Abstract: A motor controller (2) for an axial-gap motor (1), which has a rotor (3), two stators (4, 5) disposed on both sides of the rotor (3) in the axial direction, and armature windings (6, 7) wrapped around the stators (4, 5), includes a field current controller (43, 44) which adjusts the field current in the current supplied to the armature windings (6, 7) of at least one of the stators (4, 5) so as to restrain a thrust force acting on the rotor (3) in the axial direction of the rotor (3). This restrains the thrust force acting on the rotor (3) of the axial-gap motor (1).

Abstract: A device for controlling a polyphase rotating machine comprising a stator, a rotor, and sensors, the device being capable of receiving at least one first sensing signal (V, W, U) representing a position of the rotor relative to the stator and outputted from a first sensor (16; 18; 14), and a second sensing signal representing the position and phase-shifted relative to the first signal (V, W, U). The second signal is outputted from a second sensor. The control device comprises: means (K, R) for combining the first and the second sensing signals (U, V, W) into a combined signal (Ku; Kv; Kw) including at least one controlled switching signal with a variable cyclic ratio. The combined signal (Ku; Kv; Kw) is based on the cyclic ratio and enables the machine to be controlled.

Abstract: An apparatus for controlling a fan motor of an air conditioner comprises: a hybrid induction motor (HIM) for discharging warm air outwardly by a control signal; a temperature detecting unit for detecting a temperature of an evaporator; and a controlling unit for comparing the temperature of the evaporator with a preset temperature, and outputting a control signal to control the HIM based on a result of the comparison.

Abstract: When the fan inserted in the fan header is a 4-pin fan, the control chip outputs PWM signals with different duty factors to the control pin of the fan header, to automatically change the rotary speed of the 4-pin fan. When the fan inserted in the fan header is a 3-pin fan, the control chip outputs the PWM signals whose duty factor changes with temperature of a chip under the fan to control the first power source to provide a voltage to the adjusting circuit. The adjusting circuit rectifies the voltage output from the first power source as an analog voltage signal to the control circuit. The control circuit controls the third power source to output a changeable driving voltage to the power pin of the fan header to control the rotary speed of the 3-pin fan.

Abstract: The object is to provide an inverter system for a vehicle-mounted air conditioner capable of reducing standby power requirements during nonuse. The voltage supply from a communication power source 80 is turned on and off on the basis of a signal from a communication driver 27a and an electric switch is changed over, whereby the voltage supply from a vehicle-mounted battery power source 50 to a DC-DC converter 26 is turned on and off and the voltage supply to a motor-control microcomputer 24 and a gate circuit 22 is turned on and off. As a result of this, during nonuse the operating state of the motor-control microcomputer 24 is shifted to a sleep mode by performing control by a host ECU 60, whereby the voltage supply is suspended and it becomes possible to reduce power consumption.

Abstract: A motor control device is disclosed which is arranged so as to perform a PWM control for a permanent magnet motor including a rotor having a permanent magnet and a stator with a multiphase winding. The motor control device includes a position detection unit which executes an analog computation process for induced voltages of respective phases of the motor based on a phase voltage equation having, as operation terms, respective phase voltages, respective phase currents, winding inductance, winding resistance and a neutral point voltage, the winding inductance and the winding resistance being motor constants of the motor, thereby generating and delivering a rotational position signal of the rotor based on a phase relation of the induced voltages, and a digital processing unit which has a function of generating and delivering a sinusoidal PWM signal based on the rotational position signal, thereby controlling the motor.

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 motor control device for controlling a d-axis current and a q-axis current on dq coordinates to control a motor, includes a q-axis current command value setting unit which sets a q-axis current command value, an upper limit/lower limit setting unit which sets an upper limit and a lower limit of the q-axis current, a comparing unit which compares the q-axis current command value set by the q-axis current command value setting unit and the upper limit and the lower limit set by the upper limit/lower limit setting unit, a q-axis current command value limiting unit which puts a limit on the q-axis current command value in accordance with a comparison result by the comparing unit, and a d-axis current command value setting unit which sets a d-axis current command value on the basis of the q-axis current command value limited by the q-axis current command value limiting unit.

