175results about "Electromagnet circuit arrangements" patented technology

Electromechanical lock and method are disclosed. The lock includes: a movable permanent magnet to move between a first position and a second position; a stationary permanent semi-hard magnet; and an electrically powered magnetization coil positioned adjacent to the stationary permanent semi-hard magnet to switch a polarity of the stationary permanent semi-hard magnet between a first magnetization configuration and a second magnetization configuration. The first magnetization configuration of the stationary permanent semi-hard magnet moves the movable permanent magnet to the first position. The second magnetization configuration of the stationary permanent semi-hard magnet moves the movable permanent magnet to the second position. A magnetic axis of the movable permanent magnet is side by side with a magnetic axis of the stationary permanent semi-hard magnet.

A permanent electromagnetic holder 1 is provided with: a first magnet 3 that has a relatively small coercive force; a ring-shaped second magnet 4 that is a rare-earth magnet having a relatively large coercive force; and a coil 5 for magnetizing the first magnet through energization thereof. The first magnet 3 is configured such that the magnetic pole surfaces of different magnetic poles are oriented in the thrust direction of an axial center α, the second magnet 4 is configured such that the magnetic pole surfaces of different magnetic poles are oriented in the thrust direction of an axial center α, and the second magnet 4 is disposed outside the first magnet in the radial direction of the axial center α. The first magnet 3, the second magnet 4, and the coil 5 are arranged so as to overlap in the radial direction of the axial center α, and an operation of switching an adsorption ON / OFF state is carried out by switching the magnetizing direction of the first magnet 3 through energization of the coil 5 when the adsorption ON / OFF state is switched.

A solenoid system and method can include: providing an energizing voltage to a coil of a solenoid; providing an AC signal superimposed onto the energizing voltage; detecting current through the coil including an AC current amplitude induced by the AC signal and including a DC offset current amplitude; determining the AC current amplitude is a low AC current amplitude based on an armature within the solenoid being in a retracted position or determining the AC current amplitude is a high AC current amplitude based on the armature being in an extended position with the control logic, and where the AC current amplitude is determined utilizing the AC signal for synchronous demodulation; and determining a temperature fault based on the DC offset current amplitude falling below a DC offset current amplitude threshold.

Example embodiments are directed a magnetic field generation device including an array of electromagnets including a plurality of electromagnets, and a current controller configured to generate a plurality of current waveforms and to apply each current waveform to a respective one of the plurality of electromagnets. The current controller is further configured to control a pulse duty cycle of each of the plurality of current waveforms. The magnetic field generation device also includes a magnetic field controller configured to calculate each of the plurality of current waveforms to be provided to the respective one of the plurality of electromagnets to generate a desired magnetic field distribution. The plurality of electromagnets include a central electromagnet, and peripheral electromagnets having symmetry in an azimuth direction and arranged about the central electromagnet. Each electromagnet includes a magnetic core and a coil, and a yoke magnetically couples the electromagnets to each other.

To prevent liquid sloshing caused by switching a coil to be energized in a transport device. A transport device that transports an object to be transported provided with a magnetic body, the transport device includes: a plurality of coils configured to generate a thrust for transporting the object to be transported; a coil drive unit configured to apply a pulsed voltage to each of the plurality of coils; and a calculation unit. When switching a coil to be energized, the calculation unit determines a width of the pulsed voltage such that a speed or an acceleration of the object to be transported is stabilized based on a position of the object to be transported and a time at which the object to be transported passes through the position or a current flowing through an energized coil in a predetermined period before switching the coil to be energized, and outputs the determined width to the coil drive unit.

The present disclosure provides a control circuit and a control method of a bistable permanent magnet mechanism. The control circuit includes five switches, a diode and a control unit for controlling the five switches to be turned on and turned off. The control circuit enables the positive and the negative of the current passing through the coil to be adjustable at any time and avoids load breaking, without a complicated design of a driving circuit, thereby reducing the cost. It can also realize PWM control, adapt to a larger current range and different bistable permanent magnet mechanisms, and has a wide range of application scenarios.

The present invention relates to a system and method to control an electric door lock based on a current pulse generator and a switched mode current source with load-dependent output which allows to reduce the size of the installation and the energy needed for the opening / closing of the door and offers the possibility of implementing a rechargeable battery as back up. To do so, the system and method generates 2 sequential current signals after receiving a trigger, wherein one of the signals is a current peak signal with short time duration and the other one a lower but longer in time current signal.

