Abstract: A motor control apparatus and a motor control method determine whether the motor is in a back-pressure area so as to provide different rotation-speed control signals. When the fan is in the low duty cycle, a first circuit loop is switched on, so that the fan has more accurate rotation speed. When the fan is in the high duty cycle, a second circuit loop is switched on, so that the rotation speed of fan does not be limited to a constant rotation-speed as the fan enters the back-pressure area. Thus, the fan has larger airflow quantity and higher airflow pressure.

Abstract: A controller 40 performs a control operation in a cycle based on a carrier frequency fc of a carrier, specifically, at timings corresponding to the peaks and troughs of the carrier signal. Moreover, in the case where the carrier frequency fc is switched, a disturbance estimation part forming the controller 40 updates control constants that are used for disturbance estimation and are dependent on the control operation cycle, in a control operation performed one cycle after a control operation immediately after the switching of the carrier frequency fc.

Abstract: A control system for an electric machine, the control system including a current controller and a drive controller. The current controller includes an input, an output, a comparator and a latch. The comparator sets the latch when a voltage at the input exceeds a threshold, and the latch outputs an overcurrent signal when set. The drive controller then resets the latch after a predetermined period of time.

Abstract: A motor driving circuit has a motor operated with a forward operation, a reverse operation, an inactivating operation, and/or a brake operation under a constant current mode, a constant voltage mode, and/or a full swing mode. The motor driving circuit also prevents usage of multiple operational amplifiers and errors brought by the usage of the multiple operational amplifiers with simple circuit designs.

Abstract: A motor control device has a motor driving circuit for driving a motor, a current detection circuit for detecting a motor current flowing through the motor driving circuit, and a controller for calculating a detected value of the motor current based on an output of the current detection circuit, comparing the detected value with a target value of the motor current, and generating a command value for allowing a motor current of the target value to flow through the motor based on a deviation therebetween, to output the command value to a motor driving circuit. The current detection circuit is configured of a first current detection circuit having a positive first gain and a second current detection circuit having a negative second gain obtained by inverting the first gain.

Abstract: An electrically commuted reversible synchronous motor is activated in a calibration journey using an externally forced rotating field, during which an electrical angle of a rotating field and a mechanical angle of the rotor are measured simultaneously at a reference position by an external sensor. These items are stored associated with one another as a measurement series of value pairs. The electrical angle of the rotating field and the mechanical angle of the rotor are also detected simultaneously after direction reversal of the rotating field. These are stored as a second measurement series of value pairs. The angle difference between the electrical angle and the mechanical angle are calculated from value pairs of both measurement series. The correction value for taking the actual incorrect angle into consideration is calculated from the two angle differences by averaging.

Abstract: This inverter device includes a power portion performing PWM control on a voltage command to a motor for each set time period, converting direct-current power into alternating-current power, and outputting the same, a voltage command generation portion generating a voltage command in synchronization with a period N-times (N?1) longer than the time period, an interval determination portion generating an interval determination signal which is ON during a half period of the time period and OFF during the next half period, a current detection portion detecting the current of the motor at timing of change in the interval determination signal, and a voltage correction portion generating a voltage correction value such that the amount of change in the detected current when the interval determination signal is ON becomes equal to the amount of change in the detected current when it is OFF and correcting the voltage command.

Abstract: A fan control system for controlling a fan to dissipate heat from an electronic device includes a current detection circuit having a shunt resistor to receive current, a signal amplification circuit having an operational amplifier, and a switch circuit having an npn transistor and a pnp transistor. A first terminal of the shunt resistor is connected to the electronic device, a second terminal of the shunt resistor is connected to the electronic device via a power source and is grounded. A non-inverting terminal of the operational amplifier is connected to the first terminal of the shunt resistor, an inverting terminal of the operation amplifier is connected to the second terminal of the shunt resistor via a first resistor and connected to an output terminal of the operational amplifier via a second resistor. The output terminal of the operation amplifier is grounded via a third resistor and a sixth resistor.

Abstract: An image forming apparatus includes a longitudinally conveying motor, a main-body-side control board, and a sensor. In the longitudinally conveying motor, an encoder generates an encoder signal having a frequency corresponding to the number of rotations of the longitudinally conveying motor, and a sensor signal superimposing unit receives an input of a logical state of the sensor. The sensor signal superimposing unit superimposes the logical state of the sensor on the encoder signal by modulating a duty ratio of the encoder signal based on the logical state of the sensor, and outputs a post-superimposition encoder signal. In the main-body-side control board, a sensor signal separating unit obtains the logical state of the sensor by demodulating the input encoder signal.