Abstract: A controller for an AC rotary machine, by which a stable rotation angular-frequency estimate (AFE) value can be obtained even in an extremely low speed region of the AC rotary machine is disclosed, and consequently stable control can be performed. The controller includes an AFE outputter that outputs an AFE value based on an angular-frequency calculated value including a rotation AFE value. The AFE outputter includes a lower-limit constant-value (LLCV) outputter that outputs a LLCV, a comparator that compares the angular-frequency calculated value to the LLCV, and a switcher that performs a switching operation according to the comparator. The switcher outputs the angular-frequency calculation value as the AFE value when the angular-frequency calculation value is larger than the LLCV, and outputs the LLCV as the AFE value when the angular-frequency calculation value is equal to or less than the LLCV.

Abstract: A controller of a multi-phase electric motor includes a drive section for driving the multi-phase electric motor, a single current detection section for detecting a current value of the multi-phase electric motor, a pulse width modulation signal (PWM) generation section for generating a PWM signal of each phase based on the current value detected by the current detection section and a saw-tooth signal having a predetermined frequency, a current detectability determination section for determining whether or not the current value is detectable in the current detection section based on the PWM signal of each phase generated by the PWM signal generation section, and a switching number determination section for determining whether or not conducting number of the upper arm switching element is an even number or an odd number based on the determination that the current is not detectable by the current detectability determination section.

Abstract: An inexpensive, productivity-enhanced single-phase AC synchronous motor in which stabilized synchronous pull-in can be carried out by suppressing generation of counter torque during a starting operation. Starting operation is performed while the energizing range of motor current is suppressed such that the energizing direction of motor current waveform lagging in a phase behind the output waveform from a detection sensor (17) is switched at at least the zero cross point of the output waveform from the sensor when the number of revolutions of a permanent magnet rotor (1) reaches a predetermined number of revolutions in the vicinity of the synchronous number of revolutions.

Abstract: A motor control device includes a sensing circuit, a phase-shifting circuit, a comparing circuit and a control circuit. The sensing circuit senses the motor to generate a sensing signal. The phase-shifting circuit is electrically connected to the sensing circuit and receives the sensing signal to generate a phase-shifting signal. The comparing circuit is electrically connected to the phase-shifting circuit and receives the phase-shifting signal to generate a comparing signal. The control circuit is electrically connected with the comparing circuit and the motor, and receives the comparing signal to generate a control signal so as to control the rotation speed of the motor.

Abstract: In order to determine the orientation of the rotor of a brushless DC motor 100, a sequence of current pulses may be applied to the stator phases U, V, W by the respective drivers HS0, LS0, HS1, LS1, HS2, LS2. The current generated in the stator phases U, V, W in turn generates a current in a shunt resistor 110. The current in this shunt resistor 110 is monitored by use of a current voltage converter 120 and a comparator 130 to determine when it exceeds a predetermined threshold. The rise time until the threshold current is exceeded is recorded in capture unit 140. A processor unit 150 then calculates a scalar parameter SU, SV, SW for each respective stator phase U, V, W from the recorded rise times associated with each pulse.

Abstract: A field-oriented control method for an electric drive comprising a plurality of electric motors, for implementing a tension mechanism, especially for load cable and/or gearing means, using measurements of a polyphase motor actual current. The measured values are transformed into a direct current component and a quadrature current component, based upon a magnetic rotor field or flux angle, in a rotor flux-based d,q coordinate system. The quadrature and direct current components from the actual current are subjected to a comparison with predetermined quadrature and direct current components of a current command value.

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 commutation circuit for driving a brushless DC motor is controlled according to a commutation cycle composed of alternating primary steps and transitional steps. The commutation circuit includes pairs of field effect transistors coupled in series between the high voltage and low voltage terminals of a DC power supply. Output terminals between each pair of transistors are individually coupled to the phases of a DC motor. A controller operates the commutation circuit to selectively set the phases at active and inactive states. The controller further employs a plurality of voltage control functions individually associated with the motor phases to selectively modulate the voltage applied to one of the phases during the active states, to provide transitional steps in the commutation cycle during which the applied voltage is modulated to reduce its magnitude with respect to the high voltage or the low voltage.

