Abstract: A method and an apparatus for damping the vibrations of an alternating current motor is provided. The motor is supplied from an alternating current source with a supply voltage whose frequency is the basic frequency. Additionally the motor is fed with a second voltage having a frequency equal to the basic frequency multiplied by the quantity 2*m*q−1. In the equation, m is the number of the phases of the motor and q is the number of slots per phase.

Abstract: A rotor composite type three-phase stepping motor having a stator consisting of two stator elements each having 6 n pieces of stator magnetic pole with Ns pieces of pole tooth formed on the tip end of each stator magnetic pole piece, and a permanent magnet held by the two stator elements therebetween, a rotor of magnetic material arranged so as to face to a periphery of the stator through an air gap, Nr pieces of pole tooth being formed on a periphery of the rotor, and exciting windings wound around each stator magnetic pole piece of the stator elements consisting of two sets of three-phase windings each wound around 3n pieces of stator magnetic pole among the 6 n pieces of stator magnetic pole.

Abstract: A principal part of an attitude control system comprises: holding means 30 for holding wafers W so that the wafers W are rotatable in circumferential directions; rotation transmitting means 40 for contacting a peripheral portion of each of the wafers W to rotate the wafers W; a stepping motor 50 for rotating the wafers W; transmission switching means 60 for selectively transmitting a power from the stepping motor 50 to the rotation transmitting means 40; a photo sensor 70 for detecting a notch Wa formed in the peripheral portion of each of the wafers W; and a CPU 80 for controlling the operations of the stepping motor 50 and the transmission switching means 60 on the basis of a detection signal outputted from the photo sensor 70. Thus, the notch Wa of each of the rotating wafers W is detected, and the stepping motor 50 and the transmission switching means 60 are controlled on the basis of the detection signal, so that it is possible to carry out the positioning of the wafers W.

Abstract: According to a control device for a stepping motor of the present invention, in a first operation mode, a microstep driving section 16 is selected, and an output of this microstep driving section 16 is applied to a driving section 21 through a command selector 12, whereby a stepping motor 25 is microstep driven by this driving section 21. Furthermore, in a second operation mode, a forced driving section 15 is selected, and an output of this forced driving section 15 is applied to the driving section 21 through the command selector 12, whereby the stepping motor 25 is forced driven by this driving section 21, i.e., a high-speed rotation of a rotor 29 is started from any rotation angle with the microstep driving.

Abstract: A circuit on a curved surface is provided where the circuit includes at least one circuit element on the curved surface, at least one conductive path on, and integral with, the curved surface, where the conductive path is connected to the circuit element, and means for supplying power along the conductive path to the circuit element. The curved surface may be a helmet, in which case a plurality of pairs of light emitting elements may be provided thereon where the pairs emit light sequentially one pair at a time in order to maximize the brightness of the light emitted and maximize battery life. Also, means for receiving an infrared or ultrasonic signal may be provided such that the light emitting elements emit light in a certain manner as a result of the signal being received.

Abstract: A stepper motor controller and method for controlling the motion of a stepper motor by selectively energizing the motor's windings so that the current level in the windings match a desired current profile. The motor controller comprises a master logic device, preferably a microprocessor or microcontroller, which is programmed with logic for issuing control signals corresponding to the sequence with which the windings of the stepper motor are energized and the desired current profile. A portion of the control signals are received by a slaved logic device, which is programmed with logic for generating ramp command signals corresponding to the desired current profile. The slaved logic device produces a ramp command signal that is received by a digital potentiometer, which preferably includes an up/down counter. The output signal produced by the digital potentiometer corresponds to a current count value of the up/down counter, and it is controlled by the ramp command signals.

Abstract: A driving apparatus equipped with a step controlling circuit drives stepping motors in a micro stepping manner. An encoder which detects a mover position of the motor supplies a signal to the controlling circuit, thereby halting the micro-step-driving. This structure eliminates the influence by detent torque, and allows the apparatus to control a motor positioning in an accurate manner.

Abstract: A method and an apparatus for driving a stepping motor is provided. Digital desired current values are stored in the form of a sine table and are read from the sine table at a constant sampling frequency. The intervals between the read-out table values can be varied equally and unequally. The digital desired current values are converted into discrete analog signals. A sinusoidal signal is reconstructed from the analog signals. A motor current for exciting a phase of the stepping motor is derived from the sinusoidal signal.

