Abstract: A sensorless permanent magnet motor system that prevents negative torque caused by back EMF. The system determines the position of the rotating permanent magnet by monitoring back EMF generated on an inactive coil of the motor system. A snubber circuit is used to prevent the back EMF from causing negative torque on the motor. The voltage of back EMF used to power a logic circuit, such as a microcontroller, that controls the operation of the motor. The microcontroller controls the operation of the motor by detecting back EMF and is also partially powered by the back EMF.

Abstract: To achieve peak acoustic and power performance, the coil or applied current should be in phase or substantially aligned with the back electromotive force (back-EMF) voltage. However, there are generally phase differences between the applied current and back-EMF voltage that are induced by the impedance of the brushless DC motor (which can vary based on conditions, such as temperature and motor speed). Traditionally, compensation for these phase differences was provided manually and on an as-needed basis. Here, however, a system and method are provided that automatically perform a commutation advance by incrementally adjusting a drive signal over successive commutation cycles when the applied current and back-EMF voltage are misaligned.

Abstract: In an imaging apparatus having a toner container, a method of periodically calibrating a back EMF constant Ke used in a speed control circuit of a DC motor used for driving for a toner metering device. To adjust the value of the back EMF constant Ke, the method uses a plurality of sampled back EMF measurements together with a calculated actual speed of rotation of the toner metering device as measured using motion sensor.

Abstract: An information handling system includes a three phase brushless direct current motor and a motherboard which in turn includes a drive circuit. The three phase brushless direct current motor is configured to rotate a cooling fan in the information handling system based on a control signal. The drive circuit is connected to the three phase brushless direct current motor, and the drive circuit is configured to adjust the control signal sent to the three phase brushless direct current motor based on a back electromagnetic flux signal.

Abstract: An electrical machine having a stator and a rotor. The stator includes a core and a plurality of windings disposed on the core in a multiple-phase arrangement. The rotor is disposed adjacent to the stator to interact with the stator. A method of operating the motor includes applying a pulsed voltage differential to first and second terminals of the windings resulting in movement of the rotor; monitoring the back electromotive force (BEMF) of the windings to sense rotor movement; after the applying and monitoring steps, monitoring the BEMF of the windings to determine whether the rotor is rotating in a desired direction, and electrically commutating the motor when the rotor is rotating in the desired direction and zero or more other conditions exist.

Abstract: A brushless motor driven by a sensorless driving circuit includes a rotating body capable of being rotated about a center axis; a rotor magnet arranged coaxially with the rotating body; a stator disposed opposite the rotor magnet; and at least one coil wound around the stator. The brushless motor is driven according to a signal containing a third harmonic component relative to a fundamental wave component in an induced electromotive force. Further, an amplitude ratio of the third harmonic component to the fundamental wave component in the induced electromotive force generated in the coil preferably is about 1% or higher.

Abstract: A feed motor lock detection device detects a back-electromotive voltage in a feed motor M and checks whether the feed motor M is in a driven state or in a non-driven state based on the level of the back-electromotive voltage.

Abstract: Provided are an apparatus and method of controlling a motor by compensating for recurring false speed errors generated in a direct current (DC) motor. The apparatus includes a learning control unit adapted to calculate recurring false speed errors related to a mechanical tolerance associated with the motor in each one of a plurality of controlling sections associated with a single rotation of the motor, and generate a corresponding reference speed for each controlling section, and a motor control unit adapted to control the rotational speed of the motor in relation to a speed error defined by a difference between the reference speed for each controlling section and an actual measured speed of the motor for each controlling section.

Abstract: A circuit for controlling a voice-coil motor (VCM) may incorporate a pulse-width modulation driver to drive the VCM, a zero-current detector to determine whether the current across the VCM is zero, and a Back-EMF voltage detector to measure the voltage across the VCM when the current across the VCM is determined to be zero. The circuit may determine the current velocity of the VCM and use this information to control the velocity of the VCM.

Abstract: A method for determining the rotary speed of an electrical machine, especially of a direct current motor, which is controlled in PWM operation, the tracking voltage of the electrical machine being measured and the rotary speed being ascertained from that. The rotary speed fluctuations are able to be substantially reduced if the electrical machine is controlled using a control signal which has a PWM phase, in which the electrical machine is periodically switched on and off using a prespecified pulse duty factor, and which has a measuring phase in which the electrical machine is switched off. The rotary speed is measured in the measuring phases, in this instance, and is calculated in the PWM phases based on a model.

