Abstract: Systems for controlled resonance in electrical power devices are described. A programmed signal processor generates output control signals from input electrical signals based on resonant control parameters for a target power device. Analog electrical control systems for controlled resonance, power devices incorporating controlled resonance, and opto-programmed controllers for use in controlled resonance applications are described, with example embodiments for electro-mechanical systems with resonant constructive power drive action for electric motors.

Abstract: According to one embodiment, an inverter controller includes a current controller which calculates and output PWM modulation ratio instructions of a first phase and a second phase, such that an inverter outputs a predetermined current; a switching timing arithmetic unit which calculates timings at which switches of the respective phases are opened and closed; a simultaneous switching avoiding unit which determines whether a first switching timing for changing over the switch of the first phase and a second switching timing for changing over the switch of the second phase coincide or not, and to generate, upon determining that the first switching timing and the second switching timing coincide, triangular-wave carriers of the first phase and the second phase by making different waveforms of the triangular-wave carriers; and a switch opening/closing timing generator which calculates a timing for opening/closing the switch.

Abstract: One embodiment describes a method that includes, when a motor is disconnected from a power source: starting, using a control circuitry, a counter at a first voltage zero-crossing by either a source voltage or a back electromotive force generated by the motor; stopping, using the control circuitry, the counter at a next subsequent second voltage zero-crossing by either the source voltage or the back electromotive force; monitoring, using the control circuitry, a trend in counter values; and instructing, using the control circuitry, one or more switching devices to reconnect the power source to the motor after a local minimum in the counter value trend such that the source voltage is leading the back electromotive force.

Abstract: In accordance with an embodiment, a drive circuit is provided for driving for a motor wherein the drive circuit includes a first signal generator coupled to a second signal generator. A bias generator is connected to the second signal generator. In accordance with another embodiment, a method for driving a motor is provided that includes comparing a first signal at a first output of a Hall sensor with a second signal at a second output of the Hall sensor to generate a comparison signal. An indicator signal is generated in response to the comparison signal, wherein the indicator signal has a first edge and a second edge. A bias signal for the Hall sensor is generated in response to the indicator signal in response to the indicator signal.

Abstract: The electric motor control device includes: an inverter circuit 20 which converts DC power of a DC power supply 90 into AC power; and a switching control section 60 which performs on/off control of a semiconductor switching element composing the inverter circuit. The switching control section 60 includes: a power-supply-side abnormality determination section 62 which determines whether a power-supply-side abnormal state is established in which regenerative energy from an electric motor 10 cannot be regenerated to the DC power supply; and a switching frequency changeable section 63 which changes, when the power-supply-side abnormality determination section has determined that the power-supply-side abnormal state has been established, a switching frequency of the semiconductor switching element such that an overall loss, which is a total of loss in the inverter and loss in the electric motor, is increased.

Abstract: A power conversion apparatus includes a power converter to directly convert AC power having a frequency into AC power having a different frequency. A gate driver drives the power converter. A gate drive signal generator generates a gate drive signal supplied to the gate driver. Two cutoff devices are coupled between the gate driver and the gate drive signal generator, and supply or cut off the gate drive signal to the gate driver based on a command from an external apparatus. At least one of the two cutoff devices generates a feedback signal. An analyzer determines whether the one cutoff device has an abnormality based on the command and the feedback signal. A cutoff controller controls another one of the two cutoff devices to cut off the gate drive signal to the gate driver when the analyzer determines that the one cutoff device has the abnormality.

Abstract: Provided are a power conversion device control device and a power conversion device control method, which are capable of reducing harm to other electronic devices and electromagnetic noise due to a switching frequency compared to the related art. Carrier change patterns of the respective phases, which are defined by parameters of an average switching frequency, a spectral diffusion index, and a repetition frequency, are generated so that at least the carrier change pattern of one phase differs from the carrier change patterns of the other phases. Semiconductor switching elements are controlled as instructed by duty command values while the switching frequency is switched for each phase separately, from one frequency to another sequentially based on carriers output in patterns that follow the generated carrier change patterns.

Abstract: In a control apparatus, an interference-reduction current calculator calculates, as an interference reduction current, a component of a current vector in a coordinate axis in a rotating coordinate system defined with respect to a rotor of the rotary machine. The current vector flows in the rotary machine, and the coordinate axis serves as an interference reduction coordinate axis in which the component of the current vector has reduced interference from change of the phase of the output voltage vector. An amplitude setter sets, as a manipulated variable for feedback controlling the interference reduction current to a command current value based on a command value for a controlled variable, one of: an amplitude of the output voltage vector, and an amplitude parameter indicative of a component of the output voltage vector. The component of the output voltage vector depends on the amplitude of the output voltage vector.