Abstract: A device for controlling a polyphase rotating machine, the machine comprising a stator, a rotor, and sensors, the device being capable of receiving: at least one first sensing signal (U; V; W) representing a position of the rotor relative to the stator and output by a first sensor; and a second sensing signal (V; W; U) representing the position and phase-shifted relative to the first signal and output by a second sensor. The control device comprises: means (K, R) for combining the first and second sensing signals into a combined signal, the means including at least one controlled switching element capable adopting at least in two states, the combined signal being based on a state of the first element and enabling the machine to be controlled.

Abstract: The invention includes a motor controller and method for controlling a permanent magnet motor. In accordance with one aspect of the present technique, a permanent magnet motor is controlled by, among other things, receiving a torque command, determining a normalized torque command by normalizing the torque command to a characteristic current of the motor, determining a normalized maximum available voltage, determining an inductance ratio of the motor, and determining a direct-axis current based upon the normalized torque command, the normalized maximum available voltage, and the inductance ratio of the motor.

Abstract: Methods and systems for detecting an angular position of an electric motor are disclosed, including sending an electrical pulse through a stator coil of the electric motor, determining an approximate angular position of a rotor of the electric motor in response to detecting an timing of a returning electrical pulse from the stator coil, the timing of the returning electrical pulse being indicative of the angular position of the rotor; and determining an accurate position of the rotor in response to sensing a transition of a digital sensor in response to the rotor rotating relative to the stator, the transition being indicative of the accurate position.

Abstract: A method of constant airflow control 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.

Abstract: Embodiments of the invention provide a fire-extinguishing system and method for injecting foamant into a stream of water. The system can include a flow meter determining a flow rate of the stream of water and a foam pump having an inlet coupled to a supply of foamant and an outlet coupled to the stream of water. The system includes a servo motor driving the foam pump. The servo motor includes a sensor used to determine a rotor shaft speed and/or a rotor shaft torque.

Abstract: A system of computer fan control reduces vibration values and prominence ratios of a number of computer fans. A control chip outputs a phase setting control instruction to a PWM chip. The PWM chip outputs a number of out-of-phase PWM signals to rotate the number of computer fans according to the phase setting control instruction.

Abstract: A disk drive system including retract logic for control of the voice coil motor in a retract operation, in which the voice coil motor positions the read/write head actuator arm in a safe place in a loss-of-power event, is disclosed. The retract logic includes circuitry for controlling the application of power to the voice coil motor from an external capacitor, so that a constant voltage is maintained across the voice coil motor. Current from the capacitor is directed to an internal variable resistor that conducts a selected current, in parallel with the current applied to the voice coil motor. The voltage developed across the variable resistor is applied to one input of a control amplifier, which receives the voltage across the voice coil motor at another input; the control amplifier in turn controls the gate of a low side transistor. The transistor passes current to the extent that the voltage across the voice coil motor corresponds to that developed across the variable resistor.

Abstract: Method and system for motor oscillatory state detection. According to various embodiments, the present invention presents a method for determining whether a motor is in an oscillatory state. The method includes powering up a motor for a period of time and then monitoring the movement of the motor during a period after the power if turned off. Based on the movement of the motor and/or impeller during a time period after the power is turned off, whether the motor is in an oscillatory state is determined. The method also includes initiating a process for handle error if the motor is in the oscillation state.

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: An angle computing section determines an angle of a rotor, and an angular velocity computing section determines angular velocity of the rotor. A command current computing section determines, from a steering torque and vehicle velocity, command currents and taken along d-q axes. An open loop control section determines, from command currents and angular velocity, command voltages taken along the d-q axes in accordance with motor circuit equations. A d-q axis/three-phase conversion section converts the command voltages into command voltages of three phases. A ? computing section determines the number of armature winding flux linkages included in a motor circuit equation from a q-axis command voltage, the current value detected by a current sensor, and the angular velocity. Circuit resistance including armature winding resistance R included in the motor circuit equation may also be determined by means of the same configuration.