Abstract: An H-bridge circuit is connected to a coil of the vibration motor that is to be driven. A comparator receives Hall signals indicating position information of a rotor of the vibration motor, and converts to an FG signal. A pulse width modulator generates a pulse-modulated pulse signal specifying energization time of the coil of the vibration motor. The pulse width modulator, in a first mode, after commencing start-up of the vibration motor, sets a duty ratio of the pulse signal to 100%, and after that, switches the duty ratio to a predetermined value in accordance with rotational frequency of the motor. In a second mode, the duty ratio of the pulse signal continues to be set to 100%. In a third mode, frequency and the duty ratio of the pulse signal are set based on a control signal of a pulse form inputted from outside. The control signal is used also in switching mode.

Abstract: A driving device capable of driving a motor more efficiently is provided. A zero-crossing detection comparator 10 compares a pair of Hall signals H+ and H? having reverse phases and representing a rotor position of a fan motor 6, and generates a level-shifted zero-crossing detection signal S1 at each zero-crossing timing when the Hall signals cross each other. A control circuit 20 receives the zero-crossing detection signal S1, switches a driving phase at each zero-crossing timing to rotationally drive the motor, and regeneratively controls the motor during a duration from a first time point ahead of each zero-crossing timing by a first time width ?1 to a second time point behind each zero-crossing timing by a second time width ?2 shorter than the first time width ?1.

Abstract: An apparatus and method for driving a motor of an air conditioner are disclosed. A method for driving a motor of an air conditioner includes driving the motor in response to a predetermined speed command, sequentially detecting first and second mechanical angles in response to the speed command or a reference speed being spaced apart from the speed command by a predetermined range, calculating a maximum speed mechanical angle corresponding to a maximum speed ripple of the motor on the basis of the detected first and second mechanical angles, and compensating for load torque of the motor on the basis of the calculated the maximum speed mechanical angle. As a result, the speed ripple is decreased during the constant speed operation.

Abstract: A motor driving circuit capable of outputting a dual FG signal includes a control unit, a first Hall unit, a second Hall unit and a logic unit. The control unit is electrically connected to the first Hall unit and configured to generate a first FG signal based on a Hall signal sent by the first Hall unit. The second Hall unit is configured to detect the change in magnetic fields to generate a second FG signal to the logic unit. The logic unit is electrically connected to the control unit and the second Hall unit. The logic unit is configured to perform a logic operation based on the received first and second FG signals to convert them into a dual FG signal for an external system. With the control unit, the first Hall unit, the second Hall unit and the logic unit being integrated in the motor driving circuit, the convenience in use can be improved greatly. Furthermore, the working hours and the production cost can be reduced.

Abstract: A DC brushless motor includes a rotary actuation shaft having multiple poles. Each of the poles has multiple commutation steps. The DC brushless motor also includes a motor controller capable of controlling rotation of the rotary actuation shaft. The motor controller stores a commutation step map.

Abstract: A system includes a power control module, a period determination module, and a control module. The power control module controls current through stator coils of a motor to rotate a rotor. The period determination module determines a first length of time between a first set of induced stator coil voltages and determines a second length of time between a second set of induced stator coil voltages. The control module determines whether an external disturbance disturbs rotation of the rotor based on a difference between the first and second lengths of time.

Abstract: A system for determining a commutation state for a brushless DC motor includes a controller configured to control current that is applied to drive each of a plurality of phases of the motor. A time delay system is configured to measure, for a given commutation state, a time delay from when a voltage associated with a driven phase of the plurality of phases crosses a predetermined threshold and a voltage associated with a floating phase of the plurality of motor phases crosses the predetermined threshold. Logic is configured to determine the commutation state for the motor based on the measured time delay.

Abstract: An electric motor control apparatus that can quickly and accurately locate a short-circuit fault point. The electric motor control apparatus includes: a current controller determining respective phase voltage commands according to currents flowing in respective phases of an electric motor and a torque current command; a switching element drive circuit instructing, based on the respective phase voltage commands, an inverter to perform a switching operation; the inverter receiving a switching operation signal to drive the electric motor; current detectors disposed in series with the switching elements in the respective phases of the inverter; and a short-circuit point locating mechanism storing a test pattern indicative of a predetermined combination for turning on the switching elements of the inverter, and locating a short-circuit fault point based on the test pattern and current detection values in the respective phases detected by the current detectors in response to the test pattern.