Abstract: A technique for determining an alignment error of a Hall sensor location in a brushless DC motor drive, by measuring the back EMF waveform, preferably while the motor is coasting. According to the technique, an angular offset is calculated between a selected BEMF waveform and a selected Hall signal. Such offsets are preferably calculated for each phase individually. The offsets may be advantageously stored in the motor control unit and used to adjust the output motor control signals for maximum torque.

Abstract: A barrier operator comprises a first measuring apparatus for measuring a current used by a direct current (dc) motor to move a barrier and a second measuring apparatus for measuring a generated voltage of the dc motor. A controller is coupled to the first measuring apparatus and the second measuring apparatus. The controller is programmed to calculate a torque of the dc motor by using the current and to determine when an obstruction exists in the path of the barrier based upon the calculated torque.

Abstract: A vibration linear actuating device includes a vibrating linear actuator and a driver (52) for driving actuator. Actuator includes mover having permanent magnet magnetized in a radial direction, stator having coil (2) and facing the permanent magnet, and elastic body for coupling stator to mover. The driver includes driving section having switching element (Q5) for powering coil (2), output controller (27) for controlling switching element (Q5), zero-cross detector (25) for detecting a zero-cross point of back electromotive force generated in coil (2) and having an output to be fed back to the output controller (27). In this structure, the driver powers coil (2) in one way to keep mover vibrating in corporation with elastic body.

Abstract: The methods for starting a Hall-less single-phase BLDCM having an asymmetrical air gap are proposed. The provided methods are employed to input a specific amount of current impulse and stop the current impulse at a specific time such that the rotor of the single-phase BLDCM having an asymmetrical air gap can be realized to rotate in the pre-determined direction through one of the cogging torque and the rotor inertia after that specific time so as to accomplish the normal starting of a motor without the Hall-effect sensor.

Abstract: Practically ideal electrical resonance is employed to soley provide armature power, and stator power if desired, to run DC motors. A practically ideal parallel resonant tank circuit (PIPRC) is used wherein the quotient of the “tank current” divided by the “line current” (called the “quality” or “Q” of the tank) is (1) greater than one, (2) large enough to allow the percent efficiency of the electric motor to be equal to or greater than 95%, and (3) removes enough back emf or enough of the influence thereof so that criteria (1) and (2) can be realized throughout the entire operating range of the motor. Only one PIPRC is needed for a DC motor. Recontrolling and/or redesigning is done for two reasons.

Abstract: Techniques sense a back-emf voltage from a brushed permanent magnet motor. Such techniques can be used for a variety of purposes, such as to estimate the current that is being applied to the motor, to estimate the motor's velocity, position, torque, and the like. One aspect of the invention includes the deactivation of power applied to the motor, and the monitoring of the back-emf of the voltage while power is not applied.

Abstract: A low noise electronic three phase bridge controlled brushless DC motor suitable for whiteware appliance pumps and other appliance applications. Back EMF zero crossing sensing is used to determine rotor position and thus stator winding commutation times. Motor torque and speed are controlled by pulse width modulating the operation of that bridge switching device which has just been switched from an OFF state to an ON state on each new commutation. All three stator windings have current flowing in each winding commutation to improve motor current waveform and thereby reduce motor noise, but the current in one winding is always terminated before the end of the commutation period to allow the back EMF in that winding to be sensed to zero crossing.

Abstract: A system and a method for starting a brushless DC motor are provided. The method includes applying commutation pulses to at least two phase coils to induce a rotor to rotate to a starting position and then de-energizing the at least two phase coils. The method further includes applying commutation pulses to at least two phase coils to induce the rotor to rotate from the starting position in a predetermined direction. The method further includes de-energizing all phase coils for a first time interval after the rotor is rotating and sampling a back EMF signal in at least one of the phase coils to determine a first value indicative of an electrical period of the back EMF signal or a portion of an electrical period of the back EMF signal. Finally, the method includes applying commutation pulses to at least two phase coils for a second time interval, the second time interval being based on the first value.

Abstract: The present invention is a driving circuit for a DC brushless fan motor, comprising a control unit, a motor, a Hall element, a signal output unit, a temperature control circuit, a reverse protection circuit and a counter-electromotive force (CEMF) removal circuit, as tied in with a plurality of resistors, capacitors, diodes and transistors. Accordingly, the ambient temperature is sensed by the temperature control circuit and is fed back to control the rotation rate of the motor.