A system in a vehicle includes a panel configured cover a portion of the vehicle through which a port extends and one or more electro permanent magnets arranged on the portion of the vehicle. The system also includes a controller to magnetize the one or more electro permanent magnets based on applying a current of a first polarity to the one or more electro permanent magnets such that the one or more electro permanent magnets on the portion of the vehicle couple to the panel, the panel being metal, or to one or more permanent magnets on a surface of the panel to lock the panel when the panel is in the closed position.

A magnetic field generation module is disclosed. The magnetic field generation module comprises: a main core; at least two auxiliary cores positioned in the vicinity of and around the main core; auxiliary coils wound on respective auxiliary cores; and a power source unit for applying a current to the auxiliary coils.

Provided is a control device controlling an electromagnetic actuator that drives an operation device, supported in an elastically vibratable manner by an elastic support part, in one direction of a vibration direction of the operation device to vibrate. The control device includes a circuit that applies a main driving signal to a coil of the electromagnetic actuator to start vibration of the operation device in response to a touch operation on the operation device, then applies a sub-driving signal to the coil to adjust an attenuation period of the vibration. The sub-driving signal has a variable voltage varying with an offset voltage, as a center value, offset from a zero voltage, and a waveform that indicates a variation in the variable voltage is a sine function curve or a cosine function curve. The circuit applies the sub-driving signal while changing the offset voltage for each cycle.

A method for a power system is disclosed. The method includes receiving signals, activating switches to pass a current from a power source to an apparatus. The method also includes deactivating switches and bypassing the power source. The power source may be a photovoltaic power source. The signals may be power line communication (PLC) signals.

To prevent liquid sloshing caused by switching a coil to be energized in a transport device. A transport device that transports an object to be transported provided with a magnetic body, the transport device includes: a plurality of coils configured to generate a thrust for transporting the object to be transported; a coil drive unit configured to apply a pulsed voltage to each of the plurality of coils; and a calculation unit. When switching a coil to be energized, the calculation unit determines a width of the pulsed voltage such that a speed or an acceleration of the object to be transported is stabilized based on a position of the object to be transported and a time at which the object to be transported passes through the position or a current flowing through an energized coil in a predetermined period before switching the coil to be energized, and outputs the determined width to the coil drive unit.

The present invention provides a method and a corresponding device for controlling a micro-nanorobot cluster, which adopts a driving method based on a rotating gradient magnetic field to drive a micro-nanorobot cluster with magnetic components as a carrier for precise drug or cell delivery. The present invention uses a plurality of electromagnetic coils driven by a programmable timing electrical signal, which can generate an equivalent centripetal force pointing to the target position in the working space area, thereby attracting the micro-cluster to converge from different directions to the target position including the diseased tissue. By changing the current input of the electromagnetic coil, the coordinates of the target position can be adjusted.

To provide an improved method for operating a multi-frequency metal detector and an improved multi-frequency metal detector to be operated according to this method.SOLUTION: A metal detector (1) comprises: a drive coil (L61) for producing an electromagnetic field in a product; at least one detection coil (L62, L63) arranged to detect fluctuations in the magnetic field caused by metallic particles present in the product; and a multifrequency transmitter unit (10) comprising a converter (4) with a plurality of drive switches (S41, S42; S43, S44). The plurality of drive switches (S41, S42; S43, S44) is driven by a drive controller (2) according to operating instructions such that the drive switches (S41, S42; S43, S44) alternately conduct a drive current (iD) through the drive coil (L61) so that the generated electromagnetic field exhibits two or more different frequency components (fD1, fD2).SELECTED DRAWING: Figure 1a

An apparatus comprising a signal transformer coupled to a power line and a signal transmission, reception, or detection circuit. A sensor is configured to be responsive to the power line current or magnetic flux generated in a ferrite core of the signal transformer. When the sensor indicates that the flux generated by the power line current mat cause an attenuation of the signal strength, a second circuit generates a current through a flux cancelling winding that cancels at least some of the flux generated by the power line current.

The present invention provides a switch mechanism for use in a charging device, the charging device comprising an upper shell and a lower shell, the switch mechanism comprising a first magnetic member disposed within the upper shell, a second magnetic member disposed within the lower shell, and a control unit disposed within the upper shell or the lower shell; the control unit is configured to control the magnetic force relationship between the first magnetic member and the second magnetic member, thereby automatically controlling the connection relationship between the upper shell and the lower shell; there is no need to manually change the magnetic force relationship between the first magnetic member and the second magnetic member, the device is easy to use, and the user experience is enhanced. The present invention also provides a charging device provided with the switch mechanism, and a method for controlling the switch mechanism.

