2725results about "Ac motor stoppers" 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.

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.

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 motor drive system for a sensorless motor includes a catch start sequencer that controls the motor drive system to robustly start the motor in the event the motor rotor is rotating in forward or reverse direction prior to activating the motor drive system. In particular, the catch start sequencer causes the motor drive system to initially find and track the rotor position, and then determines the speed and possibly the direction of rotation of the rotor. If the rotor is rotating in the reverse direction, the catch start sequencer controls the motor drive system to slow the speed of rotation and to then start the rotor rotating in the forward direction.

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.

A disk drive is disclosed wherein a BEMF speed error is measured during a BEMF spindle speed control mode, and a spindle control current is updated in response to the BEMF speed error to drive the disk at an operating speed. A reference time period (RTP) is calibrated, and a sinusoidal error in a wedge time period (WTP) due to eccentricity in the disk rotating is estimated to generate an eccentricity compensation value. After switching to a wedge spindle speed control mode, an actual WTP is detected and a wedge speed error is generated in response to the RTP, the detected actual WTP, and the eccentricity compensation value. The disk is then maintained at the operating speed by updating the spindle control current in response to the wedge speed error.

A wireless operating system (10) utilizing a multi-functional wall station (12) for a motorized door / gate operator includes an operator (50) for controlling the movement of a door / gate (54) between various positions. The system has an operator with a receiver (56) and a wall station transmitter (12) for transmitting a signal (42) to the receiver. The signal initiates separate operator functions in addition to opening and closing of the door / gate. A remote transmitter (70) may send a remote signal (74) received by the receiver, wherein the receiver is capable of distinguishing between the wall station signal (42) and the remote signal (74). The wall station includes a transmitter programming button (24), wherein actuation of the transmitter programming button places the wall station transmitter in a learn mode, and wherein subsequent actuation of the remote transmitter positively identifies the remote transmitter for use with the wall station. A light (66) powered by the operator and a light actuation button (18) provided by the wall station transmitter is included in the system. Actuation of the light actuation button (18) functions to switch the light on or off. A pet height button (22), provided by the wall station transmitter, selectively positions the height of the gate / door (54) from its fully closed position to allow ingress and egress of a pet. A delay-close button (20) closes the door / gate after a predetermined period of time. Actuation of a door installation button (28) sequences the door / gate and said operator through various operational parameters to establish a door operating profile. A keyless entry transmitter (80) and a second wall station may also control the operator.

A change-over device of pull cord control and wireless remote control for a DC brushless-motor ceiling fan is to have a driver installed in a ceiling fan basic body, and the driver has a detecting unit for detecting whether or not a connector positioned in a hanging bell is connected with a wireless control switch unit so as to control the blades of the DC brushless-motor ceiling fan to rotate by pull cord control or by wireless remote control. Further, the connector is installed inside the hanging bell; therefore, when the DC brushless-motor ceiling fan is to be additionally provided with a wireless control switch unit, it is convenient and safe in installation.

A variable speed wind turbine having a doubly fed induction generator (DFIG), includes an exciter machine mechanically coupled to the DFIG and a power converter placed between a rotor of the DFIG and the exciter machine. Thus, the power converter is not directly connected to the grid avoiding the introduction of undesired harmonic distortion and achieving a better power quality fed into the utility grid. Moreover, the variable speed wind turbine includes a power control and a pitch regulation.

A permanent magnetically excited electrical rotary drive for a blood pump is proposed, comprising a permanent magnetic rotor and a stator, said stator comprising a drive winding having at least two loops for the production of a magnetic drive field which produces a torque on the rotor, with each loop belonging to a different electrical phase, furthermore comprising a setting device which supplies each loop in each case with a phase current or in each case with a phase voltage as a setting parameter, with the setting device comprising a separate power amplifier for each loop so that the setting parameter for each loop can be regulated independently of the setting parameter for the other loops.

A disk drive is disclosed comprising a disk, a head actuated over the disk, and a spindle motor for rotating the disk, the spindle motor comprising a plurality of windings. Disk control circuitry executes a spin-down operation of the spindle motor by estimating an angular position of the spindle motor by applying a voltage to at least one of the windings and evaluating a rise time of current flowing through the winding. The windings are commutated in response to the estimated angular position, and a driving current is applied to the windings to brake the spindle motor.

A disk drive is disclosed comprising a spindle motor having a plurality of windings including at least a first winding, a second winding, and a third winding. During a spin-up operation, a voltage is applied to the first winding and a first rise time is measured for current flowing through the first winding to reach a predetermined threshold. A voltage is applied to the second winding and a second rise time is measured for current flowing through the second winding to reach a predetermined threshold. A voltage is applied to the third winding and a third rise time is measured for current flowing through the third winding to reach a predetermined threshold. A difference is computed in response to the first rise time, the second rise time, and the third rise time, and an angular position of the spindle motor is estimated by computing an arctangent in response to the difference.