Abstract: A control device for stepping motor including a driving pulse supplying unit for supplying a plurality of driving pulses to a driving coil for driving a rotor. A rotation detecting pulse supplying unit supplies rotation detection pulses for detecting whether the rotor rotated. A magnetic field pulse supplying unit supplies a plurality of magnetic field detection pulses for detecting the presence of magnetic field external to said stepping motor. A detection unit determines whether the driving rotor rotated and whether a magnetic field is present. An auxiliary pulse supplying unit supplies an auxiliary pulse when either rotor was not detected or when said an external magnetic field was detected. Before the driving pulse, is output, two said magnetic field detecting means magnetic field detecting pulses having different polarities are output.

Abstract: A circuit for use with a limited resolution device such as a stepper motor to convert a high-resolution signal such as from a computer into a high fidelity signal for driving the limited resolution device. The input to the limited resolution device being an average of the integrated difference between the high-resolution signal and a limited resolution signal consistent with the values used for driving the limited resolution device. This average being a high fidelity signal which is substantially the same as the high-resolution signal.

Abstract: The present invention provides a high precision three-dimensional alignment system using SPM techniques and method of using the same. The system comprises a fine distance control unit for the effective three-dimensional micromovement in the nanometer range of a planar object, and proximity detection unit to monitor the alignment process. In the preferred embodiment, the fine distance control unit comprises a set of at least three strategically positioned fine distance control elements which are capable of controlled expansion and contraction in the nanometer range. The most preferred embodiment of the fine distance control element comprises a piezoelectric tube, which crystal size may be varied by varying an applied voltage. This system may be applied to microlithography, in which case the planar object is a scribing tool having a planar base with multiple tips fabricated on one surface.

Abstract: An electric carrier with a motor controlled by correlative positions includes an operator possible to be a person, a sensor controlled by the operator and having a position reference member driven by and moving together with the operator and a sensing body producing signal at any movement of the position reference member, a spring connected to the position reference member and disfigured by the operator's driving so that the position reference member may return to its position and transmit force to an electric carrier to be mentioned below, a controller operating by signal coming from the sensing body, a motor driven by the controller and accordingly having functions of speed increasing and decreasing clockwise and counterclockwise rotation, and the electric carrier moved by the motor and with the operator synchronously.

Abstract: In an image forming apparatus which forms images by transferring to a transfer drum a toner image formed on the surface of the photosensitive member directly driven by a stepping motor, the relationship between the stepping angle ".theta." (.degree.) of the stepping motor and the rotational speed "N" (rpm) of the photosensitive drum is expressed by the equation .theta..ltoreq.(360.times.N)/(60.times.a.times.b). Where "a" is a natural number, optimally 10, which is less than the initial predetermined tolerance value when the harmonic content of rotational variation generated by the step period of the stepping motor is "1/a", and "b" is the target frequency (Hz) of 100.

Abstract: In an electronic apparatus such as a timing device capable of a quick-moving operation, a detecting coil wound coaxially with a driving coil for driving a rotor is arranged, a feedback-induced voltage appearing in the detecting coil is detected by a detector circuit, and a first peak appearing first subsequent to the supply of a drive pulse and having the same polarity as the drive pulse is picked up to detect the rotation of a rotor. Based on the detected timing of the first peak, a next drive pulse is supplied, and the drive pulse is thus fast supplied while the rotation of the rotor is checked. This arrangement allows a quick-moving operation free from faulty watch hand driving to run even faster.

Abstract: A three-phase stepping motor comprising: a rotation shaft rotatably supported by a pair of bearings provided in predetermined places of a housing so as to be in opposition to each other; a permanent-magnet rotor formed in a cylindrical shape so as to have south (S) and north (N) poles magnetized alternately in the direction of rotation on an outer circumferential portion of the rotor, or an induced magnetization rotor having S and N poles disposed alternately in the direction of rotation which are formed in a manner so that permanent magnets with the same polarity are fitted or formed so as to be identical in polarity at their surfaces in grooves formed parallelly to each other at a regular pitch in a surface of a magnetic body formed to be cylindrical in parallel to the rotation shaft and the cylindrical magnetic body is subjected to induced magnetization to form the S and N poles alternately in the surface of the cylindrical magnetic body; and a stator disposed so as to be in opposition to a surface of one

Abstract: A multi-phase PM-type stepping motor comprising: a rotor constituted by a cylindrical permanent magnet with N poles and S poles magnetized alternately on an outer circumferential surface of the rotor; stator cores having teeth arranged in opposition to the N poles or the S poles on the outer circumferential surface of the rotor through a predetermined air gap; and excitation coils wound in the stator cores and for magnetizing the stator cores to thereby rotate the rotor; wherein, when the number of the stator cores is represented by n (n is an odd number not smaller than 5), and the magnetization pitch angle of the permanent magnet is represented by P, the teeth of the stator cores are shifted from each other by an angle of 2P/n.

