803results about "Controllers with pulse-train output signal" patented technology

Amperage control of a power tool motor is provided by pulse width modulation of current from a power supply. The pulse width modulation may be varied according to the determined motor current and measured power supply voltage. The power supply preferably includes a battery, such a lithium ion or nickel cadmium.

A motor control device selectively turns on or off a drive transistor in-accordance with a PWM control signal Sp, such that a drive current Im supplied to a motor is adjusted. The device also samples and holds a motor current Sm for obtaining a motor current value Ih. With reference to the motor current value Ih, the device protects the motor from an overcurrent. Sampling and holding of the motor current Sm is performed for a sampling and holding time Ts. The sampling and holding time Ts corresponds to a time period between a first point in time when the level of the PWM control signal Sp is switched for turning off the drive transistor and a second point in time that precedes the first point in time by a predetermined period. As a result, the motor current value Ih is detected with high accuracy.

A method for controlling an electric motor. A desired speed is identified for the electric motor during operation of the electric motor. A voltage is identified to cause the electric motor to turn at the desired speed. The voltage is applied to the electric motor and actively controlled during operation of the electric motor.

A drilling device prevents recurrence of an overload condition after occurrence of the overload condition, thereby improving operability and safety in the drilling device. A motor for rotating a drill is connected to an AC power source through a motor control unit, a current detector, and a power switch. A magnet is also connected to the AC power source through the power switch and a full-wave rectifier. The motor control unit rotationally drives the motor on the basis of a signal sent from a main control unit according to a state in which a motor start switch is on. The main control unit controls the motor control unit to gradually reduce a supply voltage to the motor when the motor becomes overloaded, to gradually increase the voltage to the normal power supply condition when the overload condition is vanished, and to stop power supply to the motor if the overload condition continues for a predetermined period.

Methods and apparatus for controlling a polyphase motor in implantable medical device applications are provided. In one embodiment, the polyphase motor is a brushless DC motor. The back emf of a selected phase of the motor is sampled while a drive voltage of the selected phase is substantially zero. Various embodiments utilize sinusoidal or trapezoidal drive voltages. The sampled back emf provides an error signal indicative of the positional error of the rotor. In one embodiment, the sampled back emf is normalized with respect to a commanded angular velocity of the rotor to provide an error signal proportional only to the positional error of the motor rotor. The error signal is provided as feedback to control a frequency of the drive voltage. A speed control generates a speed control signal corresponding to a difference between a commanded angular velocity and an angular velocity inferred from the frequency of the drive voltage. The speed control signal is provided as feedback to control an amplitude of the drive voltage. In one embodiment, an apparatus includes a brushless DC motor and a commutation control. The commutation control provides a commutation control signal for a selected phase of the motor in accordance with a sampled back electromotive force (emf) of that phase. The back emf of the phase is sampled only while the corresponding drive voltage for the selected phase is substantially zero, wherein a frequency of a drive voltage of the motor is varied in accordance with the commutation control signal.

A disk drive is disclosed comprising a spindle motor for rotating a disk, wherein the current applied to the spindle motor is controlled by adjusting a duty cycle of a pulse width modulated (PWM) signal. A current sensor generates a current sense signal representing a current flowing from a supply voltage. The current sense signal is integrated to generate an integration signal. The integration signal is compared to a threshold, and the result of the comparison is used to adjust the duty cycle of the PWM signal. In this manner the disk drive draws essentially constant average input current from the supply voltage which decreases the spin up time of the disk.

A disk drive is disclosed comprising a spindle motor comprising a plurality of windings for rotating a disk. The spindle motor is rotated by commutating the windings over a plurality of commutation states, wherein audible noise generated by the disk drive is reduced by phase modulating the commutation interval. Further audible noise reduction is achieved by modulating a current applied to the windings which substantially reduces discontinuities in the torque output of the spindle motor caused by phase modulation of the commutation intervals.

The speed of a fan motor is controlled by varying a DC voltage to the fan motor. A series pass transistor is used to vary the DC voltage to the fan motor. A power management controller sets the fan motor speed by outputting pulses to a pulse-to-DC voltage converter that changes the pulses to a proportional DC control voltage for controlling the series pass transistor. A tachometer output amplifier circuit is used to remove DC components and amplify to useful logic levels a low level tachometer output signal from the fan motor. The amplified tachometer signal is used by the power management controller in controlling the rotational speed of the fan motor.

A power tool such as an electric drill typically contains a gear train that couples the output spindle of the motor to the tool bit-receiving chuck. The control circuit for the power tool is operable in a ratcheting or pulse mode that causes the output spindle to rotate in discrete incremental amounts. Corresponding methods for controlling the operation of the electric motor of a power tool are also disclosed.