Abstract: A motor driving apparatus has a loss-of-synchronism monitoring circuit that monitors the rotation of a rotary machine such as a brushless DC motor to detect a sign of transition to a state of loss of synchronism. When the sign is detected, an energization control circuit temporarily stops driving of the rotary machine to bring it into a free running state, and thereafter carries out control so as to resume driving of the rotary machine. Further, the motor driving apparatus has an inverter and a drive control circuit that controls switching operation of the inverter based on rotation of the rotary machine.

Abstract: A method and system for a commutation control circuit are provided. The system includes an integrating voltage counter electrically coupled to an electrical power bus, wherein the integrating voltage counter is configured to integrate over time a voltage signal received from the power bus and to generate a trigger signal when the integrated voltage signal equals a predetermined count. The system also includes a plurality of transistor pairs configured to receive a trigger signal generated by the integrating voltage counter and electrically coupled to respective windings of a motor.

Abstract: The invention relates to a method for operating an actuating drive having an electrically commutated motor 1 for adjusting an actuating member, having a position sensor 6 for detecting the rotary angle position of the rotor of the motor or of an element which can be driven in a rotatable manner by said motor. A motor control unit 9 serves to commutate the motor 1 and to regulate the position of the actuating member, it being possible to supply position signals, which correspond to the position values detected by the position sensor 6, to the motor control unit 9. After the actuating drive is started, uncompensated measured values are detected by the position sensor 6 over at least one full revolution of the rotor or of the element which can be driven in a rotatable manner; corresponding correction values for compensating angle errors are formed in a compensation unit 11.

Abstract: A first duty ratio of a drive command signal is computed by comparing a level of the drive command signal with a first threshold value at a motor controller of a blower motor apparatus. A second duty ratio of the drive command signal is computed by comparing the level of the drive command signal with a second threshold value at the motor controller. A control signal is generated based on the first duty ratio and the second duty ratio in the motor controller and is used to drive a blower motor of the blower motor apparatus.

Abstract: An electronically commutated motor (ECM) often employs a Hall sensor for reliable operation. Even when a Hall sensor is omitted from a motor having a plurality of stator winding phases (24, 26) and a permanent-magnet rotor (22), one can reliably detect direction of rotation of the rotor by the steps of: (a) differentiating a voltage profile obtained by sampling either (1) induced voltage in a presently currentless phase winding or (2) voltage drop at a transistor, through which current is flowing to a presently energized phase winding, and (b) using such a differentiated signal (du—24?/dt, du—26?/dt) to control current flow in an associated phase winding. In this manner, one obtains reliable commutation, even if the motor is spatially separated from its commutation electronics.

Abstract: An electronically commutated motor (ECM) often employs a Hall sensor for reliable operation. Even when a Hall sensor is omitted from a motor having a plurality of stator winding phases (24, 26) and a permanent-magnet rotor (22), one can reliably detect direction of rotation of the rotor by the steps of: (a) differentiating a voltage profile obtained by sampling either (1) induced voltage in a presently currentless phase winding or (2) voltage drop at a transistor, through which current is flowing to a presently energized phase winding, and (b) using such a differentiated signal (du—24?/dt, du—26?/dt) to control current flow in an associated phase winding. In this manner, one obtains reliable commutation, even if the motor is spatially separated from its commutation electronics.

Abstract: The brushless motor driver includes a sample and hold circuit which samples and holds a first value of the first comparison signal in a first case in which a current is forced to flow from a first phase coil of the three-phase brushless motor to a second phase coil and no current is forced to flow to a third phase coil in a first period having a preset setting time and a second value of the first comparison signal in a second case in which a current is forced to flow from the second phase coil to the first phase coil and no current is forced to flow to the third phase coil in a second period having the preset setting time subsequent to the first period. The brushless motor driver includes an addition circuit which adds up the first value and the second value sampled and held by the sample and hold circuit and outputs an addition signal depending upon a result of the addition.

Abstract: Systems and methods of controlling a permanent magnet motor without a mechanical position sensor are provided. In accordance with one embodiment, a motor control system includes an inverter configured to receive direct current (DC) power and output a power waveform to a permanent magnet motor, driver circuitry configured to receive control signals and drive the inverter based upon the control signals, a current sensor configured to determine a sampled current value associated with the power waveform, and control circuitry configured to generate the control signals based at least in part upon a comparison of a flux-producing component of the sampled current value and a flux-producing component of a command reference current value.

