6410results about "DC motor speed/torque control" patented technology

A method and apparatus for braking a motor has a braking power switching device coupled across windings of the motor. To brake the motor, the braking power switching device is cycled on and off.

The torque of a motor operated by an inverter circuit is controlled to allow maximum torque in the motor when the motor is stalled or at low rotation speeds. Control is accomplished by providing a switching frequency to the motor at a first switching frequency, detecting a rotation speed of the motor, and switching the current to the motor to a second switching frequency when the rotation speed of the motor drops to a predetermined slow rotation speed. The second switching frequency is less than the first switching frequency.

A system and method for powered surgical handpiece capable of powering various micro-cutting instruments is described. The system is comprised of a controller adapted for controlling / interfacing with a powered surgical handpiece based upon user-defined procedural information. A data entry device is used for entering the user-defined procedural information used by the controller for configuring and operating the motor control system.

Disclosed herein is a linear motor in which a plurality of coil groups are connected in series or in parallel and driving power is applied to part or all of the coil groups according to load applied to the linear motor, thereby achieving improved motor efficiency with a reduced motor size. The linear motor includes a bobbin, the plurality of coil groups wound on the bobbin, the plurality of coil groups being connected in series or in parallel to allow the driving power to be applied to part or all of the coil groups, and a magnet adapted to be linearly reciprocated by a magnetic field produced by the coil groups depending on load current flowing through the coil groups. As a result of connecting the plurality of coil groups, which are formed of a plurality of coil conductors, in series or in parallel, the capacity of the coil groups is variable depending on the load of the motor, resulting in improved motor efficiency. Also, using the coil conductors having a small cross sectional area enables reduction in the size of the 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.

To improve a surgical machine with a sensorless electric motor comprising a rotor and at least two motor windings, and with a motor controller for controlling and / or regulating the electric motor, so that the electric motor is operable with optimum efficiency at low rotational speeds and a starting of the motor in accordance with the purpose, also under load, is enabled, it is proposed that a space vector pulse width modulation (SVPWM) method for controlling and / or regulating the electric motor, in which all motor windings are able to be simultaneously supplied with electric current, be performable with the motor controller. A method for controlling and / or regulating a surgical machine is also proposed.

A motor control apparatus includes a steering column having inserted therein a steering shaft to which steering torque is transmitted, a reduction gear box coupled to the steering shaft, and an electric motor that transmits a steering assisting force to the steering shaft via a reduction mechanism in the reduction gear box. The electric motor and its control unit including a control board mounted with a control circuit, are provided side by side in the reduction gear box. A connection terminal of the electric motor is electrically connected to the control unit directly. This minimizes a connection distance between the control unit and the electric motor.

In various embodiments, a surgical stapling instrument can comprise a plurality of magnetic elements configured to articulate an end effector of the surgical instrument. The surgical instrument can comprise at least one electromagnet which can be selectively activated, or polarized, to generate a magnetic field sufficient to motivate a second magnetic element, such as a permanent magnet and / or an iron core, for example, mounted to the end effector. In certain embodiments, a surgical stapling instrument can comprise a plurality of magnetic elements configured to open and / or close an end effector of the surgical instrument. In at least one embodiment, a surgical stapling instrument can comprise a plurality of magnetic elements configured to advance and / or retract a firing bar, cutting member, and / or staple sled within the surgical instrument in order to incise and / or staple tissue positioned within an end effector of the surgical instrument.

A control system for automatically detecting moisture on the windshield of a vehicle. The automatic moisture detecting system includes an optical system for imaging a portion of the windshield on to an image array sensor, such as a CMOS active pixel sensor. The voltages of each of the pixels which represents the illumination level is converted to a corresponding gray scale value by an analog digital converter. The gray scale values corresponding to the image are stored in memory. The spatial frequency composition of the gray scale values are analyzed to determine the amount of rain present. In order to provide a control signal to control the operation of the windshield wipers of the vehicle as a function of the amount of moisture present. The system is also adapted to detect the level of fog both on the interior of the windshield as well as the exterior of the windshield. By providing a system for automatically detecting the presence of fog on the interior and exterior of the windshield, serious performance limitations of known automatic rain sensors are eliminated.