Abstract: A digitally adaptive controller circuit for commutating a brushless, sensorless, DC motor in either of two directions adapted to receive digital back electromotive force (BEMF) detector signals. The digital circuit is driven by an input clock that is adjustable to configure the motor controller for use with a broad range of DC motors. The circuit includes commutational logic that decodes a current commutational state and a user-definable binary direction input into logic levels for digital control signals for controlling motor drive switches. The circuit also includes a signature analyzer to compare logic levels in the BEMF detector signals with expected logic levels based on an expected rotor position and direction of rotation. The digital circuit commutates the motor if the logic levels in the BEMF detector signals are at the expected logic levels. The digital circuit is compact and simple enough to be deployed onto a single programmable logic device.

Abstract: A process to start a brushless direct current motor with a multiphase stator winding is disclosed, in which, during rotor standstill, a plurality of current impulses is intruded on the stator winding, the current rise time until a current threshold is reached is measured in the stator winding with every current impulse and the rotor position is derived from the measured current rise times. A more precise determination of rotor position is achieved with lower control-related effort for a regulated sensorless start-up in that a plurality of test current impulses is successively intruded on the stator winding in such a way that the test current impulses generate stator flow vectors offset by the same angular increments over 360° electrically in the stator. The current rise time for each stator flow vector is measured in the total current of the stator winding and the phase position of the stator flow vector with the smallest current rise time is determined as the rotor position.

Abstract: Method for providing current regulation and a current controller (10) for an electric machine (30) are provided. The method includes receiving a state vector time signal (36) indicative of a time interval when a switching state vector is activated and comparing the received state vector time signal to a commanded state vector time signal (38). The method further includes using the result of the comparison to regulate a direct axis current signal (42, 44) input to an electric machine controller. The current controller (10) includes a state vector error comparator for comparing a received state vector time signal to a commanded state vector time signal and generating a state vector time error. This error is processed by a PI controller, coupled to the state vector error comparator, for providing a direct axis current signal output responsive to the state vector time error to an electric machine.

Abstract: Methods and apparatus permit: monitoring a level of a power source that provides operating power to a control circuit, the control circuit being of a type that senses signals in windings of a polyphase motor to maintain synchronization therewith; and converting kinetic energy of the polyphase motor into operating power for the control circuit when the level has fallen below a threshold level, such that the control circuit is capable of maintaining synchronization with the polyphase motor.

Abstract: A method of reducing torque ripple and noise for an brushless DC machine comprising: determining a control frequency for the electric machine, the control frequency indicative of an existing current command to and a rotational velocity of the electric machine; multiplying the control frequency by a selected multiple and forming a modulating signal responsive thereto; and formulating a modified command profile. The method also includes: correlating and synchronizing the modified command profile with the existing current command and a rotor position for the electric machine; and generating a modulated current command to the electric machine.

Abstract: A device for position determination in a sensorless direct current motor has a plurality of inductivities arranged in corresponding phases and inducing alternating voltages in a motor windings, a plurality of resistances located in phase branches to be evaluated for a position determination of a rotor position of the sensorless direct current motor, and a plurality of comparator components each associated with the corresponding phase branch to be evaluated.

Abstract: A method and system for determining the commutation position in a DC machine using a single-bit rotor sensor and the back EMF signal from a stator winding by calculating a delay value, which is equal to the time elapsed between detection of the position signal and the back EMF signal, and establishing commutation after a period of time equal to the delay value has elapsed from when the position signal is detected.

Abstract: Methods and circuits detect operational information about DC fans powered by pulse width modulation, such as detecting fan presence in a device and/or detecting rotational speed. Output pulses produced by the fan related to the rotational speed are utilized to produce temporary reductions of voltage at the input of a control circuit. The control circuit may count the temporary reductions per unit of time to detect the speed. A pull down resistor may be coupled to the input to pull the input to a continuously low voltage when the DC fan is not present to otherwise provide a pull up at the input, and the control circuit may detect a missing fan from the continuously low voltage. Additionally, or alternatively, a secondary voltage may be provided to the DC fan in addition to the pulse width modulation while a consistently high voltage is provided to the input of the control circuit.

Abstract: A local oscillator and logic circuit pulses the open winding of a brushless DC motor at start up and the back EMF is used to generate a voltage to boost the voltage available to the control circuit for optimizing performance when starting with low supply voltage. As the rotor of a motor rotates and the windings are commutated by the drive electronics there is generated in each winding a voltage caused by the collapse of the current and the inherent inductance of the winding. These voltages exceed the normal operating voltage of the motor. The energy in these voltages is used to generate a regulated power feed to the analogue circuitry of the control circuit at a suitable voltage level. During steady state conditions, when the motor is running, the commutation of the windings is continual and there is ample energy available to power analogue electronics, and, if required, associated digital electronics as well.

