied to a differentiator to output an angular acceleration. A fundamental wave component extraction section extracts a fundamental wave component of the angular acceleration, and the extracted fundamental wave component is supplied to an amplitude adjustment section. The output of the amplitude adjustment section is subtracted from the average current command by a subtraction section. This subtraction result, current detection value, and the rotor position from the position detection section are supplied to a current control section to carry out the current control operation so as to obtain a current command.

Abstract: A voltage detection section and current detection section detect a voltage and current supplied to a motor, and the detected voltage and current are supplied to a position detection section. An angular speed output from the position detection section is supplied to a differentiator to output an angular acceleration. A fundamental wave component extraction section extracts a fundamental wave component of the angular acceleration, and the extracted fundamental wave component is supplied to an amplitude adjustment section. The output of the amplitude adjustment section is subtracted from the average current command by a subtraction section. This subtraction result, current detection value, and the rotor position from the position detection section are supplied to a current control section to carry out the current control operation so as to obtain a current command.

Abstract: A method for decelerating a motor in a computer numerical controlled machine tool is provided. The method includes calculating a present rate of deceleration DP, for a motor of a motor drive system, based on a present speed SP of the motor, a reference speed SR of the motor, and a reference rate of deceleration DR of the motor. The method also includes decelerating the motor from SP according to DP. The motor drive system comprises a maximum power rating that defines a maximum power, generated by the motor while decelerating, that can be dissipated without overloading the motor drive system. DR is a rate of deceleration such that power, generated by the motor while decelerating from SR according to DR, is equal to the maximum power rating. Power, generated while decelerating the motor from SP according to DP, is equal to or less than the maximum power rating.

Abstract: A control device for a machine tool including a feed axis driving motor; a first power consumption calculating portion calculating power consumption of the feed axis driving motor; a second power consumption calculating portion calculating power consumption of equipment adapted to be operated by constant power; and a motor control portion determining a target time constant correlated with at least one of acceleration time and deceleration time of the feed axis driving motor, based on a summation of the power consumption calculated by the first power consumption calculating portion and the power consumption calculated by the second power consumption calculating portion, and controlling the feed axis driving motor based on the target time constant.

Abstract: A motor protection device includes a detection unit for detecting an operating state of a motor and outputting a detection signal; a reference unit for generating a variable reference signal; a discriminating unit for comparing the detection signal with the variable reference signal to discriminate whether the motor is in an abnormal condition; and a protection unit that receives a result of discrimination from the discriminating unit and limits a driving current for the motor when the motor is in an abnormal condition. The motor protection device is characterized in that the reference unit adjusts the variable reference signal according to a motor rotation detection signal, so that the motor rotation detection signal and the detection signal are used synchronously in discriminating whether the motor is in an abnormal condition, and the motor in an abnormal condition may be doubly protected.

Abstract: The non-linear elastic deformation component included in the angular transmission error of an actuator provided with a wave gear drive is a component of the angular transmission error occurring due to elastic deformation of a flexible externally-toothed gear when the direction of rotation of the motor shaft changes. This component can be analyzed by driving the motor in a sine-wave shape. A model of the non-linear elastic deformation component (non-linear model) obtained from the analysis results is used to store data or a function for compensating for this component in a motor-control device. Compensation for the non-linear elastic deformation component (?Hys) is added to a motor-shaft angle command (?*M) as a compensation input (N?*TE) for feed-forward compensation. As a result, the non-linear elastic deformation component (?Hys) can be effectively reduced, and the positioning precision of the actuator can be improved.

Abstract: A drive system for controllably driving an electric actuator includes a current sensor system to sense a current conducted by the actuator and a driver to electrically drive the actuator based on an output signal of the current sensor system. The current sensor system includes at least a first and a second %forwardcurrent sensor that have a mutually different sensitivity for the current to be sensed and the drive system includes a current sensor controller to control an extent to which each of the current sensors to determine the output signal of the current sensor system.

Abstract: Embodiments of the invention provide a method of detecting a fault condition in a motor of a pump. The method includes sensing a first current value and a speed of the motor, attempting a recovery operation if the first current value is greater than a current threshold and if the speed of the motor is less than a motor speed low threshold, and sensing a second current value during the recovery operation and shutting down a drive to the motor if the second current value is also greater than the current threshold. The method also includes performing the recovery operation for a time period if the second current value is less than the current threshold and attempting to operate the motor in a normal mode after the time period has elapsed.