Abstract: In a preferred embodiment, a stepper motor control, including: a driver to drive the stepper rotor; a detector to detect a commanded step rate signal provided to the driver and to provide an output signal proportional thereto; a power control, responsive to the output signal, to provide driving power to the driver, and to increase voltage to the driver in proportion to an increase in magnitude of the output signal; and an over-current protection circuit that becomes active above a predetermined motor current level and above a predetermined commanded step rate. Voltage control can be effected either on the drive board or by controlling the power supply. An additional feature provides over-current protection for the stepper motor during a lock rotor (stall) condition. The stepper motor control produces very low levels of EMI/RFI as compared with PWM current control (chopper) drives.

Abstract: The voltage at a node between a pair of series-connected windings of a synchronous or stepping motor is monitored during operation so as to detect transition voltage regions, the durations of which are indicative of the torque load on the motor and which are used as the basis for controlling the driving current amplitude so as to achieve enhanced efficiency of energy utilization. An optimum value for the duration of the transition voltage region will usually be established as a target, and adjustments will be so made as to conform subsequently detected node voltage values to those of the target.

Abstract: The invention detects vibrations of a motor by a vibration detection means, compares the detected vibration detection value with a reference value using control means, and changes the voltage to be applied to each of coils of the respective excitation phases until the vibration detection value reaches the reference value, thereby controlling the excitation currents that flow through the coils of the respective excitation phases to reduce the vibrations of the motor.

Abstract: A low overhead controller for microstepping a stepper motor and a low overhead method for microstepping a stepper motor. The reduction in overhead in system processor is accomplished by the control circuit which dynamically interpolates motor positions between steps commanded from the processor. Also, the reduction in overhead is accomplished by a microstepping method used to effect microstepping resolution control by employing a stored look-up table which gives a resolution value at a given speed according to a predetermined function.

Abstract: A circuit for controlling the operation of switched reluctance machines (i.e., motor or generator) having a plurality of phase windings. The circuit slows down the initial "turn off" of the phase windings to eliminate an abrupt reduction in the current flowing therethrough. This reduces the impulse which excites mechanical oscillations in the motor/generator, reduces switching losses in the switching transistors, and reduces the number of harmonics.

Abstract: For driving a self-timing stepping motor which can be decelerated by an external load, a driving device presets a target step frequency and the motor is started with this target step frequency. The actual rotational speed of the stepping motor is determined and, as a function of this determined rotational speed, the target step frequency is changed when the rotational speed falls below a preset actual rotational speed of the stepping motor for a preset time interval.

Abstract: A system and method for controlling a stepper motor wherein the amount of memory space needed to store a phase table is minimized. The stepper motor controller comprises a memory sized to store data representing a plurality of states for current outputs to be supplied to a first winding of a stepper motor and from which are derived current outputs for the first winding and a second winding of the stepper motor. A finite state machine is coupled to the memory. The finite state machine comprises a first address register that stores an address for data in the memory for a present state of the first winding and a second register that stores an address for data in the memory for a present state of the second winding.

Abstract: Disclosed is a control apparatus for a position control motor, which allows the rotor of the motor to follow up to a command position without step out, can ensure highly reliable positioning, and is stable with respect to a variation in load. This position control apparatus comprises a position detecting section for detecting a rotor position of the position control motor, a control section for comparing an output signal of the position detecting section with a command position signal and outputting a signal corresponding to an electric current to flow in windings of the motor based on a deviation between the output signal and the command position signal, and a drive section for outputting an electric current to be supplied to the windings of the motor based on an output signal of the control section, and controls the position of the motor based on the command position signal.