Abstract: A device for controlling a motor intended to set an arm provided with a head for reading/writing information in motion with respect to a surface carrying information. The device having a controller for enabling the power supply of the winding of the motor to be managed and a measurer for measuring the value of a counter-electromotive force induced in the winding by the movement of the rotor when the power supply of the winding is interrupted. This device enables the angular speed of the arm to be measured and controlled during an emergency return phase of the arm towards a rest position.

Abstract: Practically ideal electrical resonance is employed to soley provide armature power, and stator power if desired, to run DC motors. A practically ideal parallel resonant tank circuit (PIPRC) is used wherein the quotient of the “tank current” divided by the “line current” (called the “quality” or “Q” of the tank) is (1) greater than one, (2) large enough to allow the percent efficiency of the electric motor to be equal to or greater than 95%, and (3) removes enough back emf or enough of the influence thereof so that criteria (1) and (2) can be realized throughout the entire operating range of the motor. Only one PIPRC is needed for a DC motor. Recontrolling and/or redesigning is done for two reasons.

Abstract: The present invention provides a method for shifting the instant of commutation for a sensorless and brushless direct-current motor (1), whose stator windings are fed by a multi-phase converter connection. The converter connection includes an output stage control (2), a commutation logic (3), a phase selector (4), and phase discriminator (5). A commutation detection (6) is supplied at one input (46) with the instantaneous value of the voltage induced in a phase, the instantaneous value being determined by the phase selector, and at a second input (47), with a reference voltage (Uref) for comparison. The reference voltage (Uref) can be changed by a commutation shift (7) in correspondence with a specific characteristic curve (71). A manipulated variable (Ust) is supplied by a manipulated-variable calculation (8) to the commutation shift (7) as a function of the setpoint speed (Nsetpoint) of the motor. The commutation shift takes place in an advantageous manner in a parabola shape.

Abstract: An electric system utilizes dynamic impedance changes in windings of an electric motor to measure/monitor mechanical position. The method employs a bridge amplifier to measure voltage at a center node or windings against a voltage derived from a reference network. When a winding of the motor is driven, the winding forms a voltage divider across the center node. Impedance changes in windings occur as rotor poles pass by stator poles. The center node voltage varies with these impedance changes in legs on either side; this variation with respect to the reference network corresponds to measurement of rotational position. These measurements provide position/velocity feedback to a servo controller as long as current runs through a winding. This position sensing also applies to controlling commutation for brushless DC motor. Impedance measurement use normal motor-drive current for excitation without additional sensing signals, extra “sense” windings, or external sensors.

Abstract: A digitally adaptive controller circuit for commutating a brushless, sensorless, DC motor in either of two directions adapted to receive digital back electromotive force (BEMF) detector signals. The digital circuit is driven by an input clock that is adjustable to configure the motor controller for use with a broad range of DC motors. The circuit includes commutational logic that decodes a current commutational state and a user-definable binary direction input into logic levels for digital control signals for controlling motor drive switches. The circuit also includes a signature analyzer to compare logic levels in the BEMF detector signals with expected logic levels based on an expected rotor position and direction of rotation. The digital circuit commutates the motor if the logic levels in the BEMF detector signals are at the expected logic levels. The digital circuit is compact and simple enough to be deployed onto a single programmable logic device.

Abstract: Method and apparatus for initializing a disc drive to bring a spindle motor to a final, operational velocity after a disc drive processor reset condition. The spindle motor is rotated using electronic commutation and back electromotive force (bemf) detection. Upon initialization of the disc drive, a control circuit checks for the presence or absence of detected bemf. The absence of bemf indicates the spindle motor is either at rest or is rotating at a relatively low velocity. In the absence of bemf, the electrical rotational position of the spindle motor is determined, a short braking pulse is applied to the motor, and rotation of the spindle motor is detected in relation to changes in the electrical rotational position. Further breaking pulses are applied until no apparent change in electrical rotational position is detected, after which the spindle motor is accelerated from rest to the final, operational velocity.