The system periodically measures the battery voltage of the toothbrush and the current in a stator portion of the motor for the appliance. The amplitude of movement of the toothbrush workpiece is determined from the measured stator current. A circuit / control program changes the duty cycle or pulse width of the drive signal from the motor if the battery voltage drops below a first threshold value and a circuit or control program changes the drive frequency of the appliance if the amplitude of the workpiece movement falls below a first threshold value. A circuit / control program terminates the operation of the toothbrush if the voltage drops below a second threshold value or if the amplitude drops below a second threshold value, both of which are less than the respective first thresholds.

An electrical hand tool machine (1) having a motor switch (2) configured as a button and a current regulator (4) disposed in the current circuit of an electrical motor (3), having a soft-start input (5), in whose branch current a timing capacitor (6) is arranged. A current-direction-dependent element (7) is arranged between the soft-start input (5) and the capacitor (6).

A control console to remotely control medical equipment is disclosed having a base with an ergonomically adjustable pedal system. The base further has an opening to receive the pedal system. The pedal system includes a moveable pedal tray with a pedal base. The tray includes a first left pedal assembly and a first right pedal assembly, and an upper tier having a second left pedal assembly and a second right pedal assembly respectively in alignment with and elevated above the first left pedal assembly and the first right pedal assembly. Rollers are rotatable coupled to the moveable pedal tray to allow it roll over a floor. A drive assembly is coupled between the moveable pedal tray and the base. The drive assembly applies a force to the to roll the moveable pedal tray over the floor within the opening of the base.

A system for automatic regulation of daylight admitted by a window in the presence of artificial illumination produced by a high-efficiency (e.g., fluorescent-type) electric lamp. A preferred embodiment, adaptive window covering system 10, consists of an illuminance sensor 11, a conventional control apparatus 12, and a conventional shading means 13. System 10 is used in conjunction with a conventional, high-efficiency, electric lamp 14 and a conventional window 18, in a room 19. Sensor 11 produces a signal dependent on power contained in a portion of the daylight spectrum, but substantially insensitive to power contained in the spectrum of artificial illumination produced by lamp 14. In a preferred embodiment, sensor 11 includes a silicon photodiode and optical low-pass filter to provide a spectral response which extends from approximately 800 to 1200 nanometers, which falls outside the spectrum produced by typical fluorescent lamps (e.g, 300 to 750 nanometers). Sensor 11 is oriented to sample the ambient illumination in room 19, which includes both daylight and artificial components. Control apparatus 12 produces an actuating signal dependent on the output of sensor 11. Shading means 13 varies the amount of daylight admitted by window 18 as a function of the actuating signal produced by control apparatus 12. Thus, system 10 varies the amount of daylight admitted by window 18 as a function of the power contained in a portion of the daylight spectrum, but independent of the power contained in the spectrum produced by lamp 14.

The present invention relates to synchronized vibration devices that can provide haptic feedback to a user. A wide variety of actuator types may be employed to provide synchronized vibration, including linear actuators, rotary actuators, rotating eccentric mass actuators, and rocking mass actuators. A controller may send signals to one or more driver circuits for directing operation of the actuators. The controller may provide direction and amplitude control, vibration control, and frequency control to direct the haptic experience. Parameters such as frequency, phase, amplitude, duration, and direction can be programmed or input as different patterns suitable for use in gaming, virtual reality and real-world situations.

The disclosure relates to General Synchronized Vibration devices that provide haptic feedback to a user and improve the performance of existing vibratory devices. Different actuator types may be employed to provide synchronized vibration, including linear rotary actuators, rotating eccentric mass actuators including interleaved rotating mass actuators, and rocking mass actuators. A controller sends signals to one or more driver circuits to provide adjustment of vibration magnitude, frequency, and direction of the actuators. The system may apply forces onto an object, and a sensor measures a feature(s) of the object. This information is provided to a vibration device controller, which can then modify the vibration waveform to improve overall system performance. Fourier synthesis can be used to approximate arbitrarily shaped waveforms by controlling the phase and frequency of vibration actuators. These waveforms can include asymmetry where the peak force in one direction is higher than the peak force in another direction.