Abstract: A method and system (10) for simultaneous operation of primary (14A-14D) and redundant (16A-16D) motor windings in a redundant stepper motor (12). The redundant motor system (10) has a control circuit (11) including a phase synchronizer (36) for establishing a relationship between predetermined primary and redundant motor windings (14A-14D and 16A-16D) such that the power consumption is increased and the motor torque is affected. In one embodiment of the present invention the predetermined motor windings (14A-14D and 16A-16D) are operated in phase thereby doubling the power consumption and increasing the torque. In another embodiment, the predetermined motor windings (14A-14D and 16A-16D) are operated in phase quadrature thereby doubling the power consumption and increasing the torque by less than 50%. In yet another embodiment, the predetermined motor windings (14A-14D and 16A-16D) are operated out of phase with each other thereby doubling power consumption and producing zero torque.

Abstract: A motor-speed control apparatus is provided for use on a scanner of the type having a movable scan head, such as a flatbed scanner, for the purpose of controlling the operation a stepper motor used to drive the CCD (charge coupled device) scan head of the scanner. In this motor-speed control apparatus, a Y data table is predetermined, which includes a number of Y data sets, each corresponding to one line in the lengthwise direction (i.e., the Y-axis direction) of the document being scanned. In operation of the scanner when the scan head is to be moved over the document, the manipulation on each pixel in the lengthwise direction is based on the predetermined values of the corresponding Y data set. This allows the scan head to move in a non-target area of the document (the area that is not to be scanned), and at a fixed speed when moving over the target area of the document (the area that is to be scanned).

Abstract: In an apparatus for driving a stepping motor in a micro step manner by a PWM control signal generated based on a sense voltage, including a sense resistor for generating the sense voltage, a driving current path including the sense resistor and the stepping motor is provided and is operated so that a driving current flows through the stepping motor, when the PWM control signal is activated. A regenerative current path including the sense resistor and is provided the stepping motor and is operated so that a regenerative current flows through the stepping motor, when the PWM control signal is not activated. A resistance of the regenerative current path is larger than a resistance of the driving current path.

Abstract: A driving apparatus using a motor has a stepping motor, a moving mechanism, and a driving circuit. The moving mechanism moves an object to be driven on the basis of a driving force of the stepping motor. The moving mechanism moves the object among a plurality of moving points set on the basis of even-number steps of the stepping motor. The driving circuit supplies a plurality of drive signals equal to a plurality of even-number steps to the stepping motor.

Abstract: A method and circuit for controlling a motor and reducing and/or eliminating mid-velocity instability in the motor are provided. The method includes the step of receiving a decay time indicative signal that is indicative of the current decay time in a phase coil of the motor after current commutation. The decay time indicative signal assumes a first polarity proportional to the current decay time in the phase coil. The method further includes the step of calculating a delay time corresponding to the amount of time the decay time indicative signal has the first polarity. Finally, the method includes the step of controlling the direction of current in the phase coil or another phase coil of the motor responsive to the delay time and a current direction signal generated by a translator. The inventive method and circuit enable reduction and/or elimination of mid-velocity instability even when the motor is operated in a microstepping mode.

Abstract: A motor driving apparatus including a stepping motor constituted by a stator having at least two poles. The driving apparatus includes a circuit for biasing one terminal of a driving coil of a motor to an intermediate potential of a power supply voltage. A counterelectromotive voltage detection circuit for detecting a counterelectromotive voltage generated upon rotation of a rotor is arranged at the other terminal. A pulse signal to rotate the rotor is output on the basis of a detection signal output from the counterelectromotive voltage detection circuit.

Abstract: A motor controller includes an input terminal (22), a frequency selective network, a first controller, and a second controller. The input terminal is adapted to be coupled to a drive phase of a motor (16) for receiving a signal (24). The frequency selective network (18) has an input coupled to the input terminal (22) and an output for providing a first signal representative of the back EMF signal within a frequency range corresponding to a predetermined harmonic frequency above a primary frequency thereof. The first controller (20) has an input coupled to the output of the frequency selective network (18) and an output for providing a second signal representative of a position or a velocity of a rotor of the motor (16). The second controller (10) has an input coupled to the output of the first controller (20) and an output for providing a third signal. The third signal indicates how the motor (16) is to be driven.

Abstract: When implementing an origin reset, operating conditions for the origin reset are corrected in correspondence to changes in operating conditions such as the source voltage to implement an accurate origin reset.

Abstract: A printer includes a drive pulse controller which continues to output drive pulses for driving a stepping motor (M) in a forward direction after a movable member (20) has come up against a stopper (34), and thereafter stops output of the drive pulses after step out of the motor (M). The printer also includes a setting device for setting a stop phase which the stepping motor (M) takes when it starts moving in a reverse direction.