Abstract: Current sensing circuitry for sensing a current through a load comprises an adaptive-resistance sensor component arranged to be operably coupled in series with the load, and control logic for controlling a resistance of the adaptive-resistance sensor component. The control logic is arranged to receive a signal representative of a voltage across the adaptive-resistance sensor component, compare the received signal to a reference value that is representative of a determined voltage, and in response to the comparison control the resistance of the adaptive-resistance sensor component, such that the voltage across the adaptive-resistance sensor component substantially tracks the determined voltage value.

Abstract: Electric circuit for estimating the angular position of a rotor of an electric motor, including: a sensing module configured to receive at least one electric signal representative of a drive current of the electric motor and to generate a measurement signal indicative of a switching of the at least one electric signal and a switching index indicative of the type of switching, rising or falling, of the at least one electric signal; and a computing module configured to supply, from the measurement signal and switching index a position signal representative of an angular position of the electric motor rotor.

Abstract: Two magnetic poles of a permanent magnet of a permanent magnet switch and the two ends of an iron core wound with an excitation coil are connected to each other with the soft magnet having a salient pole. A motor uses the switch as the basic component of the stator and rotor, with two magnetic salient poles of each component being arranged axially, wherein the salient pole of the stator component and that of the rotor component are arranged in an opposite manner with an air gap, the excitation coil of the stator component and the rotor component at the symmetric axis position is taken as a phase line to access an excitation control power supply after serial connection or parallel connection. Electric excitation is carried out on the combined motor formed by shaft connection and rotation dislocation among single motors and the stator component in a bi-phase way simultaneously.

Abstract: If a bus current a bus current detector 11 detects exceeds a current cutoff value, an overcurrent detector 12 supplies a gate driver 14 with an open signal for turning off switching elements 5-10 to break the current to a motor 1. Besides, when the overcurrent detector 12 detects an overcurrent, a feedback controller 15 provides the gate driver 14 with a short-circuit braking instruction to apply short-circuit braking after breaking the power supply, and to restart PWM control from a state in which the short-circuit braking is being applied and the duty ratio command value is reset at 0.

Abstract: Motor drive device (30) according to the present invention includes operation pattern generator (1), position and speed controller (23), load characteristic compensator (24), and load characteristic measurement unit (7). Operation pattern generator (1) increases an absolute value of acceleration, at which a motor speed or a motor position is changed, in each operation pattern. Load characteristic measurement unit (7) measures the load characteristic to set load characteristic compensator (24) when torque command indicator is less than or equal to a torque limit value. Load characteristic measurement unit (7) ends the measurement of the load characteristic without setting load characteristic compensator (24) when the torque command indicator is greater than the torque limit value.

Abstract: A method of driving a permanent magnet synchronous electric motor includes sensing or estimating a back electromotive force induced in at least a winding of the motor by the rotation of a rotor of the motor; and reading, from a memory, values of a first voltage waveform having a phase angle with respect to the back electromotive force. The method also includes generating a driving voltage corresponding to the sum of values of a control voltage, obtained as product of the values of the first voltage waveform by a first coefficient determined as a function of a desired value of motor torque, and values of a cancelation voltage of the back electromotive force. The method also includes applying the driving voltage at the motor winding.

Abstract: A motor controller that controls energization of a motor in which a plurality of coils U1 to W2 that applies torque to a rotor is arranged in a circular pattern includes: a rotation speed detection sensor that detects a rotation speed of the motor; and an energization control unit that controls energization of the plurality of coils U1 to W2 using the detected rotation speed. The energization control unit sequentially energizes the plurality of coils U1 to W2 in all energization patterns if the detected rotation speed is outside of predetermined conditions and sequentially energizes the plurality of coils U1 to W2 in remaining energization patterns (for example, U?V phase, V?W phase, V?U phase, W?U phase, and W?V phase) excluding a partial energization pattern (for example, U?W phase) of all energization patterns if the detected rotation speed is within the predetermined conditions.