Abstract: A control device for a machine tool including a feed axis driving motor; a first power consumption calculating portion calculating power consumption of the feed axis driving motor; a second power consumption calculating portion calculating power consumption of equipment adapted to be operated by constant power; and a motor control portion determining a target time constant correlated with at least one of acceleration time and deceleration time of the feed axis driving motor, based on a summation of the power consumption calculated by the first power consumption calculating portion and the power consumption calculated by the second power consumption calculating portion, and controlling the feed axis driving motor based on the target time constant.

Abstract: A circuit arrangement and a method for adjusting the power consumption of a load of a cooling fan motor of a motor vehicle that can be operated by a direct-voltage system has at least one semiconductor switch in the supply current circuit of the load, and a control unit for triggering the semiconductor switch or switches. The load is connectable via at least one sense field-effect transistor to the direct-voltage system the measurement output of the sense FET is connected to the control unit, and the control unit furnishes a signal corresponding to the current consumption of the load at the respective operating point.

Abstract: A synchronous motor control device having an optimal protection function in accordance with an operational state of a motor is provided.

Abstract: For ensuring high-precision control of a planar motor (1) comprising a magnet (2) and j coils (3), j=1 . . . N, wherein currents T7 can flow through the coils (3) such that a force and a moment are generated that interact with the magnet (2), it has been proposed to determine force and moment needed to change the relative position of magnet (2) and coils from a present position to a desired position, and then to determine the currents T7 necessary for generating this force and moment in the computing means (43) of the control unit (4) of the electric motor (1). The coil currents are then regulated accordingly with regulating means (44). The relative position of magnet (2) and coils (3) is measured with measuring means (5) and fed into the first input means (41) of the control unit (4).

Abstract: A motor control system which can realize current detection with high accuracy by using an amplifier having an ordinary level of accuracy and can avoid deterioration of current detection accuracy even when emperature is changed.

Abstract: A method of controlling the speed and position of a motor includes receiving a pulse train indicative of the speed of the motor, and a periodic signal at a frequency greater than the pulse train. The number of cycles of the periodic signal per cycle of the pulse train is counted, and compared to a predetermined number. The speed of the motor is adjusted to match the count to the predetermined number, thus effecting speed control. A command position signal defining a plurality of sampling points is generated. The number of cycles of the periodic signal between a sampling point of the command position signal and an operative edge of the pulse train is counted and compared to a predetermined number. The speed of the motor is further adjusted to match the count to the predetermined number, thus effecting position control.

Abstract: For controlling a traction motor of a vehicle, a current command value is determined based on a torque command and a load value representative of running load of the vehicle. A voltage command value is calculated in such a manner that a difference between the current command value and the actual current of the motor is converged to zero. An allowable range is determined for the voltage command value based on the load value and physical quantity associated with an operating condition of the motor. The voltage command value is compared with the lower and upper limits of the allowable range. A safeguard is set on the voltage command value when the latter is becoming smaller than the lower limit or greater than the upper limit. Preferably, the current command value is scaled down or scaled up depending on the voltage command value relative to the allowable range.

Abstract: A system controls an induction motor driven by a power inverter circuit. An operational amplifier circuit is operatively connected to the power inverter circuit and operative therewith for sensing DC current and controlling acceleration and deceleration of the induction motor. The operational amplifier circuit includes a first operational amplifier operative in a motoring mode to have a positive polarity output and remain substantially at zero during a regeneration mode. A second operational amplifier circuit is operative in a regeneration mode to have a negative polarity output and remain substantially at zero in a motoring mode.

Abstract: An object is to provide an inverter device capable of realizing exact protection of the winding of a motor. An inverter device for generating a pseudo alternating current by switching a direct current to drive a motor, comprises a controller that executes vector control on the basis of a secondary current applied to the motor. The controller calculates a current density from the secondary current to execute a predetermined protection operation on the basis of the calculated current density. The controller imposes a restriction on the operation frequency of the motor on the basis of the current density.

Abstract: An electronic control unit for producing a sufficiently boosted voltage even when a supply voltage becomes high includes an inverter that drives switching elements and converts a DC voltage into an AC voltage, and booster means which boosts a DC voltage that is input into a voltage to lie within a voltage range in which a voltage necessary for driving the switching elements is a lower-limit value and a maximum boosted voltage is an upper-limit value, and outputs the boosted voltage to the inverter.

Abstract: A control apparatus controls retraction of a device carried on a moveable member actuated by an electric motor. The control apparatus includes a measuring circuit with an output during a measuring phase including a back electromotive force (back EMF) from the electric motor plus a measuring circuit offset voltage. The control apparatus also includes an offset removing circuit connected to the output of the measuring circuit. The back EMF from the electric motor is provided at the output of the offset removing circuit. A driver circuit is connected to terminals of the electric motor for providing the electric motor with a drive current during a driving phase with a magnitude based on the back EMF from the electric motor.