Abstract: A position observer for control-based torque ripple mitigation in permanent magnet synchronous machines (PMSMs). Rotor position is determined using data from two sources: a piezoelectric sensor for initial position and low-speed detection, and a single Hall-effect sensor for high-speed detection.

Abstract: The Brushless Multiphase Self-Commutation Controller or BMSCC is an adjustable speed drive for reliable, contact-less and stable self-commutation control of electric apparatus, including electric motors and generators. BMSCC transforms multiphase electrical excitation from one frequency to variable frequency that is automatically synchronized to the movement of the electric apparatus without traditional estimation methods of commutation and frequency synthesis using derivatives of electronic, electro-mechanical, and field-oriented-control. Instead, BMSCC comprises an analog electromagnetic computer with synchronous modulation techniques to first establish magnetic energy and then dynamically share packets of magnetic energy between phase windings of a multiphase, position dependent flux, high frequency transformer by direct AC-to-AC conversion without an intermediate DC conversion stage.

Abstract: A motor control device includes: an electric circuit that supplies power, which is supplied from a power source and controlled by the electric circuit, to a motor; and a control circuit that generates a command signal to be used to control operation of the electric circuit, wherein: the control circuit generates the command signal so as to intermittently turn off power supply to the motor while the motor is being driven with power supplied to the motor and controls operation of the electric circuit based upon the command signal thus generated.

Abstract: A motor device comprising a motor, and a drive control circuit for driving and controlling the motor, in which the drive control circuit includes a control unit for generating a control signal for controlling the rotation of the motor, a drive unit for driving the motor on the basis of the control signal, and a communication unit for making serial communications via a serial communication bus for transmitting serial data. This communication unit has an address generating function for generating and setting addresses.

Abstract: A two-stranded electronically commutated DC motor has a permanent-magnet rotor (36), power supply terminals (28, 30) for connecting the motor to a current source (22) and a stator (102) having a winding arrangement which includes first and second winding strands (52, 54). The latter are controlled by respective first and second semiconductor switches (70, 80). The motor also has a third controllable semiconductor switch (50), arranged in a supply lead from one of the terminals (28, 30) to the winding strands (52, 54), which third switch is alternately switched on and off by applying to it a PWM (Pulse Width Modulated) signal 24. During switch-off intervals, magnetic flux energy stored in the motor causes a decaying loop current (i2) to run through the windings, continuing to drive the rotor. This facilitates conformal mapping of temperature information in the PWM signal onto a target motor rotation speed.

Abstract: A first member has a magnet assembly that includes at least one permanent magnet pair, and a second member includes an electromagnetic coil. A control circuit controls the supply of power to the electromagnetic coil as well as regeneration of power from the electromagnetic coil. The permanent magnet pair generates its strongest magnetic field along a magnetic field direction on homopolar contact planes where first magnetic poles contact one another, outward from the center of the permanent magnet pair along the magnetic field direction. The electromagnetic coil is positioned such that current will flow in a direction intersecting the magnetic field direction.

Abstract: A controller of a brushless DC electric machine having a rotor and at least a stator winding powered by a driving voltage is provided. The controller includes a position sensor, an advance angle control circuit, and a driving circuit. The position sensor is moved along a reverse rotating direction of the rotor by a prepositioned angle for outputting a position signal. The advance angle control circuit receives the position signal and a driving voltage reproduction signal reproduced from the driving voltage and outputs a commutation control signal lagging the position signal by a first delay time. The driving circuit receives the commutation control signal for outputting a driving signal for controlling a commutation of the brushless DC electric machine.

Abstract: A control device of a boost converter which includes: an inverter circuit which controls switching to apply current to a stator winding of respective phases of a multi-phase brushless DC motor; and a boost circuit which is provided on an input side of the inverter circuit and has at least a reactor and a switching element, and controls ON and OFF states of the switching element of the boost circuit on the basis of a boost voltage command which is a command for boost voltage output from the boost circuit, the control device is provided with a boost voltage command setting unit which sets the boost voltage command on the basis of counter electromotive voltage of the brushless DC motor and a torque command for the brushless DC motor.