Abstract: In an opening/closing member driving method in which the rotation of a motor rotatable in two directions is transmitted through a transmission member to an opening/closing member to thereby drive a baffle 4 in an opening direction A and in a closing direction B, when driving the transmission member from an intermediate position to an original position which is set at a position where the transmission member is moved to the full in one direction or in the other direction, the transmission member is once driven in the opposite direction to the original position and is stopped at such opposite position or in the neighborhood of the opposite position and, after then, the transmission member is driven in the original position direction by an amount equivalent to the normal movement thereof and is thereby returned to the original position.

Abstract: An image processing apparatus (10), typically for sheet thermal print media. The image processing apparatus (10) typically comprises a vacuum imaging drum (300) for holding thermal print media (32) and dye donor sheet material (36) in registration on the vacuum imaging drum (300). A printhead (500), driven by a lead screw (250), moves along a line parallel to a longitudinal axis (301) of the vacuum imaging drum (300) as the vacuum imaging drum (300) rotates. The printhead (500) receives information signals and produces radiation which is directed to the dye donor material (36) which causes color to transfer from the dye donor material (36) to the thermal print media (32). A stepper motor (162) that turns the lead screw (250) can run in a microstepping mode.

Abstract: A method and apparatus for operating stepping motors in a printer or copier senses temporarily changes in the moment of resistance caused by the introduction of the leading edge of the paper and overcomes this change in moment by changing the current amplitude to the motor windings. The currents are modified at a starting time, as determined by sensors.

Abstract: A drive circuit with signal detection capability for a DC brushless fan motor is disclosed. The drive circuit comprises a Hall effect sensor for detecting the magnetic polarity of the rotor in the fan motor, first and second transistors connected to first and second magnetic coils respectively for alternately generating magnetic fields to continuously rotate the rotor of the fan motor and further comprises a series RC circuit and a field effect transistor for detecting the operation of the fan motor. A signal detection line connected to the source of the field effect transistor is provided for detecting the operation of the fan motor. When the fan motor is running normally, the signal detection line presents a square wave signal with frequency proportional to the rotating speed of the fan motor. When the motor stops running, the signal detection line always presents a high level signal.

Abstract: A control system of a step motor and a method thereof are capable of evenly maintaining a traveling distance and a torque in a moving section, especially in an accelerating section, by limiting a start excitation phase or a final stop phase to a specific phase, even though an excitation and the torque are unevenly generated due to an imbalance in a step angle generated during the manufacturing and/or assembly of the step motor.

Abstract: A stepping motor driving apparatus for a camera includes 1-2 phase excitation type stepping motors and a drive controller for driving and stopping the stepping motors so that the driven stepping motors are stopped always at a detent position.

Abstract: A positional determination device which is drived according to the pulse signals output to a stepping motor 1 and displaces a nut 2 to a position corresponding to the degree of rotation. In order to adjust the initializing position of a feed mechanism, the stepping motor 1 is rotated and the nut 2 displaces until it reaches the limiting position (LimA) defined by the stopper 3a. When initializing, the pattern of temporarily stopping the stepping motor 1 for a period corresponding to a pulse number (N2) at each pulse number (N1) and rotating is repeated. As a result the rotations of the stepping motor 1 become gentle and even if the nut 2 were to collide with the stopper 3a at the limiting position, the reverse rotation of the stepping motor 1 can be prevented and accurate adjustment of the initializing device can be performed.

Abstract: To control the current through a winding interconnected in an H-bridge to control e.g. a stepping motor, at the beginning of each chopper period, the H-bridge is kept in its slow demagnetization state during predetermined interval (t1-t2). Then, just before, at or just after the end of that interval, the actual current value (IA) is compared with a desired value (ID). If the actual value (IA) is smaller, the H-bridge is kept in its magnetization state, at the most until the end of the chopper period. If the actual value is larger, the H-bridge is kept in its fast demagnetization state, at the most until the end of the chopper period. Hereby, the current is regulated to the desired value with a minimum of current ripple. This reduces the electromagnetic radiation. Also, the impact of current spikes, appearing when the H-bridge is switched, is brought to a minimum.

Abstract: A stepping motor driving apparatus for a camera having a 1-2 phase excitation type stepping motor which is driven by a 1-2 phase excitation in response to a drive signal includes a drive control device for stopping the stepping motor at a 1-phase excitation position by de-energizing the stepping motor at the 1-phase excitation position and for stopping the stepping motor at a 2-phase excitation position while maintaining the excitation in a high precision drive control in which the stepping motor is driven at high precision. The drive control device stops the stepping motor by de-energizing the stepping motor always at the 1-phase excitation position in a normal drive control in which no precise drive control of the stepping motor is needed.