Abstract: A motor driver apparatus that is formed of a semiconductor integrated circuit which is supplied with an electric power and drives a direct current motor includes a signal generating part that generates an indication signal for indicating a back electromotive force generation period while the direct current motor generates a back electromotive force, a removing part that detects a voltage variation generated in a power-supply voltage by the back electromotive force generated by the direct-current motor during the back electromotive force generation period indicated by the indication signal, and removes the detected voltage variation, and a limiting part that limits the power-supply voltage so as to be less than a predetermined voltage at a speed higher than that in the removing part.

Abstract: The invention relates to a method wherein the speed of the rotor of an electronically commutated synchronous machine is determined or controlled by means of one or more rotor position sensors, in particular, three rotor position sensors that are fixed to the stator, and a time measuring device, wherein the angle traveled by the rotor and the time lapsed during the travel are measured, wherein the measured angle traveled by the rotor is corrected by means of one or more first correction constants, in particular a differential for correcting for the influence of non-uniform positioning or expansion of the position marking of the rotor, and a circuit configuration for actuating an electronically commutated synchronous machine.

Abstract: A motor drive apparatus drives a motor generator using electric power provided from a DC power supply. The motor generator rotates a rotor provided with a permanent magnet using a current magnetic field generated by passing a drive current through a coil of a stator. The motor drive apparatus includes an inverter configured to convert DC electric power provided from the DC power supply into AC electric power for driving the motor generator. An ECU of the motor drive apparatus controls the inverter such that an offset current is superimposed on at least one phase of the coil of the stator and a temperature of the permanent magnet provided at the rotor is raised.

Abstract: The present disclosure provides a device and a method for driving a motor that demonstrates low noise and/or low vibration. A pulse-modulated control pulse signal S2 is generated by a driving signal generation portion 310 at each phase. A driving voltage VU˜VW, with duty cycle corresponding to the control pulse signal S2 and being inserted with specific idle time is applied to coils LU˜LW at each phase. A current phase detection signal S3 indicating a phase of the current IL flowing through the coil LU is generated by the current phase detection portion 330 at a specific phase (the phase U) corresponding to the control pulse signal S2 according to a pulse width of a terminal voltage VU at one end of the coil LU of the phase U.

Abstract: A circuit configuration for driving an electric motor includes a signal evaluation module, which stores a number of output patterns. An input pattern is specified, and as a function of the input pattern, one of the output patterns is output, by which the electric motor is driven.

Abstract: A drive system, for a multi-phase brushless electric motor comprising a plurality of phases, comprises: a drive circuit including switch means arranged to vary the phase voltage applied to each of the phases so as to switch the motor between a plurality of active states; and control means. The control means is arranged to control the switch means so as to provide PWM control of the phase voltages to control the mechanical output of the motor. The control means is arranged to define a sequence for all of the active states and, for each PWM period, to allocate state times for the states required for that period to generate a desired net voltage, and to order the required states in the same order as they occur in the sequence.

Abstract: A motor constant calculating method for a PM motor according to the present invention includes a voltage applying step of applying an applied voltage including a DC component and a plurality of frequency components to a PM motor, a motor current detecting step of detecting a motor current flowing depending on the applied voltage applied in the voltage applying step, and a motor constant calculating step of calculating a motor constant of the PM motor based on the applied voltage and the motor current.

Abstract: A carrier generating unit applies a carrier that monotonically decreases to a switching control unit during either one of a first period that is a period immediately following a period in which a voltage command value is a value not more than a minimum value of the carrier, the voltage command value taking a first predetermined value larger than the minimum value of the carrier in the first period, and a second period that is a period immediately preceding a period in which the voltage command value is not less than a maximum value of the carrier, the voltage command value taking a second predetermined value smaller than the maximum value in the second period.

Abstract: The present invention provides a method for driving a three-phase motor with a driver. The driver can provide a pulse-width modulated driving signal and a linear driving signal. The three-phase motor has a first leg, a second leg and a third leg. The method includes: connecting the second leg to the driver; floating the third leg; driving the second leg with the pulse-width-modulated driving signal from the driver; estimating a time when a voltage in the third leg will reach a predetermined threshold; and driving the second leg with the linear driving signal during that time.

Abstract: There are provided a pulse width modulation (PWM) signal generating circuit and a motor driving circuit. The PWM signal generating circuit includes: a proportional-to-absolute temperature (PTAT) voltage generating unit generating a PTAT voltage in proportion to an absolute temperature; a reference wave signal generating unit generating a preset reference wave signal; and a PWM signal generating unit comparing the PTAT voltage and the reference wave signal with each other to generate a PWM signal, wherein the PTAT voltage generating unit adjusts the PTAT voltage according to a control signal.