The application discloses a magnet retaining device for electromagnet during power failure, which comprises a main circuit, a control circuit and a communication module, wherein a rectifying unit and a programmable controller are respectively connected with the communication module; a three-phase AC power supply is connected to the primary side of a transformer through a circuit breaker; the secondary side of the transformer is connected to the rectifying unit through a fuse, a fuse and an AC contactor; the rectifying unit outputs a DC voltage; the electromagnet is connected to the rectifying unit through a fuse and a diode module; the electromagnet is forwardly excited to work; the rectifying unit outputs a positive DC voltage; the electromagnet is connected to the rectifying unit through a fuse and three normally open contacts of an AC contactor connected in parallel with the diode module. The magnet retaining device for electromagnet during power failure realizes four-quadrant operation of the electromagnet, energy storage and rapid release of the electromagnet, and magnet retaining operation during power failure. When the rectifying unit cannot feed back operation, the energy storage of the electromagnet can be released through an added freewheeling circuit.

The actuator comprises a movable armature (2) rotating relative to a stator (1) having flanges (3a, 3b) on which magnets (5a, 5b) are mounted, a coil (9a, 9b) being mounted around one of the flanges (3a). The magnets (5a, 5b) have an axial magnetization in the z-axis and are aligned in the x-axis. The movable armature (2) is arranged between the magnets (5a, 5b) in the x-axis. The movable armature (2) is mounted on a guide (11) rotating around a y-axis perpendicular to the x- and z-axes. The movable armature (2) is separated from the magnets (5a, 5b) by air gaps (6a, 6b). Each magnet (5a, 5b) forms a static magnetic circuit (8a, 8b) with one end (2a, 2b) of the movable armature (2) and one of the flanges (3a, 3b). The coil (9a, 9b) forms a dynamic magnetic circuit with the ends (2a, 2b) of the movable armature (2) and the flanges (3a, 3b).

Electromagnetic replication wherein there is no detectable voltage when an inductor coil is subjected to a magnetic field, the amount of current is proportional to the mass of the material in circumference and the strength of the magnetic field, as long as no resistance interferes there will be no voltage. Voltage only starts to show when resistance is present. When a primary coil in a first magnetic core has a current, it also produces a magnetic field. That magnetic field will cause another current and magnetic field in a corresponding second magnetic core. When the inductor coil forming the magnetic core forms a closed loop, the magnetic field and current produces will be a replication of the primary coil. By attaching another coil to the secondary and not having resistance, the attached coil will also have the same current and magnetic field and the same process starts over.

A power control system for use with an electric lock mechanism including an actuator having a coil with a particular coil impedance. The power control system comprises a power supply configured to provide an output voltage having a drive current to the actuator, a credential device powered by the power supply and configured to signal the power supply to provide the output voltage upon receiving an authorized access code, an actuator driver including a multiple-gain current-sensing circuit, and a microcontroller configured to monitor and control the power supply, credential device, actuator driver, and actuator, and determine the impedance of the coil. The microcontroller is populated by a look-up table having performance data for a plurality of coils such that the microcontroller selects a duty ratio to establish the optimum magnitude of drive current to the coil based only on the determined impedance of the coil.

The invention relates to a circuit for controlling a current through a relay coil, comprising an electronic switch for controlling the current through the relay coil and a comparator for controlling a control voltage applied to a control terminal of the electronic switch, a first voltage being applied to a first input terminal of the comparator, and a second voltage being applied to a second input terminal of the comparator. A second voltage is applied to the second input of the comparator, said second voltage being derived from the current through the relay coil, and the circuit is designed to reduce the current through the relay coil to a holding current after a switching process caused by a switching current through the relay coil.

A vehicle, comprising: a frame; a passenger compartment including a selected region suitable for presence of people; an electric motor that, when in operation is associated with an undesired magnetic field emitted into the selected region; a magnetic field generator positioned in at least one of a passenger seat, a vehicle door, or the frame, wherein the magnetic field generator is configured to at least reduce the undesired magnetic field in the selected region; a magnetic field sensor configured for sensing the undesired magnetic field emitted into the selected region; and a circuit configured to: receive from the magnetic field sensor sensing data indicative of the undesired magnetic field; determine a cancelation magnetic field for at least reducing the undesired magnetic field; and direct electrical signals to the magnetic field generator for generating the cancelation magnetic field for at least reducing the undesired magnetic field.