The invention relates to a system and a method for performing a manufacturing operation at a predetermined position relative to a first path. The system includes a plurality of first elements mounted for movement relative to the first path. The first elements have a plurality of motion parameters which are independently controllable. Active elements are operatively associated with reactive elements to produce relative movement between the first elements and the first path, with the active elements controlling the relative movement. A controller controls the activation of the active elements and a first tool is associated with each first element for performing at least part of the manufacturing operation. The system may also include at least one second element and a second path. The method includes the steps of mounting a plurality of first carriages for movement relative to a first path, operatively associating a plurality of active elements with at least one reactive element to produce relative movement between the first carriages and the path, associating a first tool with each first carriage for performing at least part of the manufacturing process, and controlling the activation of the active elements.

An electric rotary machine is disclosed which can adjust relative angles of sub-rotors continuously and regardless of torque direction without generating an attractive force between the field magnets of the sub-rotors. The electric rotary machine includes: a stator having a winding; a dual rotor which is rotatably disposed with a gap from the stator and divided axially along a shaft into a first rotor and a second rotor each having field magnets with different polarities arranged alternately in a rotation direction; a mechanism for varying the axial position of the second rotor relative to the first rotor continuously; and a non-magnetic member located between the first rotor and the second rotor.

A detection system for detecting a dangerous condition for an operator using a power tool of the type which has an exposed blade relative to a work surface and a protection system for minimizing, if not eliminating the possibility of a user being injured by contacting the blade. In one preferred embodiment of the present invention, a proximity detection system is capable of detecting the presence of a user near the blade of a table saw and a protection system that can either retract the blade below the work surface of the table saw or terminate the drive torque to the blade which can result in rapid stopping of the saw blade by a work piece that is being cut.

In a left ventricular assist device (LVAD) a rotodynamic blood pump (10) is powered by a brushless DC motor (12). A power supply (14) supplies power to the motor (12). Three feedback channels, one for each of voltage, current, and motor speed lead to a microcontroller or microprocessor (18). The three feedback waveforms are analyzed, and from these waveforms, motor input power, patient heart rate, current pump flow rate, and systemic pressure are determined. The microprocessor (18) then calculates a desired flow rate proportional to the patient heart rate. The microprocessor communicates a new power output to a commutation circuit (16), which regulates power to the motor (12). The pump (10) also includes safety checks that are prioritized over desired pump flow. These include prevention of ventricular suction, low pulsatility, minimum and maximum pump speed, minimum speed-relative pump flow, minimum absolute pump flow, minimum and maximum motor input power.

A control unit controls a vehicle having a body to allow a user to step on, a power generator arranged to generate power that drives the body, and a first sensor and a second sensor. Each sensor preferably outputs a load value representing a load that has been applied to the body. The control unit preferably includes a processor arranged to output a command value associated with a bias of the load based on first and second load values that have been respectively detected by the first and second sensors, and a drive controller arranged to control the power generator in accordance with the command value.

A motor control system for a brushless and sensorless DC motor for driving a compressor, pump or other application, includes a protection and fault detection circuit for detecting a locked rotor and a rotor which has stopped because of lost rotor phase lock. The motor control system also includes an off-the-shelf motor control integrated circuit having an input for disabling power outputs to the motor phase coils. The protection and fault detection circuit uses a back EMF sampling circuit coupled to the motor phase coils and momentarily disables power to the motor phase coils, via the motor control integrated circuit input, to determine if the motor rotor is rotating. The system also monitors supply voltage, supply current, temperature, and motor speed limits to detect faults and protect system components.

An integrated torsional mode damping method for a current source converter, including a rectifier, an inverter, and a DC link inductor coupled between the rectifier and the inverter, includes sensing a signal representative of torque on a shaft coupled to the inverter or rectifier; using the sensed signal for detecting a presence of a torsional vibration on the shaft; and damping the torsional vibration by modulating active power through the respective inverter or rectifier.