Abstract: A system and method of advancing the commutation sequence of a brushless DC motor is provided. The motor having a plurality of coils, each of the coils coupled together at one end to a common center tap and coupled at an opposite end, through a respective coil tap, to both a source voltage and ground via selectively actuateable switches having diodes coupled in parallel therewith. The motor operates in a pulse width modulation (PWM) mode having PWM-on states and PWM-off states. During PWM-off states, a coil tap voltage from the coil tap of a floating phase is provided to a preconditioning circuit. The preconditioning circuit adjusts the floating phase coil tap voltage to compensate for an amount of voltage substantially equal to an amount of voltage by which a voltage at the center tap deviates from zero. The preconditioning circuit further includes sharpening circuitry for amplifying the adjusted floating phase coil tap voltage.

Abstract: An electric motor for operating a device for wiping a window of a motor vehicle has an electric motor part, and a control device for controlling/regulating a power of the electric motor part, the control device being formed so that it is programmable with a parameter a power limiting by limiting a torque to a nominal torque.

Abstract: A motor drive circuit for driving a brushless motor having a rotor and exciting coils of respective phases. A square wave rotor position signal for each phase is produced wherein a half period of the rotor position signal corresponds to a time period from a polarity inversion of an induced voltage of the exciting coil to the next polarity inversion of the induced voltage. Based on the rotor position signal, excitation of the exciting coils is performed by controlling switching elements for conducting excitation currents by using square wave on-control and/or pulse width converted square wave pulse width modulation (PWM) control. A pulse width converted sinusoidal wave PWM signal is generated whose pulse width varies according to a sinusoidal function. Excitation of the exciting coils is controlled based on the pulse width converted sinusoidal wave PWM signal immediately before and after the square wave on-controlled portions and/or the pulse width converted square wave PWM controlled portions.

Abstract: A method and system for driving a phase of an electrical motor are disclosed. The method and system detect the back electromotive force being generated by a coil. The back electromotive force is amplified or attenuated to a level necessary to drive the motor at a desired speed and is fed back into the coil. The detected back electromotive force signal that drives the motor is proportional to, in phase with, and at the same frequency as the back electromotive force signal being generated by the coil. Using the back electromotive force to produce the drive signal permits autosynchronization of the drive signal without use of position sensors and reduces acoustic noise and velocity modulation associated with sudden torque shifts.

Abstract: A variable speed power tool may include a speed adjusting device and/or a maximum speed adjusting device for adjusting the operating speed, and a fixed operating speed switch. An operator adjustable speed adjusting device having a position maintaining mechanism also may be utilized. When manipulated by the operator, the fixed operating speed switch gives priority to the adjusted position of the speed adjusting device and adjusts the operating speed to a preset operating speed. In the alternative, a switching device and an internal integrated circuit may be utilized to adjust the operating speed to a target speed using feedback control. The switching device preferably selects a voltage corresponding to the target speed from either a voltage representative of the position of the speed adjusting device or a predetermined voltage representative of the present operating speed.

Abstract: An error such as disconnection or short on the current path from said dc power supply to a switching element via the dc motor is detected by judging whether variation in a voltage at a junction point between the dc motor and the switching element tracks variation in the pulse width modulation signal for the switching element. If this is false for a predetermined interval, this apparatus judges there is the error. The error is judged by variation in a voltage at a junction point between the dc motor and the switching element tracks variation in the pulse width modulation signal, so that though the dc motor is driven by a fan for cooling the engine of a motor vehicle because of wind due to traveling of a motor vehicle, the error can be judged accurately.

Abstract: A motor control circuit wherein Bemf zero crossings are sensed to provide phasing information. To avoid incorrect timing (due to detection of zero crossings which may be caused by switching noise when the power transistors switch to commutate other phases), the Bemf detection is masked. Advantageously, the Bemf detection is masked not only for the normal masking period (including an additional percentage beyond the minimum period), but is also for an additional period, if the Bemf output is not of the expected polarity.

Abstract: The present invention relates to the positioning of the read/write transducer heads of an hard disk (HD) in a designated landing zone when requested or when the electrical power is removed from the drive. In particularly it relates to the detection of the back electromotive force (BEMF) of the motor involved in the positioning of the read/write transducer heads.

Abstract: A motor controlling semiconductor integrated circuit for controlling a motor by a PLL control is provided comprising output transistors for driving a motor, a position detecting means detecting a rotational position of a rotor in said motor, for generating a position detection signal, a phase comparing means comparing said position detection signal with a reference clock, for generating a phase difference detection signal, and means receiving said phase difference detection signal, for controlling an on-duty of said output transistors on the basis of a duty of said phase difference detection signal.