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.

An apparatus for the thermal regulation of an AC drive for providing power to a motor includes a temperature sensor producing a signal indicative of temperature, a heater resistor connectable across a DC link of the AC drive, and a first switch. A controller is operable to monitor the temperature signal and control the first switch to provide power via the DC link to the heater resistor if the sensed temperature is below a predetermined setpoint.

Time-of-flight (TOF) three-dimensional sensing systems are deployed on or in a motor vehicle to image contact zones associated with potential contact between an avoidable object and the vehicle or vehicle frame and / or remotely controllable motorized moving door or liftgate. An algorithm processes depth data acquired by each TOF system to determine whether an avoidable object is in the associated contact zone. If present, a control signal issues to halt or reverse the mechanism moving the door. A stored database preferably includes a depth image of the contact zone absent any object, an image of the door, and volume of the door. Database images are compared to newly acquired depth images to identify pixel sensors whose depth values are statistically unlikely to represent background or the door. Pixels within the contact zone so identified are an object, and the control signal is issued.

A load control system provides for automatically controlling a position of a motorized window treatment to control the amount of sunlight entering a space of a building through a window located in a façade of the building in order to control a sunlight penetration distance within the space and minimize occupant distractions. The load control system automatically generates a timeclock schedule having a number of timeclock events for controlling the position of the motorized window treatment during the present day. A user is able to select a desired maximum sunlight penetration distance for the space and a minimum time period that may occur between any two consecutive timeclock events. In addition, a maximum number of movements that may occur during the timeclock schedule may also be entered. The load control system uses these inputs to determine event times and corresponding positions of the motorized window treatment for each timeclock event of the timeclock schedule.

A powered tool for performing surgical procedures. The tool includes a handpiece in which a power generating unit is housed. A control member is mounted to the handpiece. The control member is mounted to the handpiece so that the orientation of the control member can be selectively set relative to the point to which it is mounted to the handpiece and so it can move relative to a reference point on the handpiece. A control module monitors the orientation of the control member and its position relative to the reference point. Based on the control member orientation and position, the control module generates signals to regulate the operation of the power generating unit. When the power generating unit is a motor, the control module generates signals to ensure that the maximum speed at which the motor can be driven is less than the no load speed.

An electric drive apparatus and method for controlling medium-voltage alternating current motors wherein a multi-phase power transformer having multiple secondary windings provides multi-phase power to multiple power cells which provide four quadrant operation. Each power cell has a single-phase output and is controllable by a modulation controller. The power cells are connected in series thus permitting the maximum output voltage for each cell to be less than the maximum line-to-line voltage. Each power cell can have a rectifier portion to convert input AC-to-DC, capacitors, an output DC-to-AC inverter, a regenerative bridge converter connected in parallel with the rectifier portion and a local modulation controller connected to a master controller.

A door operator for controlling operation of a door, the door operator having a motor to open the door against a spring force, the door operator further comprising a door position sensor for transmitting a signal indicative of door position; and among other things, calculates a door moment of inertia based on a net torque and the time for the door to reach a predetermined angle from the closed position. Also provided is a door operator that compares door speed to a desired door speed based on a door speed-position profile and generates a door speed error signal and minimizes the door speed error signal by adjusting the braking load resulting from charging a chargeable battery using the motor as a generator.

A system for operating a barrier system such as a garage door, gate or fence. A DC motor is connected to and operates a barrier drive. A power amplifier is configured to receive power signals from a power supply and to output modulated DC signals to the DC motor. A controller implements an intelligent closed-loop motion control algorithm to control the power amplifier according to a non-linear motion profile. A feedback sensor provides status signals to the controller to determine position or speed of the barrier.

An apparatus for generating a number of loudspeaker signals for a loudspeaker array defining a reproduction space includes a prestage configured to generate a plurality of output audio signals while using one or more audio signals associated with one or more virtual positions, each output audio signal being associated to a loudspeaker position such that the plurality of output audio signals together replicate a reproduction of the input audio signal(s) at the virtual position(s), and a number of output audio signals being smaller than a number of loudspeaker signals. The apparatus further includes a main stage configured to obtain the plurality of output audio signals and further to obtain, as a virtual position for each output audio signal, the loudspeaker positions, and to generate the number of loudspeaker signals for the loudspeaker array such that the loudspeaker positions are replicated as a virtual sources by the loudspeaker array.

Drive circuit for a blower motor employs a microprocessor control element, a controlled rectifier to provide DC power at a controlled rail voltage, and an inverter employing a pair of switching transistors arranged as a bridge inverter or half-bridge inverter. The drive circuit operates over a range of blower speeds and varies both the frequency and amplitude of bipolar pulses that are applied to the blower motor armature.