Apparatus are provided for motor control systems and related medical devices. In one embodiment, a control system includes a motor having a rotor, a sensor to obtain a measured displacement that is influenced by rotation of the rotor, and a control module coupled to the sensor. The control module adjusts a duty cycle for a modulated voltage applied to the motor in response to a difference between an expected displacement and the measured displacement. The expected displacement is influenced by or otherwise corresponds to a commanded rotation of the rotor.

Apparatus are provided for motor control systems and related medical devices. In one embodiment, a control system includes a motor having a rotor, a modulation module coupled to the motor, and a control module coupled to the motor and the modulation module. The modulation module generates a modulated voltage that is applied to the motor, and the control module adjusts a duty cycle of the modulated voltage to achieve a commanded rotation of the rotor and detects a degradation condition based on the duty cycle.

A door position control including an electric door actuator having a motor and a motor controller in communication with a system controller. A motor actuation operation is selected from a plurality of predetermined motor actuation operations to provide control signals to the motor controller for controlling actuation of the motor for control of door movement. Control of door movement is effected with reference to parameters specific to an installation location including an angular sweep of the door between open and closed positions and with reference to an available bus voltage for supplying power to the motor.

A method and apparatus for a pump and a pump control system. The apparatus includes pistons integrally formed in a diaphragm and coupled to the diaphragm by convolutes. The convolutes have a bottom surface angled with respect to a top surface of the pistons. The apparatus also includes an outlet port positioned tangentially with respect to the perimeter of an outlet chamber. The apparatus further includes a non-mechanical pressure sensor and a temperature sensor coupled to a pump control system. For the method of the invention, the microcontroller provides a pulse-width modulation control signal to an output power stage in order to selectively control the power provided to the pump. The control signal is based on the pressure within the pump, the current being provided to the pump, the voltage level of the battery, and the temperature of the pump.

A vehicle includes a motor for driving wheels WH, an inverter to drive the motor, and a control device to perform PWM control of the inverter. The control device performs synchronous PWM control in a case where an electric current supplied to the motor by the inverter or torque generated in the motor is larger than a threshold value; and performs the synchronous PWM control or non-synchronous PWM control in a case where the electric current or the torque is smaller than the threshold value and sets carrier frequency or a pulse number of the PWM control to be higher than the case where the electric current or the torque is larger than the threshold value. Thereby, it is possible to provide a vehicle of achieving reduction of noise, reduction of cost and improvement of fuel consumption in a balanced manner.

A rotary speed limiting device for an electric motor has a current detecting device for detecting a motor current of the electric motor, a nominal value setting for adjusting a torque, a control and / or regulating device which limits the motor current to a maximum value depending on the nominal value setting, a rotary speed detecting device for detecting a rotary speed of the electric motor, the control and / or regulating device determining a maximum value of the motor current depending on the rotary speed determined by the rotary speed detecting device.

A bidirectional buck-boost power converter 13 including a pair of inverter modules 14, 15 disposed at an output of a machine, and an inductor Lo connected between the pair of inverter modules 14, 15. A method for controlling a voltage output of a machine starter generator having an inverter rectifier and bidirectional buck-boost converter, includes outputting a dc voltage controlled by bidirectional buck-boost pulse width modulation (PWM) switching control, when the starter generator is in a generator mode.

In one embodiment, a method of and apparatus for determining calibration options in a motion control system is provided. The method includes the steps of measuring error in a commanded motion, modeling the error, identifying sources of the error; and predicting a degree to which applying compensation for one of the sources of the error might affect the error.

An interface apparatus for fan monitoring and control includes a current source amplifier that generates a programmable current in response to its input voltages. Associated with an output capacitor, which is able to reduce noise, the programmable current drives the fan at a desired speed. The rotating fan induces a ripple signal in the output capacitor, which is fed to a band-pass amplifier to produce a tachometer pulse. Through a buffer amplifier, an input control signal combined with a thermal sensor signal has direct control over the current source amplifier. Alternatively, a PWM circuit having a comparator, a ramp oscillator and the output of the buffer amplifier drives the current source amplifier in switching mode. Since the ramp oscillator can be synchronized by the input, both analog and pulse signals can function as the input control signals.

Apparatus are provided for motor control systems and related medical devices. In one embodiment, a control system includes a motor having a rotor, a sensor to obtain a measured displacement that is influenced by rotation of the rotor, and a control module coupled to the sensor. The control module adjusts a duty cycle for a modulated voltage applied to the motor in response to a difference between an expected displacement and the measured displacement. The expected displacement is influenced by or otherwise corresponds to a commanded rotation of the rotor.