Abstract: The present invention provides an electronic commutator circuit for use with a stator winding of an electrical machine. The stator winding of the electrical machine includes a number of coils linked by the same number of points of common coupling. The electronic commutator circuit comprising the same number of switching stages, each switching stage being connected between a respective one of the points of common coupling and first and second dc terminals. Each switching stage further includes a first reverse blocking semiconductor power device (such as a Reverse Blocking Gate Turn Off Thyristor (RB-GTO 1) capable of being turned on and off by gate control having its anode connected to the first dc terminal, and a second reverse blocking semiconductor power device (RB-GTO 2) capable of being turned on and off by gate control having its cathode connected to the second dc terminal.

Abstract: When starting a brushless motor, if the stop position of the rotor is detected between time t1 and time t2, a start-up excitation pattern in accordance with the rotor stop position is input for an initial energization time Ts1. Afterward, when the energization is stopped, a plurality of signals SL1, SL2, SL3, SL4 are generated in sequence in excitation switch timing signals in accordance with the rotational position of the coasting rotor. From these signals SL1 to SL4, the rotor position is detected using the second and subsequent signals SL2 to SL4 and then the process shifts to ordinary energization switch control. In accordance with the present invention, it is possible to start up a motor in a short time with a simple method so as to obtain a large torque during start-up.

Abstract: A permanent magnet rotor for use in a flux regulated permanent magnet brushless machine is constructed such that the inductance along the direct and quadrature axes is markedly different to provide sensorless position feedback for the rotor.

Abstract: A drive system for an electrical machine is provided. The system includes a control unit and a monitoring unit, which is independent of the control unit. The control unit includes a device that converts one or more incoming operating parameters of the electrical machine to an output value. The monitoring unit includes a device that converts the operating parameters to a comparison value, with the conversion being carried out more quickly in the control unit than in the monitoring unit. A comparator compares the output value or an intermediate value of the output value with the comparison value of the output value or of the intermediate value.

Abstract: A temperature estimation controller and methods are provided for controlling a torque command to prevent overheating of one or more of a plurality of phases of a permanent magnet motor. The temperature estimation controller includes a low speed temperature estimation module, a transition module and a temperature dependent torque command derater block. The low speed temperature estimation module determines a stator temperature of each of a plurality of phases of the permanent magnet motor in response to first thermal impedances measured for each of the plurality of phases with respect to a thermal neutral. The transition module is coupled to the low speed temperature estimation module and outputs the stator temperature of each of a plurality of phases of the permanent magnet motor as determined by the low speed temperature estimation module when a detected speed of the permanent magnet motor is less than a first predetermined speed.

Abstract: A method of controlling a brushless DC motor of the type having a stator, comprising a stator winding excitable to generate a stator magnetic field, and a rotor, arranged to rotate with respect to the stator and comprising permanently magnetized material arranged to generate a rotor magnetic field to interact with the stator magnetic field to produce rotation of the rotor. The method comprises the steps of driving current through the stator winding to generate a stator magnetic field to interact with the rotor magnetic field, detecting rotor position with respect to the stator, and cyclically commutating the stator winding current according to rotor position as the rotor rotates. Each commutation cycle includes a drive portion during which current is driven through the stator winding in one sense and at the end of which the driving of current in said sense is ceased.

Abstract: A protecting device of a fan system includes at least one first switch element and at least one control unit. The first switch element receives a first input signal. The control unit is electrically connected with the first switch element, receives the first input signal, and controls the first switch element to turn on or turn off according to the first input signal. The control unit stops outputting the first input signal when the first switch element turns on. The control unit outputs the first input signal when the first switch element turns off, so that a fan of the fan system can be driven by the first input signal.

Abstract: The brushless motor includes a coil array, a magnet array, a magnetic sensor, a drive control circuit for driving the coil array, and a temperature sensor for detecting a detection target temperature associated with either the coil temperature or the driving element temperature. The drive control circuit reduces the effective value of driving voltage supplied to the coil array when coil temperature detected by the temperature sensor has exceeded a prescribed threshold value.