Abstract: The system and method disclose for the controlling of sequential phase switching in driving a set of stator windings of a multi-phase sensorless brushless permanent magnet DC motor. A motor controller controls a power stage that drives two windings of a set of three windings in the motor with pulse width modulated signal. A plurality of voltage values on an undriven winding of the set of three windings are sampled within a window of time, wherein a period beginning when the driven windings are energized and ending when the driven windings are de-energized encompasses the window of time. The sampled voltage values are processed. When the processed voltage values exceed a threshold, the motor controller changes which two windings are driven.

Abstract: A method and apparatus for controlling an electric motor. A controller is configured to identify a start time for a signal based on a back electromotive force present in an electric motor during operation of the electric motor. The start time is for a position of a rotor relative to a group of coils. The controller is further configured to send the signal to the group of coils using the start time identified. An effect of the back electromotive force on the signal is reduced.

Abstract: A motor driving device includes a clock oscillator configured to generate a clock signal; and a logic unit configured to receive the clock signal, control conduction of a 3-phase brushless direct current (DC) motor, and generate a revolutions per minute (RPM) detection signal. The clock oscillator is configured to switch an oscillation frequency of the clock signal depending on an RPM command signal input to set a target RPM of the 3-phase brushless DC motor.

Abstract: Single-phase voltage operation techniques are provided for a three-phase drive system. A drive system may include a rectifier configured to couple to a three-phase AC voltage source. The rectifier may be configured to convert AC voltage from the three-phase AC voltage source to a direct current (DC) voltage. The drive system may also include a controller configured to send a plurality of switching signals to a plurality of switches in the rectifier such that the plurality of switching signals minimizes a current provided to the rectifier when only a single-phase of the three-phase AC voltage source is available.

Abstract: A motor control device includes a PWM signal generation unit generating a signal pattern of two of three phases so that the pattern follows a rotor position, and a timing adjusting unit. The signal generation unit increases/decreases duty in both directions of lag side and lead side based on any phase of a carrier-wave period regarding a first phase. The signal generation unit increases/decreases duty in one direction regarding a second phase. The signal generation unit increases/decreases duty in a direction opposite to the second phase regarding a third phase. The timing adjusting unit adjusts detection timing so that a current detection unit detects current in fixed timing with respect to one phase and current in another fixed timing with respect to the other phase or the current detection unit is capable of detecting current in variable timing according to magnitude of output voltage to an inverter circuit.

Abstract: There is provided a motor driving apparatus capable of stably performing operation conversion between a normal mode and a sleep mode by counting a duty of the PWM signal according to a preset clock signal, the motor driving apparatus including: a pulse width modulation (PWM) signal generating unit providing a PWM signal for driving a motor; a driving unit operating normally in a normal mode and waiting for operation in a sleep mode according to a control, and driving the motor in response to the PWM signal of the PWM signal generating unit; and a driving controlling unit counting a duty of the PWM signal according to a preset clock signal to determine an operation mode of the driving unit.

Abstract: An electric motor (40) has a permanent-magnet rotor (46) and an apparatus for generating a three-phase sinusoidal current (i202, i204, i206) for supplying current to said motor (40), also a microprocessor (95) for executing the following steps: while the motor (40) is running at a substantially constant load, the motor is operated firstly at a predetermined operating voltage (U), and an amplitude of a current flowing to the motor is iteratively sampled, stored, and compared as applied voltage is decreased. If it is found, in this context, that the current flowing to the motor has not decreased as a result of reduction in the voltage amplitude, the motor (40) is operated at that current. If, however, it is found that the current flowing to the motor has decreased as a result of the reduction in the voltage delivered to the motor (40), the measurements and the comparison are repeated, optionally multiple times, in order to identify values for optimized efficiency.

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

Abstract: A control device of a three-phase AC motor includes: an inverter; a current sensor for a sensor phase current; and a controller switching a switching element of each phase of the inverter and having a current estimation device, which calculates a sensor-phase-standard current phase according to ? and ? axis currents and a current estimated value of another phase. The current estimation device calculates the ? axis current at every switching and intermediate timings, calculates a first differential value of the ? axis current at every switch timing, calculates the ? axis current according to the first differential value, calculates a second differential value of the ? axis current at every intermediate timing, and calculates the ? axis current according to the second differential value. The intermediate timing is set to have an unequal interval between two adjacent switch timings.