Abstract: A method for detecting a zero-cross event of an induced back electromotive force (BEMF) or of a nullification instant of a periodic current in a PWM driven winding, by circuits generating an analog signal representative of the induced BEMF or of the nullification instant of the periodic current, comparing the analog signal with zero and producing a first logic signal, generating a PWM driving signal, and storing a time between two consecutive zero-cross events, is provided. The method may include storing a time between a last two zero-cross events and synchronizing the PWM driving signal from a last zero-cross event having a duration equal to a difference between an established time based upon the stored time interval and a first time. If a new zero-cross event is not detected within the established time, switching of the PWM driving signal may be disabled for a time having a maximum duration equal to a second time or until a new zero-cross event is detected.

Abstract: A circuit for providing commutation control signals to a commutator for a polyphase brushless dc motor in a mass data storage device includes an accumulator (48) to accumulate a digital count that is proportional or related to a phase difference between the commutation control signals and a motor bemf. A digital variable frequency oscillator (52) generates an oscillator output signal of frequency proportional to the digital count to reset the accumulator (68) after a predetermined time determined by the frequency. The circuit may also include a digital filter (50) between the digital accumulator (48) and the digital variable frequency oscillator (52) to generate a magnitude signal (DRC) of magnitude proportional to the accumulated count for delivery to the variable frequency oscillator (52) to control the frequency thereof.

Abstract: In a motor driving device, the currents supplied from a driver (3) to three-phase coils (2) of a motor are made to flow through a resistor (R), and the voltage appearing across this resistor (R) is fed to the positive input terminal of a current limiting circuit (8). The differential signal between this voltage and a voltage (V) fed to the negative input terminal of the current limiting circuit (8) is fed as a voltage signal to an OR circuit (9). Also an FG signal produced by a logic circuit (5) to represent the rotational speed of the motor is fed, through a speed discriminator (6) and a filter (7), as a voltage signal to the OR circuit (9). The OR circuit (9) feeds a voltage signal having a high level to a PWM comparator (11), which produces a PWM signal and feeds it to the logic circuit (5). Thus, when the currents supplied to the three-phase coils (2) are about to exceed a limit, the currents are limited so as not to exceed the limit by the voltage signal output from the current limit circuit (8).

Abstract: A method for controlling an electromagnetic actuator having an arm connected thereto uses a circuit that temporarily places in a high impedance state output nodes connected to a winding of the electromagnetic actuator. A detected BEMF is compared with a lower threshold and an upper threshold. Current in the electromagnetic actuator is monitored and controlled. A current pulse is provided to the electromagnetic actuator based upon the comparison of the detected BEMF with the lower and upper thresholds. The respective amplitudes of successively provided current pulses having a same polarity are progressively increased, and an amplitude of a provided current pulse having a polarity opposite a polarity of a preceding current pulse is decreased. The amplitude of the driving current pulses provided to the winding of the electromagnetic actuator advantageously adapts automatically to varying frictional conditions, or to any other cause of variation of the mechanical load of the actuator.

Abstract: A motor for use with a power supply comprising a stator, a rotor in magnetic coupling relation to the stator, a plurality of insulated gate bipolar transistors (IGBTs), a user interface, a microcontroller and an application specific integrated circuit (ASIC). Each IGBT has a control input port and is connected between the stator and the power supply for selectively applying power to the stator in response to a control signal applied to the control input port. The user interface provides user signals indicative of one or more desired operating parameters of the motor. The microcontroller has control inputs receiving the user signals and has low voltage output ports for providing low voltage output signals for commutating the stator as a function of the user signals. The ASIC has low voltage input ports connected to the low voltage output ports of the microcontroller and has high voltage output ports connected to the control input ports of the IGBTs.

Abstract: An apparatus for controlling an actuator in response to a target speed voltage signal, the actuator having a moveable member and having a coil that influences movement of the member. A first summing node is provided having a control output voltage, for summing or subtracting voltages applied thereto, as the case may be and receiving the target speed voltage signal at a first, summing input thereto. A proportional compensation unit is provided, receiving the control output voltage and providing as an output a proportionally compensated output signal. An integral compensation unit is provided, receiving the control output voltage and providing as an output an integrally compensated output signal. An inverse compensation unit is provided, receiving the target speed voltage signal as an input and providing an inversely compensated output signal having a voltage corresponding to the voltage of the target speed voltage signal multiplied by the inverse of a predetermined amplification factor.