4092results about "Electric motor speed/torque regulation" patented technology

A powered surgical tool with a housing that contains a power generating unit such as a motor. A control module is disposed in a shell that is mounted in the housing. The control module contains a control circuit for regulating the actuation of the power generating unit. The power generating unit emits a signal representative of the operating state of the unit that is transmitted through the structural material forming the shell. Also internal to the control module shell is a sensor that monitors the signal emitted by the power generating unit. This signal output by the sensor is applied to the control circuit. The control circuit, based on the sensor signal regulates actuation of the power generating unit. Wherein the power generating unit is a motor, the signal emitted is the magnetic field that varies with rotor position. The sensor monitors the strength of this field.

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 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.

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.

A permanent magnet DC brushless motor control assembly permits a user to select the permanent magnet DC brushless motor operating characteristics by selecting appropriate control circuits to interface with the motor. The assembly includes a permanent magnet DC brushless motor, a commutator electrically coupled to the motor, and at least one control module electrically coupled to the commutator, to control operating characteristics of the permanent magnet DC brushless motor.

A motor controller includes a power source unit providing a direct current output, a drive unit including a drive coil, first and second transistor units, a voltage drop component, and a processor. The transistor units are coupled to the power source unit and the drive unit, and enable electricity to flow through the drive coil in a first direction when the first and the second transistor units are in conducting and non-conducting states respectively, and in an opposite second direction when the first and the second transistor units are in non-conducting and conducting states respectively. The voltage drop component has a first end coupled to the drive unit and a grounded second end. The processor is coupled to a junction of the drive unit and the voltage drop component, and provides first and second pulse-width-modulated signals to the first and second transistor units, respectively.

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 method and circuit for determining the speed and / or counting the revolutions of brush and commutator motors is described. The method and circuitry detects signals present on the windings of the motor due to commutation that occurs at the brushes and commutator of the motor. This method can be used to simply monitor & indicate the motor speed and revolutions or to form the basis of a motor control.

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.

A variable speed wind turbine employing a rotor connected to a multiplicity of synchronous generators with wound field or permanent magnet rotors. A passive rectifier and an inverter are used for power transfer back to the grid. A Turbine Control Unit (TCU) commands a required generator torque based on rotor speed and power output of the turbine inverters. Torque is controlled by regulating the DC current by control of the inverter. A main-shaft-damping filter is provided by measurement of the DC bus voltage. In high winds the turbine remains at a constant average output power through a constant torque command and a varying pitch command to a rotor pitch servo system. A set point is fixed at the inverter output such that output VAR load is minimized running the turbine at very nearly unity power factor. Dynamic VAR and power factor control is provided by a separate VAR apparatus.

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.

A variable speed wind turbine employing a rotor connected to a multiplicity of synchronous generators with wound field or permanent magnet rotors. A passive rectifier and an inverter are used for power transfer back to the grid. A Turbine Control Unit (TCU) commands a required generator torque based on rotor speed and power output of the turbine inverters. Torque is controlled by regulating the DC current by control of the inverter. A main-shaft-damping filter is provided by measurement of the DC bus voltage. In high winds the turbine remains at a constant average output power through a constant torque command and a varying pitch command to a rotor pitch servo system. A set point is fixed at the inverter output such that output VAR load is minimized running the turbine at very nearly unity power factor. Dynamic VAR and power factor control is provided by a separate VAR apparatus.

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.

A system may regulate voltage supplied from a power source to an integrated circuit and / or an inertial device. A minimal voltage may be maintained in the integrated circuit by temporarily cutting off current to the inertial device to supply surges of voltage to the controller. Optionally voltage may be smoothed between said surges for example by adding capacitance and / or a current restrictor.

A powered surgical tool with a housing that contains a power generating unit such as a motor. A control module is disposed in a shell that is mounted in the housing. The control module contains a control circuit for regulating the actuation of the power generating unit. The power generating unit emits a signal representative of the operating state of the unit that is transmitted through the structural material forming the shell. Also internal to the control module shell is a sensor that monitors the signal emitted by the power generating unit. This signal output by the sensor is applied to the control circuit. The control circuit, based on the sensor signal regulates actuation of the power generating unit. Wherein the power generating unit is a motor, the signal emitted is the magnetic field that varies with rotor position. The sensor monitors the strength of this field.

An electronically commutated brushless DC motor primarily for fractional horsepower applications of the type where at any instant one motor winding is unpowered and used to detect back EMF zero-crossings which information is used to initiate winding commutations. The duration of the pulse produced in this winding due to dissipation of stored energy by free-wheel diodes in parallel with the commutation devices after supply of current has been removed from this winding is used to provide a measure of motor current. This allows for simplified commutation device current limiting circuits and is available for control purposes which are a function of motor torque. There is also disclosed a method for maximizing useful power output by reducing the phase angle between the motor current and the back EMF. This is accomplished by introducing a delay in commutating the motor windings beyond the occurrence of each back EMF zero-crossing, with the delay being a function of the time between commutations.

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.

An electronically-controlled roll-up window shade that can easily be installed by a homeowner or general handyman is disclosed. The motorized shade includes an internal power source, a motor, and a communication system to allow for remote control of the motorized shade. One or more motorized shades can be controlled singly or as a group. In one embodiment, the motorized shades are used in connection with a zoned or non-zoned HVAC system to reduce energy usage. In one embodiment, the motorized shade is configured to have a size and form-factor that conforms to a standard manually-controlled motorized shade. In one embodiment, a group controller is configured to provide thermostat information to the motorized shade. In one embodiment, the group controller communicates with a central monitoring system that coordinates operation of one or more motorized shades. In one embodiment, the internal power source of the motorized shade is recharged by a solar cell.

Automated shade systems comprise motorized window coverings, sensors, and controllers that use algorithms to control operation of the automated shade control system. These algorithms may include information such as: 3-D models of a building and surrounding structures, shadow information, reflectance information, lighting and radiation information, ASHRAE clear sky algorithms, log information related to manual overrides, occupant preference information, motion information, real-time sky conditions, solar radiation on a building, a total foot-candle load on a structure, brightness overrides, actual and / or calculated BTU load, time-of-year information, and microclimate analysis.

A magnetic drive metering pump in which a movable thrust member fixed to a connecting rod is axially movable in a longitudinal axis in a magnet shroud anchored in a pump housing so that the thrust member with the connecting rod, on electrically driving (actuating) the magnetizing coil, is drawn into the magnet shroud against the force of a recuperating spring, reducing an air gap between the thrust member and an inner face of magnetic shroud, into a bore in the magnet shroud and after deactivating the magnet the thrust member is returned to the starting position by the recuperating spring so that the thrust member and an elastic displacement member actuated thereby on carries out an oscillating motion continued activation and deactivation of the magnetizing coil, which diaphragm cooperates alternately with an outlet and an inlet valve to produce a pump stroke (pressure stroke) and a priming stroke in a metering head arranged in the longitudinal axis. In such a magnetic drive metering pump, a reference element is associated with the module constituted by the thrust member and connecting rod, the position of which reference element is detected by a positional sensor, wherein the positional sensor provides an actual signal which is in a fixed relationship to the position of the reference element, and in that the motion of the unit formed by the thrust member and the connecting rod is influenced as regards control accuracy via a control circuit so that it follows a predetermined nominal profile.