Systems, methods, and computer readable medium are provided for reducing an undesired magnetic field generated by an electric motor of a vehicle. Reducing an undesired magnetic field generated by an electric motor of a vehicle includes receiving from at least one magnetic field sensor sensing data indicative of the undesired magnetic field emitted into a selected region of a passenger compartment of the vehicle; determining a cancelation magnetic field for at least reducing the undesired magnetic field emitted by the electric motor into the selected region; and directing electrical signals to at least one magnetic field generator positioned in at least one of a passenger seat, a vehicle door, or a frame of the vehicle, for causing the at least one magnetic field generator to generate the cancelation magnetic field for at least reducing the undesired magnetic field emitted by the electric motor through the selected region.

The magnetic valve controls the flow of fluid through a tube. The valve includes a first diode and a first solenoid connected between a first terminal and a second terminal, a second diode and a second solenoid connected in parallel with the first diode and the first solenoid between the first terminal and the second terminal, the second diode being disposed in anti-parallel with the first diode, and a ferrous ball moving between an open position and a closed position. The first solenoid generates a first magnetic field in response to a control signal having a first polarity applied to the first terminal and the second terminal to move the ferrous ball toward the first solenoid to an open position allowing fluid flow, and the second solenoid generates a second magnetic field in response to a control signal having a second polarity to move the ferrous ball toward the second solenoid to a closed position blocking coolant flow, the second polarity being opposite the first polarity.

A control device (1) for controlling an RMS value of an electrical load current (5) at a time-varying load (2), characterized in that the control device (1) is configured to provide a voltage pulse train (4) having a predetermined duty cycle (10) at the time-varying load (2) and in at least one pulse phase (8) of the voltage pulse train (4): - to detect a respective sample value (16) of the electrical load current at the time-varying load (2), wherein the control device (1) is configured to detect the sample value (16) of the electrical load current in a last tenth of the pulse phase (8) and / or during a falling signal edge of a pulse of the voltage pulse train (4), - to determine an actual RMS value (11) of the electrical load current assigned for the sample value (16) of the electrical load current by means of a dependency (17) stored in the control device (1).- to determine a difference value (25) between the actual RMS value (11) of the electrical load current and a target RMS value (6) of the electrical load current, - to determine an adapted duty cycle (26) of the voltage pulse train from the difference value (25) of the electrical load current according to a predetermined procedure, and - to provide an adapted voltage pulse train (27), having the adapted duty cycle (26), to the time-varying load (2).

Magnetic coupling devices may include movable pole portions. The movable pole portions may be retractable along a first direction and may be locked into place. In an exemplary embodiment of the present disclosure magnetic coupling device for magnetically coupling to a ferromagnetic workpiece is provided. The magnetic coupling device comprising: a housing; a switchable magnetic flux source supported by the housing; and a plurality of pole portions. The switchable magnetic flux source being switchable between at least an OFF state and at least one of a partial ON state and an ON state. Each including at least one workpiece interface having a workpiece engagement surface. The plurality of-pole portions including a first pole portion including a first workpiece interface having a first workpiece engagement surface and a second pole portion including a second workpiece interface having a second workpiece engagement surface.

A circuit includes an amplifier having a first input, a reference input, and an output. A pulse width modulator (PWM) controller has an input coupled to the output of the amplifier. A first switch has a control terminal coupled to an output of the PWM controller. A second switch has a second terminal coupled to the second terminal of the first switch, and has a control terminal coupled to the output of the PWM controller. An input of a current sensor is coupled to the second terminal of the first switch and is coupled to a second terminal of the second switch. An output of the current sensor is coupled to the first input of the amplifier. A duty cycle monitoring and reference signal adjustment circuit has an input coupled to the output of the PWM controller and has an output coupled to the reference input of the amplifier.

A selectively repositionable airbag module for a vehicle includes a housing having enclosable side walls defining an interior zone. The enclosable side walls include a support surface. An airbag is arranged in the interior zone. A connector system is mounted at the support surface. The connector system includes one or more connector elements that extend through the support surface to connect the housing to a vehicle floor.

An electropermanent magnet array is provided. The electropermanent magnet array includes one or more of a plurality of electropermanent magnets of common length, arranged in a parallel fashion, and a planar pole piece, coupled to the first ends of the plurality of electropermanent magnets. Each electropermanent magnet includes a first and a second end opposite the first end.

In an aspect, there is provided a method of operating a pulse width modulation (PWM) valve for a fluid application of an agricultural implement. The method includes applying full current for a first period of time to fully open the PWM valve, applying a reduced current for a reduced current value that is from 0 up to a dissipating threshold value that is below full current for a second period of time to rapidly dissipate energy in the PWM valve that is fully open, and applying a holding current for a third period of time to hold the PWM valve fully open for the fluid application.