Abstract: A motor controller is disclosed. The motor controller includes a current detector that is provided in a direct current side of a power converter and that detects direct current information. A determiner determines a size of an offset voltage contained in the detected current information. The determiner calculates the offset voltage by canceling a positive current component by a negative current component both pertaining to the same one phase and contained in the detected direct current information. A modifier modifies the detected direct current information based on the calculated offset voltage.

Abstract: A system includes a power control module, a period determination module, and a control module. The power control module controls current through stator coils of a motor to rotate a rotor. The period determination module determines a first length of time between a first set of induced stator coil voltages and determines a second length of time between a second set of induced stator coil voltages. The control module determines whether an external disturbance disturbs rotation of the rotor based on a difference between the first and second lengths of time.

Abstract: In a vehicular rotary electric machine, a switching section includes a bridge circuit having plurality of upper arms and plurality of lower arms. The arms include switching elements. A diode is connected in parallel to each switching element. One end of the switching element of each of the upper arms is connected to a positive terminal of a battery and one end of the switching element of each of the lower arms is connected to a negative terminal of the battery via a vehicle body. The switching section rectifies induced phase voltage of an armature winding. A section sets ON-timing of the switching elements. A section sets OFF-timing of the switching elements. When the switching element of each lower arm is OFF, a detector detects an energization period in which current flows to the diode. A calculator calculates a rotation frequency based on the detected energization period.

Abstract: A low speed region position estimating portion is designed to be suitable for when the motor is operating in a low speed region, and estimates a low speed estimated rotational position ?^L. A high speed region position estimating portion is designed to be suitable for when the motor is operating in a high speed region, and estimates a high speed estimated rotational position ?^H. A dividing portion obtains a divided estimated rotational position ?^M by internally dividing the low speed estimated rotational position ?^L and the high speed estimated rotational position ?^H. A rotation speed calculating portion obtains a rotation speed ? of a rotor based on an output signal from a steering sensor. The rotational position of the rotor is then obtained by selecting one of i) the low speed estimated rotational position ?^L, the high speed estimated rotational position ?^H, or the divided estimated rotational position ?^M, based on that rotation speed ?.

Abstract: A drive control signal is effectively obtained. An offset is added to a rotational state signal. A drive control signal having a period which is reduced by a predetermined period compared to the sine wave form signal is generated between a crossing of a reference value for a second time and a crossing of the reference value for a next time by an added signal obtained by sequentially offsetting the rotational state signal in a direction reaching the reference value. A pulse indicating that the polarity has been reversed when the offset is added is added to the crossing of the reference value for the first time, to reliably detect crossing of the reference value for the second time.

Abstract: A drive device having an electric motor with a device for field oriented control of the electric motor and a method for operation thereof is disclosed. An error monitoring of a transducer on the electric motor is achieved by a comparator device for comparing a transducer signal of the transducer on the electric motor with a calculated parameter of the field oriented control, the comparator device recognizing a transducer error and/or a coupling error. The coupling error relates to a coupling for mounting the transducer on the electric motor.

Abstract: A motor rotation irregularity detection circuit includes a first integrator for integrating a rotation detection signal that is output from a driver of a sensor-less motor; a differentiator for outputting a difference between a binary signal based on the integral in the first integrator and the rotation detection signal; a second integrator for integrating an output signal of the differentiator; a comparator for making a comparison between the integral in the second integrator and a reference voltage to output an irregularity detection signal; and an output terminal for outputting a signal coming from the comparator.

Abstract: A switching regulation circuit for a dual-winding motor apparatus is provided. The switching regulation circuit comprises a gate-controlled device and a driving circuit. When one of the two windings generates an induced voltage signal greater than a threshold value, the driving circuit generates an output signal for turning on the gate-controlled transistor. Thereby, a parasitic diode of the gate-controlled device will not be turned on and damage the entire circuit.

Abstract: A current measuring circuit for an electric motor provides an output indicative of the change in the current di/dt flowing in a phase of the electric motor over a measurement period of time. The circuit includes a current measurement element having a resistance; a switch which in use selectively permits transmission of a voltage dependent upon the instantaneous value of the voltage dropped across the current measurement element to a part of the circuit; and a switch controller which is adapted to operate the switch in response to timing signals supplied by the switch controller so as to define the measurement period of time.