Abstract: A measure obtained by a counting circuit (2) is converted by a processing circuit (3) to an indication angle signal at a predetermined conversion cycle. A smoothing circuit (4) comprises a division circuit (11) for calculating the difference between the previous indication angle data .theta..sub.0 and the present indication angle data .theta..sub.1 which is outputted after the conversion cycle T and has changed, and sequentially accumulating the angle data corresponding to T/n (where n is an integer of 2 or more) shorter than the conversion cycle T at a division cycle T/n and a voltage memory (12) for converting and outputting a two-phase driving signal for driving a stepper motor type measuring instrument (6) on the basis of the indication angle data .theta..sub.i outputted from the division circuit (11) every division cycle T/n. A voltage signal is generated through an output circuit (5) for converting the signal to a voltage signal to be applied to a two-phase excitation coil of a stepper motor.

Abstract: A stepping motor control apparatus for controlling a stepping motor to drive a fluid flow control valve in an engine includes an operation state monitoring unit for monitoring the operation state of the engine; a step position monitoring unit for monitoring a step position of the stepping motor; a first motor drive direction-determining unit for determining the motor drive direction during normal operations of the stepping motor as determined by a target step position and the present step position of the stepping motor; a second motor drive direction-determining unit for determining the motor drive direction during anomalous operations of the stepping motor; a drive pulse-rate determining unit for determining the pulse generation rate to drive the stepping motor; and a drive unit for driving the stepping motor at the pulse generation rate determined by the drive pulse-rate determining unit.

Abstract: A camera, an optical apparatus or an optical unit controller having a device for driving an optical unit, a device for determining a state of movement of the optical unit, and a control unit for changing the direction of movement of the optical unit according to whether the amount of driving necessary for the driving device to move the optical unit to a position at which the determination device determines the state of movement of the optical unit is equal to or smaller than a predetermined amount.

Abstract: The method includes applying to the coil (3) of the motor (2) driving pulses having alternately a first and a second polarity, supplying the coil (3) with a determined quantity of electric energy during each driving pulse, detecting, after each driving pulse, the rotation or non rotation of the rotor of the motor (2) in response to said driving pulse, and adjusting said determined quantity of electric energy as a function of said detection.In order to further reduce the quantity of electric energy consumed by the motor, the method is characterised in that the adjustment of the quantity of electric energy supplied to the coil (3) is effected separately for the driving pulses having the first polarity and for the driving pulses having the second polarity.

Abstract: A playback, recording and/or extracting machine for disks designed as information carriers has opposite disk magazines that receive disk-holders or at least one disk in horizontally superimposed disk-receiving compartments and a computer-controlled transport device arranged between the disk magazines and provided with two horizontally movable drawing-out mean for the disk-holders. In order to monitor the driving motor of the transport device and drawing-out means, the driving motor is connected to an incremental signal generator that incrementally detects the position of the driving motor and thus allows the transport device and drawing-out means to be automatically and precisely positioned.

Abstract: A system and method are provided for controlling a stepper motor having a rotor and a multi-phase stator. Sinusoidal command signals define a commanded position of the motor's rotor. An actual position of the rotor is sensed as a function of an electrical angle between the actual position and the commanded position. The actual position is defined by sinusoidal position signals. An adjustment signal is generated using the sinusoidal command signals and sinusoidal position signals. The adjustment signal is defined as a function of the cosine of the electrical angle. The adjustment signal is multiplied by each sinusoidal command signal to generate a corresponding set of excitation signals, each of which is applied to a corresponding phase of the multi-phase stator.

Abstract: A stepper motor that turns a lead screw runs in microstepping mode. To compensate for positional error in microstepping, the method utilizes the characteristic sinusoidal positional error behavior that is measured at four times the frequency of the composite microstepping current waveform, using a correction factor that is in phase with this positional error.

Abstract: The invention concerns both a method for controlling a traversing device driven by a stepping motor and a traversing device, in which the position of a traversing thread guide which is moved to and fro within a traversing stroke is determined by the position of a rotor of the stepping motor, the rotor moving within a stator of the stepping motor with several windings. The movement of the rotor is controlled, according to the invention, by a stator flux which is determined by a stator voltage generated by means of a flux control device.