Abstract: A modularized control circuit with a signal-capturing function for a fan motor is disclosed. The modularized control circuit includes a driven circuit and a microcontroller integrated circuit. The driven circuit is electrically connected to the fan motor to produce at least one analog driven voltage signal, thus driving the fan motor. The microcontroller integrated circuit is electrically connected to the driven circuit and includes a signal-capturing module, a control unit, and a driven signal generator. The signal-capturing module receives an external pulse signal to produce a cycle-capturing signal. The control unit is connected to the signal-capturing module and receives the cycle-capturing signal to produce a control signal. The driven signal generator is connected to the control unit to receive the control signal, thus producing a plurality of switch driven signals for controlling the driven circuit.

Abstract: There are provided a circuit and a method for detecting a duty ratio of a PWM signal. The circuit includes: a counting unit counting a PWM signal; a detection indication determining unit determining whether a detection indication signal indicating a start of detection of the duty ratio of the PWM signal has been input; an edge detecting unit detecting a preset PWM edge of the PWM signal; and a duty calculating unit calculating the duty ratio of the PWM signal using a count value during a section from a k-th point in time (T(k)) (k being a natural number of 1 or more) at which the PWM edge is detected after it is determined that the detection indication signal has been input to a k+1-th point in time (T(k+1)) at which the PWM edge is detected after it is subsequently determined that the detection indication signal has been input.

Abstract: The present invention includes, a failure sensing part to sense the failure created in the encoder mode and sensorless mode to control the door; a main control part to convert the main operation part and backup control part mutually when a failure is sensed by the primary operation mode by the failure sensing part after deciding either of the encoder mode or sensorless mode as a primary operation mode and another one is decided as a backup operation mode; and a location/speed conversion part to perform the door control by calculating the door moving distance according to the corresponding mode when the operation mode is converted by the main control part.

Abstract: A data reception unit carries out reception of data, which consists of a combination of switching noise resistant states and switching noise nonresistant states, over a fixed serial communication time a plurality of times for each fixed serial communication period same as the one or a plurality of the switching periods. A serial communication time setting unit sets the serial communication time different from one or a plurality of the switching periods, based on the switching period, the serial communication period, and the communication speed of the data communication device, so that the starts of all of the switching periods within the serial communication time are consistent with the time of reception of the switching noise resistant state at the time of at least one of the reception of the data among a plurality of times of the reception of the data.

Abstract: There are provided an apparatus and a method for controlling a motor. The apparatus for controlling a motor includes a signal generation unit generating a first signal indicating position information of a rotor, a counter unit sampling the first signal with a second signal different from the first signal for one period to count a sampling frequency, a memory unit storing a section counter value and an error value obtained by sampling a period immediately prior to the first signal with the second signal, and a comparison unit increasing and reducing an output signal when the sampling frequency counted by the counter unit coincides with the section counter value, wherein the comparison unit sums the sampling frequencies corresponding to error values with the sampling frequency of the first signal before the counter unit ends the sampling of one period of the first signal.

Abstract: A motor controller includes an inverter portion having an upper switching element and a lower switching element which are connected in series, and an inverter control portion generating control signals and controlling a drive of each switching element. The inverter control portion generates the control signals such that (i) different phases of the upper switching element and the lower switching element are synchronously energized and intermittently turned on, (ii) a pulse-width modulation period of the upper switching element is equal to a pulse-width modulation period of the lower switching element, (iii) an on-period of one of the upper switching element and the lower switching element is greater than an off-period of the other one of the upper switching element and the lower switching element, and (iv) the off-period is in a time period from a time point the on-period starts to a time point the on-period completes.

Abstract: A delay circuit for a fan includes a signal generation circuit, a first switch, a delay microchip, and a second switch. The signal generation circuit receives a driving signal and generates a control signal according to the driving signal. The first switch is electronically connected to the signal generation circuit to receive the control signal. The second switch is electronically connected between the delay microchip and the fan. When the signal generation circuit is electronically connected to the fan via the first switch, the control signal is transmitted to the fan to activate the fan. When the signal generation circuit is electronically connected to the delay microchip, the delay microchip receives the control signal and outputs a delayed control signal after a predetermined delay time, and the delayed control signal is transmitted to the fan via the second switch to activate the fan.