A low-cost minimal-loss zero-maintenance flywheel battery, to store electric power from a DC power source by conversion to kinetic energy, and regenerate electric power as needed. Its vertical spin-axis rotor assembly is supported axially by repelling annular permanent magnets, and is centered by ceramic ball bearings which have axial preload that prevents vibration and augments axial rotor support. A regenerative multi-pole permanent-magnet motor, controlled by its 2-phase stator current, and connected by power and signal conductors to power interface electronics, is integrated within the flywheel assembly, in a vacuum enclosure supported by a self-leveling structure. Sinusoidal 2-phase stator currents are controlled by high-frequency pulse-width-modulated H-bridge power electronics that draw and regenerate controlled DC current with minimal ripple, responsive to respective 2-phase rotation angle sensors, the DC power voltage, and other settings. The electronics includes logic and over-voltage protection to prevent otherwise possible damaging current and voltage.

In the gaming machine, when the motor drive instruction to drive the motor occurs based on an instruction from an external, a constant voltage is applied to the motor and the motor is driven through the motor drive circuit 39. And when the excitation current value flowing in the motor becomes the first current value based on the constant voltage applied to the motor through the motor drive circuit 39, the voltage with on-time and off time is repeatedly applied to the motor through the motor drive circuit 39. Further, when the rotation speed of the motor becomes constant based on the voltage with on-time and off-time applied through the motor drive circuit 39, the constant voltage is applied to the motor based on the motor stop instruction through the motor drive circuit 39, thereby the motor is stopped.

Apparatus are provided for motor control systems and related medical devices. In one embodiment, a control system includes a motor having a rotor, a sensor to obtain a measured displacement that is influenced by rotation of the rotor, and a control module coupled to the sensor. The control module adjusts a duty cycle for a modulated voltage applied to the motor in response to a difference between an expected displacement and the measured displacement. The expected displacement is influenced by or otherwise corresponds to a commanded rotation of the rotor.

A method for measuring current in each phase of a three-phase inverter driven motor is based on the three-phase inverter being controlled in a PWM mode by three PWM signals including the use of a common DC-link current sensing resistor. The current on the sensing resistor is intermittently sampled. The method includes determining a modulation index for the voltage demand set by a motor controller. Based on specific mutual duty cycle conditions of the three PWM phase driving signals, sampling windows of sufficient duration are created for allowing distinct sampling of two of the phase currents.

A motor control system which can realize current detection with high accuracy by using an amplifier having an ordinary level of accuracy and can avoid deterioration of current detection accuracy even when emperature is changed. The motor control system comprises a switch circuit for supplying a driving current to a motor, a resistor for detecting the driving current, an amplification circuit for amplifying a potential difference across the resistor, an input section switch unit disposed in an input section of the amplification circuit and changing over the potential difference to be forward biased or reverse biased, an output section switch unit disposed in an output section of the amplification circuit and changing over an output voltage of the amplification circuit to be forward biased or reverse biased, and a CPU for averaging a voltage produced when the output voltage of the amplification circuit is forward biased, and a voltage produced when the output voltage of the amplification circuit is reverse biased.

A power transmission method used in a high-power wireless induction power supply system consisting of a power-supplying module and a power-receiving module is disclosed. The power-supplying module regulates its output energy by means of frequency modulation and driving power adjustment, enabling the energy to be received by the power-receiving module and transmitted through a power-receiving coil array and a primary resonant capacitor and a secondary resonant capacitor of power-receiving resonance circuit, a synchronizing rectifier, a low-power voltage stabilizer, a high-frequency filter capacitor, a first power switch, a low-frequency filter capacitor and a second power switch of a filter circuit for output to an external apparatus.

Methods and systems for controlling a power inverter in an electric drive system of an automobile are provided. A signal controlling the power inverter is modified utilizing a first voltage distortion compensation method if a modulation index of the signal is less than a first modulation index value. The signal is modified utilizing a second voltage distortion compensation method if the modulation index is at least equal to the first modulation index value.

It is an object of the present invention to prevent recurrence of an overload condition after occurrence of the overload condition, thereby improving operability and safety in a drilling device. A motor 12 for rotating a drill is connected to an AC power source 10 through a motor control unit 28, a current detector 30, and a power switch 36. A magnet 16 is also connected to the AC power source 10 through the power switch 36 and a full-wave rectifier 18. The motor control unit 28 rotationally drives the motor on the basis of a signal sent from a main control unit according to a state in which a motor start switch 38 is on. The main control unit 14 controls the motor control unit 28 to gradually reduce a supply voltage to the motor 12 when the motor 12 becomes overloaded, to gradually increase the voltage to the normal power supply condition when the overload condition is vanished, and to stop power supply to the motor 12 if the overload condition continues for a predetermined period.