Abstract: The present invention relates to an AC motor control device and, particularly, to provide an AC control device capable of simply setting a state quantity of an AC motor non-linearly variable, in accordance with the motor driving state and using the setting in motor control, the present invention can be achieved by including a state quantity calculating unit (13, 13a, 13b, 13c) for calculating a state quantity corresponding to a coil interlinkage flux which is an internal quantity of the motor, calculating a setting value of the coil interlinkage flux defined on one axis out of two axes, that is, d and q axes, with a function formula using a current defined on the same one of the axes and a function formula using a state variable defined on the other one of the axes.

Abstract: There are provided a laundry treatment machine and a method of controlling the same. A temperature around a motor is sensed and the range of current input to the motor in accordance with the sensed temperature is limited in stages. Therefore, the surrounding of the motor can be prevented from being overheated. In addition, since the range of the current input to the motor is limited in stages, when the current applied to the motor is limited, abnormal noise is not generated and the torque of the motor can be maximized.

Abstract: A fan controlling circuit for detecting rotational speed of a fan, includes a comparison circuit and a controlling chipset. The comparison circuit receives a rotational speed signal from the fan at one input terminal, a reference voltage at another input terminal, and outputs a filtered rotational speed signal at an output terminal. The controlling chipset receives the filtered rotational speed signal, and outputs control signals to control the rotational speed of the fan.

Abstract: A first calculation unit subtracts third digital data which indicates the minimum value of the duty ratio from first digital data which indicates the duty ratio of the PWM driving operation. A slope calculation unit generates slope data which is dependent on the temperature based upon second digital data which indicates the temperature. A second calculation unit multiplies the slope data by the output data of the first calculation unit. A third calculation unit sums the output data of the second calculation unit and the third digital data. A selector receives the output data of the third calculation unit and the third digital data, selects one data that corresponds to the sign of the output data of the first calculation unit, and outputs the data thus selected as a duty ratio control signal.

Abstract: A method of constant airflow control for a ventilation system is disclosed. The method includes various controls to accomplish a substantially constant airflow rate over a significant change of the static pressure in a ventilation duct. One control is a constant I·RPM control, which is primarily used in a low static pressure range. Another control is a constant RPM control, which is primarily used in a high static pressure range. These controls requires neither a static pressure sensor nor an airflow rate sensor to accomplish substantially constant airflow rate while static pressure changes. This is because these controls use only intrinsic control variables which are electric current and rotational speed of the motor. Also, the method improves the accuracy of the control by correcting certain deviations that are caused by the motor's current-RPM characteristics. To compensate the deviation, the method adopts a test operation in a minimum static pressure condition.

Abstract: A motor driving circuit capable of outputting a dual FG signal includes a control unit, a first Hall unit, a second Hall unit and a logic unit. The control unit is electrically connected to the first Hall unit and configured to generate a first FG signal based on a Hall signal sent by the first Hall unit. The second Hall unit is configured to detect the change in magnetic fields to generate a second FG signal to the logic unit. The logic unit is electrically connected to the control unit and the second Hall unit. The logic unit is configured to perform a logic operation based on the received first and second FG signals to convert them into a dual FG signal for an external system. With the control unit, the first Hall unit, the second Hall unit and the logic unit being integrated in the motor driving circuit, the convenience in use can be improved greatly. Furthermore, the working hours and the production cost can be reduced.

Abstract: A motor control device includes a dq-axis current control unit for generating a dq-axis voltage reference based on a dq-axis current reference and a dq-axis current signal, an initial magnetic pole position estimation unit for estimating a magnetic pole position of the motor upon power-on to generate a magnetic pole position signal, and a magnetic pole position estimation precision confirming unit for supplying a current in a d-axis direction after generation of the magnetic pole position signal with the initial magnetic pole position estimation unit, and checking an error of the magnetic pole position signal based on an angle of movement of the motor.

Abstract: A fan motor speed control circuit includes: a driving circuit configured to drive a fan motor so as to run at a rotation speed corresponding to a drive signal; a comparison circuit configured to output a comparison signal for matching a rotation speed of the fan motor with a target rotation speed, based on a reference signal corresponding to the target rotation speed of the fan motor and a speed signal corresponding to the rotation speed of the fan motor; and a selection circuit configured to output to the driving circuit the drive signal corresponding to one signal out of the reference signal and the comparison signal, the one signal being a signal by which the fan motor is driven at a higher rotation speed.