Abstract: A translatory actuator unit including a translatory actuator module that moves an object straightly, a force sensor that detects a load applied to the translatory actuator module, and a servo control module that controls a speed, a position and/or output power of the translatory actuator module. The translatory actuator module, the force sensor and the servo control module are integrally configured. The servo control module has a two-way network means of receiving a control command concerning the speed, the position and/or the output power from a network, and transmitting information of the speed, the position and/or the output power to the network, a control means of controlling the speed, the position and/or the output power, and a self-diagnosis means of confirming safety and detecting an abnormal state based on detected information of the speed, the position, the load, and/or an electric current of the translatory actuator module.

Abstract: The invention relates to a fan arrangement comprising a radial or diagonal fan (370) with which a direct current motor (32) is associated as drive motor, further comprising a digital control element (23, 24) such as a microcontroller or microprocessor, associated with that direct current motor (32), and comprising a program, associated with that digital control element (23, 24), for controlling the current flowing through the direct current motor (32), which program is embodied to generate a substantially constant current in the motor (32) in the working rotation speed range of the fan.

Abstract: For applying a driving current to a motor, an H-bridge circuit is constructed by a first and a second switching unit and a first and a second linear unit. An error amplifier generates an error signal representative of a difference between the driving current detected by a current detecting circuit and a command current signal. A state control circuit synchronously controls the first and second switching units and a feedback circuit. Through the feedback circuit, the error signal is selectively applied to the first or second linear unit such that one is operated in a linear mode and the other is operated in a nonconductive mode, thereby controlling the driving current to become proportional to the command current signal. The state control circuit further controls a brake circuit for transforming the error signal into a brake signal to operate the first and second linear units simultaneously in a conductive mode.

Abstract: A motor drive circuit and method with frequency setting and correcting functions. The drive circuit includes a speed control device, which simultaneously receives a sense signal and a rotation frequency signal. A pulse width modulation signal capable of modulating a duty ratio may be generated by a pulse width modulation method. The pulse width modulation signal is then transferred to a drive timing controller that generates a timing control signal to control output timing of a power drive signal for the drive circuit. Meanwhile, a sensor is used to detect a motor and to generate a correction sense signal, which is immediately fed back to the speed control device to form a closed loop control, so that the rotation frequency of the motor may be automatically corrected and set.

Abstract: An actuator position control system for brush-type DC motors. The system includes a sensor, amplifier or differentiator, central control unit (microprocessor), and motor driver. The system utilizes the differential signal di/dt to indicate the falling edges of commutation spikes in the motor current profile. In a first embodiment, an inductor is selected as the signal sensor, because voltage drops across the inductor are directly proportional to di/dt. The voltage drop, L(di/dt), across the inductive sensor is input to the amplifier, amplified, and then sent to the microprocessor. In a second embodiment, a sensing resistor and a differentiator are substituted for the inductive sensor and amplifier, respectively. The microprocessor reads the output pulses from the amplifier or differentiator and compares the pulse count to an input command signal. The microprocessor then sends shaft position control information to the motor driver.

Abstract: A method for controlling a positioning device (34) of an internal combustion engine includes the step of providing an electric motor (30) for actuating a positioning device (34). A user employs an actuator (21) to command the throttle plate (34) to change to a commanded position. A motor effort sensor (38) then detects a control effort required by the motor (30) to change to the commanded position. A throttle control unit (28) determines whether the control effort exceeds a threshold for a predetermined time period. If the control effort exceeds the threshold for the predetermined time period, the throttle control unit (28) actuates the motor (30) to reduce the control effort.

Abstract: A motor drive circuit and method with frequency setting and correcting functions. The drive circuit includes a speed control device, which simultaneously receives a sense signal and a rotation frequency signal. A pulse width modulation signal capable of modulating a duty ratio may be generated by a pulse width modulation method. The pulse width modulation signal is then transferred to a drive timing controller that generates a timing control signal to control output timing of a power drive signal for the drive circuit. Meanwhile, a sensor is used to detect a motor and to generate a correction sense signal, which is immediately fed back to the speed control device to form a closed loop control, so that the rotation frequency of the motor may be automatically corrected and set.

Abstract: A control system for a linear actuator having an electric motor drawing a variable current level during operation. The control system includes a current level sensor for determining an operational current level of the linear actuator and a controller for generating a drive signal and a force request signal representative of a desired current level of the linear actuator. The drive signal remains constant during a predetermined time interval of the controller. The control system further includes a current limiting component for receiving the force request signal, the current level of the linear actuator and the drive signal. The current limiting component minimizes the current level of the electric motor in response to a comparison between the force request signal and the desired current level within a time interval substantially smaller than the predetermined time interval of the controller.