Abstract: A driving apparatus for fan motors, electrically connected between a pulse width modulation (PWM) signal generator and a controller, includes a converter electrically connected to the PWM signal generator, generating a first reference voltage according to the duty cycle of a PWM signal generated by the PWM signal generator; a reference voltage generator electrically connected to an external power source, generating a second reference voltage according to the external power source; and a comparator having a first and second input terminal and an output terminal; wherein the first input terminal is electrically connected to the converter, the second input terminal is connected to the reference voltage generator and the output terminal is connected to the controller, and when the first reference voltage is greater than the second reference voltage, a driving signal is output from the output terminal to the controller to control the rotation speed of the fan motor.

Abstract: A power tool may include an electronically commutated motor such as, for example, a brushless DC permanent magnet motor with a rotor having internally mounted magnets and/or cavities filled with air or other non-magnetic materials. A control system may be used to control the motor in a manner that implements field weakening when the speed of the motor increases beyond its rated motor speed, or when the torque demands on the motor continue to increase after the maximum power output of the motor is reached. The field weakening may offset the growing back EMF and may enable a constant power and constant efficiency to be achieved by the motor over a wide speed range, rather than at just a single predetermined operating speed. Pulse width modulation control of the motor may be used up until the motor reaches its maximum power output.

Abstract: A supply current control circuit controls the voltage of a low-voltage direct-current power source so that the average current of an inverter circuit detected by a current detecting circuit becomes constant at a specified current value. Accordingly, characteristics that are little in the amount of change of air volume are obtained.

Abstract: A brushless, liquid or air cooled, direct current motor formed from a three stack stator and three section rotor assembly using an integrated water cooled or air cooled housing and over-molding techniques.

Abstract: A power converter circuit for providing maximum utilization of a DC bus voltage to a two-phase Permanent Magnet Synchronous Motor (PMSM) is disclosed. The circuit includes first, second, and third nodes, each node being the junction between series connected high and low side switches connected across a DC bus; a PMSM having first and second windings and a star point at which the first and second windings are coupled to each other, the first winding having a terminal connected to the first node, the second winding having a terminal connected to the second node, and the star point being connected to the third node; and a controller for performing a three-point Pulse Width Modulation (PWM) coupled to a gate of each switch.

Abstract: In a driving system for an inverter that uses a diode rectifying circuit to convert a single-phase or three-phase AC voltage to a desired DC voltage and drives a permanent magnet motor, a DC-voltage pulsating frequency is estimated from a pulsating frequency setting calculated from the power supply frequency of an AC voltage and the detected current values of the inverter, and the resulting estimated pulsating frequency value and detected current values are used to correct the output voltage of the inverter.

Abstract: The invention teaches a speed control system for a brushless DC motor for a ceiling fan, comprising a power circuit 1, a microprocessor circuit 2, a power drive circuit 3, a speed regulation circuit, and a brushless DC permanent magnetic motor 5, wherein the input terminal of the power circuit 1 is connected to the output terminal 101 of an AC power source, the output terminal of the power circuit 1 serves to power the various circuits, the output terminal of the microprocessor circuit 2 is connected to the input terminal of the power drive circuit 3, the output terminal of the power drive circuit 3 is connected to the coil windings 501 of the brushless DC permanent magnetic motor, and the output terminal of the speed regulation circuit is connected to the input terminal of the microprocessor circuit 2. The speed control system of the invention provides the advantages of low energy consumption, low noise during the operation of the motor, and a stable operation at low speeds.

Abstract: Disclosed is a realization method of a speed signal of a motor using a linear Hall-effect sensor that may include the steps of: determining coordinate values on a x-y coordinate system using a Hall signal in the form of a sine wave of a linear Hall-effect sensor, evaluating a summed coordinate value of the above coordinate values, calculating the angle (?) formed by a summed coordinate value and the x axis; determining the quadrant of the resulted angle (?), and determining a speed signal by dividing the final motor displacement value by the rate of time change.