Abstract: A motor drive circuit includes a first amplifier circuit to amplify a difference between first and second position detection signals with a gain becoming smaller according to drop in power supply voltage, to output a first amplification signal, the first and second position detection signals being signals indicating a rotational position of a rotor in a motor, having a frequency corresponding to a rotation speed of the motor, and being opposite in phase to each other; a second amplifier circuit to amplify the difference between the first and second position detection signals with the gain, to output a second amplification signal opposite in phase to the first amplification signal; and a drive circuit to amplify the difference between the first amplification signal and the second amplification signal with a predetermined gain to be saturated at the power supply voltage, to output a driving voltage for driving the motor.

Abstract: A motor drive circuit comprising: first and second transistors connected in series, a voltage of a connection-point therebetween being a drive-voltage applied to one end of a motor coil; an operational amplifier for controlling the transistors such that the drive-voltage is a voltage according to a difference between first and second control voltages; a switch circuit for driving the transistors such that the motor coil is in an undriven state regardless of control by the operational amplifier when a pulse-signal is at one logic level, and driving the transistors based on the control when the pulse-signal is at the other logic level; and an auxiliary drive circuit for driving the transistors to increase the drive-voltage for a predetermined time period shorter than a time period of the pulse signal being at the other level regardless of the control, when the pulse-signal changes from the one level to the other.

Abstract: A control circuit (120, 140) for a brushless direct current (DC) motor (160) includes a current drive circuit (140), a current loop regulator (122), and a commutation loop regulator (124, 126). The current drive circuit (140) is adapted to drive the brushless DC motor (160) in a first polarity or a second polarity selectively in response to a control signal, and senses a current through the brushless DC motor (160) to provide a current sense signal. The current loop regulator (122) varies a duty cycle of the control signal to regulate the current in response to the current sense signal, and regulates the polarity of the current based on a state of a polarity signal. The commutation loop regulator (124, 126) regulates a transition of said polarity signal in response to a comparison of a pre-commutation duty cycle value and a post-commutation duty cycle value.

Abstract: A rotor position detecting circuit includes a first position detecting circuit having a low-pass filter that shapes up phase voltage induced in a phase coil and a first comparator that compares the output voltage of the low-pass filter with a threshold level to form a first rotor position signal, and a second position detecting circuit having a second comparator that compares the phase voltage with a threshold voltage and a control unit that digitally processes the output voltage of the second comparator to form a second rotor position signal. The control unit corrects the first rotor position signal by the second rotor position signal to provide a final rotor position signal when the rotation speed of the brushless DC motor is in a measurable range.

Abstract: A triangle wave generator (4) measures the phase difference between a triangle wave (CA) and the rotor electrical angle (?m) during a first cycle in which the rotation rate of a rotor (7) is detected, and changes the frequency of the triangle wave (CA) when the value of the phase difference between the triangle wave (CA) and the rotor electrical angle (?m) exceeds a threshold value, thereby allowing rapid response to changes in rotor rotation when PWM control is performed.

Abstract: A motor speed control circuit includes: a voltage generating circuit configured to change either a reference voltage corresponding to a target rotation speed of a motor or a speed voltage corresponding to a rotation speed of the motor, according to a temperature, and output the reference voltage and the speed voltage, either one of which is changed; a comparison circuit configured to compare the speed voltage output from the voltage generating circuit with the reference voltage output from the voltage generating circuit; and a driving circuit configured to drive the motor so as to match a level of the speed voltage to a level of the reference voltage, based on a comparison result from the comparison circuit.

Abstract: A sensorless controlling apparatus for controlling a brushless motor includes a speed calculator for calculating speed of a rotor ?, an angle calculator for calculating rotor angle ? at a predetermined time interval, and an angle controller for calculating correction angle ?? based on the current value of a d-axis current (d-axis current value id), thereby controlling the rotor angle ?. The angle calculator uses the correction angle ?? calculated by the angle controller, the speed ? calculated by the speed calculator, a predetermined time, and the rotor angle ? calculated by the angle calculator at a predetermined time to calculate the rotor angle at the predetermined time interval. Thus, the rotor angle ? calculated by the angle calculator is converged on the true angle of the rotor.

Abstract: A motor driving circuit for controlling a current amount flowing through a motor coil includes: a comparator configured to output a comparison signal indicating a comparison result between a set current amount and a current amount based on an inputted set current signal according to the set current amount and a current signal according to the current amount flowing through the motor coil; a current control signal update circuit configured to update a current control signal for controlling the current amount flowing through the motor coil in a stepwise manner so that the current amount flowing through the motor coil is changed to the set current amount in a stepwise manner, based on the comparison signal outputted from the comparator; and a driving circuit configured to drive the motor coil based on the current control signal outputted from the current control signal update circuit.