Abstract: A converter control device comprises: a voltage-zero-cross detection unit detecting zero cross of the alternate-current voltage and outputting a voltage zero-cross signal; a power-source-current detection unit detecting a power source current of the alternate-current power source; a bus-line-voltage detection unit detecting a bus-line voltage between terminals of the smoothing capacitor; a PWM-signal generation unit generating a PWM-signal for on/off-controlling the switching unit, based on the power-source current, the bus-line voltage and a bus-line-voltage command value as a target voltage of the bus-line voltage; a power-source voltage-state detection unit detecting a signal state of the alternate-current voltage based on the voltage zero-cross signal; and a fundamental-switching-frequency selection unit selecting a fundamental switching frequency of the PWM-signal based on the signal state of the alternate-current voltage.

Abstract: An apparatus for measuring a position deviation of a rotor of a permanent magnet synchronous motor includes a control unit, a power transformation unit, a rotor position estimator and a calculation unit. The control unit receives a d-axis DC voltage signal and a q-axis AC voltage signal and receives an initial value of the rotor position and a high-frequency signal to output a three-phase command signal. The power transformation unit receives the three-phase command signal and outputs a three-phase control signal for controlling the motor. The rotor position estimator receives a three-phase current feedback signal corresponding to an operation of the motor and generates an estimation value of the rotor position. The calculation unit performs calculation to the initial value and the estimation value to generate a deviation value of the rotor position. Moreover, a method for measuring the position deviation is also disclosed herein.

Abstract: A method of controlling a brushless motor that includes rectifying an alternating voltage to provide a rectified voltage, exciting a winding of the motor with the rectified voltage and freewheeling the winding when current in the winding exceeds a threshold. The winding is freewheeled for a freewheel period, which is updated in response to a zero-crossing in the alternating voltage. Additionally, a control system that implements the method, and a motor system that incorporates the control system.

Abstract: According to typical examples, the first stator winding having the lower rated voltage is connected to the second direct-current voltage source only when the rotation speed of the rotating electrical machine becomes high. Therefore, output in a high-rotation range can be ensured while preventing the second stator winding from reaching a heat-generation limit. Furthermore, such switching operations can be actualized by the first switch and the second switch. Therefore, a control device of a rotating electrical machine can be actualized by a relatively simple configuration.

Abstract: A method of controlling a brushless permanent-magnet motor. The method includes commutating a winding of the motor at times that are retarded relative to zero-crossings of back EMF in the winding.

Abstract: A controller for a brushless motor that includes a PWM module configured in half-bridge or full-bridge mode. The PWM module outputs control signals for controlling the excitation of a winding of the motor, and one of the duty cycle and the period of the PWM module defines a time at which the winding is commutated.

Abstract: A method of controlling a brushless permanent-magnet motor. The method includes dividing each half of an electrical cycle of the motor into a conduction period followed by a primary freewheel period. The conduction period is then divided into a first excitation period, a secondary freewheel period, and a second excitation period. The method then involves exciting a winding of the motor during each excitation period and freewheeling the winding during each freewheel period. The secondary freewheel period has a position and length within the conduction period that acts to reduce the harmonic content of current in the winding relative to back EMF in the winding. As a result, the efficiency of the motor is improved.

Abstract: A soft start circuit for a forward/reverse rotation fan includes a forward/reverse switch unit, a soft start activation unit, a soft start control unit, a Hall IC and a driver IC, wherein the soft start activation unit comprises a first signal transmission loop and a second signal transmission loop. The soft start circuit activates the soft start control unit via a first instantaneous signal outputted by the first signal transmission loop or a second instantaneous signal outputted by the second signal transmission loop to make the soft start control unit output a control signal to a speed control terminal. When the rotating direction of fan is switched from one direction into another, the fan starts rotation in a soft start mode owing to high level of the control signal transmitted from the soft start control unit to the speed control terminal during initial rotation of the fan.

Abstract: A compact field programmable gate array (FPGA)-based digital motor controller (102), a method, and a design structure are provided. The compact FPGA-based digital motor controller (102) includes a sensor interface (206) configured to receive sensor data from one or more sensors (104) and generate conditioned sensor data. The one or more sensors (104) provide position information for a DC brushless motor (108). The compact FPGA-based digital motor controller (102) also includes a commutation control (210) configured to create switching commands to control commutation for the DC brushless motor (108). The commutation control (210) generates commutation pulses from the conditioned sensor data of the sensor interface (206). The compact FPGA-based digital motor controller (102) also includes a time inverter (208) configured to receive the commutation pulses.