Abstract: Methods and systems for controlling a servo are provided. One method includes calculating at least a first switching time to change an amplitude of a command signal to a servo, providing a first amplitude to the servo for the first switching time, and switching the amplitude of the command signal to the servo from the first amplitude to a second amplitude at the first switching time. The second amplitude is the command signal amplitude.

Abstract: Apparatus and method for providing digital signal processing method for controlling the speed and phase of a motor involves inputting a reference signal having a frequency and relative phase indicative of a time based signal; modifying the reference signal to introduce a slew-rate limited portion of each cycle of the reference signal; inputting a feedback signal having a frequency and relative phase indicative of the operation of said motor; modifying the feedback signal to introduce a slew-rate limited portion of each cycle of the feedback signal; analyzing the modified reference signal and the modified feedback signal to determine the frequency of the modified reference signal and of the modified feedback signal and said relative phase between said modified reference signal and said modified feedback signal; and outputting control signals to the motor for adjusting said speed and phase of the motor based on the frequency determination and determination of the relative phase.

Abstract: Limits are imposed on a fundamental voltage command value calculated at a fundamental current control circuit that controls a fundamental component of a 3-phase AC motor current in a dq-axis coordinate system rotating in synchronization with the rotation of the 3-phase AC motor by using predetermined limit values and limits are imposed on a higher harmonic voltage command value calculated in an orthogonal coordinate system (a higher harmonic coordinate system) rotating at a frequency set to an integral multiple of the frequency of the fundamental component in the 3-phase AC motor current by using a predetermined limit values. The voltage command values resulting from the limit processing are added together and a voltage corresponding to the sum is applied to the AC motor for drive control.

Abstract: In a chopping energization control device, a pair of switching elements IGBT/U and IGBT/L are used to control an electric power supplied from a DC power source to a phase coil CL1 of a DC motor, particularly an SR motor, such that one of the switching elements is alternately turned on-and-off while the other is being turned on continually. To avoid uneven heat generations between the switching elements, an arrangement is provided wherein whenever a time elapses beyond a limit value of, for example, 10 milliseconds the conditions of the respective switching elements are swapped with each other. Such a swapping is established cyclically which causes equal heat generations in the switching elements.

Abstract: A vacuum cleaner operates via power supplied from either an on-board battery or an AC power outlet. When the vacuum cleaner is operating by using the battery a controller monitors the voltage level in the battery and automatically shuts down the vacuum cleaner when the battery voltage has decreased below a preset level. This prevents a full drainage of the battery and increases its longevity. The controller that monitors the battery voltage level can be used with batteries of different voltages. The controller automatically determines which type of battery is being used and shuts down power to the vacuum cleaner motor after the appropriate amount of battery drainage.

Abstract: A DC motor drive circuit includes a switching circuit that drives the coils of a small permanent magnetic DC motor. The drive circuit is preferably implemented in an integrated circuit device, such as a silicon CMOS device. Integrated into the same integrated circuit device is a magnetic sensor arranged to detect the position of the permanent magnet as it passes a defined point, or points, in its revolution, and control circuitry to derive the timing waveforms for driving the coils. The integrated power devices for driving the coils are also arranged to limit the rise and fall times of the applied voltages and currents so as to reduce or eliminate the generation of unwanted RFI. Additional circuitry is also integrated into the same integrated circuit device to derive the necessary power to operate the magnetic sensor, the control circuitry and the switching circuitry from the connections between the switching circuitry and the coils so as to remove the need for a separate power supply connection.

Abstract: When a playback signal of recorded data which is a DC free code has non-linearity, the playback signal is equalized by a waveform equalization unit, and sampled by an analog-to-digital converter. The sample data is binarized, and an offset amount is detected by utilizing the feature of the DC free code, and then the reference level of the analog-to-digital converter is controlled so that the output of a first integrator becomes 0. Thereafter, the output of a level shift circuit is input to a second integrator, and the level shift amount is controlled so that the output becomes 0. The converged value is retained. After this learning, by using the retained level shift amount, the reference level is controlled so that the output of the second integrator becomes 0, thereby performing speedy and accurate DC offset control.

Abstract: A control system for a linear actuator having an electric motor drawing a variable current level during operation. The control system includes a current level sensor for determining an operational current level of the linear actuator and a controller for generating a drive signal and a force request signal representative of a desired current level of the linear actuator. The drive signal remains constant during a predetermined time interval of the controller. The control system further includes a current limiting component for receiving the force request signal, the current level of the linear actuator and the drive signal. The current limiting component minimizes the current level of the electric motor in response to a comparison between the force request signal and the desired current level within a time interval substantially smaller than the predetermined time interval of the controller.