1765 results about "Rotating magnetic field" patented technology

An improved interrogator for an inductively coupled identification system is disclosed. The interrogator provides a multidimensional electromagnetic field through a plurality of coils aligned relative to each other. The coils provide a rotating magnetic field having approximately constant amplitude regardless of orientation with respect to the transponder. An additional coil may be utilized to precess the multidimensional electromagnetic field. The interrogator may further provide an impedance matching network that includes a series drive capacitor to match the impedance of a capacitor in parallel with a coil to a driver load impedance.

Provided is a tracking system, including a motor coupled to a medical instrument and configured to generate at least one magnetic field, and at least one receiver coil configured to sense the magnetic field. Also provided is a method of tracking, including rotating a rotor of a motor, wherein the rotor comprises a permanent magnet that generates a rotating magnetic field when the rotor is rotated, sensing the rotating magnetic field with at least one receiver, transmitting to a processor a signal indicative of the rotating magnetic field, and processing the signal to determine a position of the motor. Further provided is a method of tracking, comprising energizing a stator coil of a motor to generate at least one magnetic field, sensing the at least one magnetic field with at least one receiver, transmitting to a processor a signal indicative of the at least one magnetic field, and processing the signal to determine a position of the motor.

A method and apparatus for intravascular imaging utilizes a rotating magnetic field generated outside of the patient's body to cause a substantially synchronous rotation of an ultrasonic signal inside the patient's body.

A magnetic actuation urethral valve is adapted for inserting into the urethra of a patient who suffering from urinary incontinence in order to recover control of urine flow. The valve member is driven by a magnet rotor which is magnetically actuated by a rotating magnetic field generated from a controller outside the body. There is also an actuation device for the user to discharge by inserting an indwelling catheter into the valve in case the valve does not work for any reason.

A control apparatus for a brushless DC motor that rotatably drives the brushless DC motor including a rotor having a permanent magnet, and a stator having stator windings of a plurality of phases that generate a rotating magnetic field for rotating the rotor, by a current passage switching device constituted by a plurality of switching elements and performing successive commutation of current to the stator windings. The control apparatus includes: an angular error calculation device for calculating a sine value and a cosine value of an angular difference between an estimated rotation angle with respect to the rotation angle of the rotor and an actual rotation angle, based on a line voltage that is a difference between phase voltages of the plurality of phases on an input side of the stator winding and phase currents of the plurality of phases; and an observer for calculating the rotation angle of the rotor based on the sine value and the cosine value of the angular difference.

An angle detection unit including first to third arithmetic units receives first and second signals that are associated with intensities of components of a rotating magnetic field in mutually different directions. The first arithmetic unit generates a sum of squares signal made up of the sum of squares of the first and second signals. Based on the sum of squares signal, the second arithmetic unit calculates a first error component estimate which is an estimated value of a first error component included in the first signal and a second error component estimate which is an estimated value of a second error component included in the second signal. The third arithmetic unit generates a first corrected signal by subtracting the first error component estimate from the first signal, generates a second corrected signal by subtracting the second error component estimate from the second signal, and calculates a detected angle value based on the first and second corrected signals.

Methods are disclosed for the capture, detection, separation, isolation and quantification of contaminants in a starting material. Also disclosed are competitive assay methods for the detection and quantification of contaminants in a starting material. Kits for use with the method are disclosed as well. A system for capturing, separating and/or concentrating contaminants from a material is also presented. The system captures, separates and/or concentrates contaminants such as bacteria, viruses, other microorganisms, and/or larger items, such as insects, from a variety of materials, such as food, and environmental and clinical materials. In general, the system uses a rotating magnetic field to mix the material with magnetic particles to capture the target contaminants, and a fixed magnetic field to separate and concentrate the captured target contaminants.

A permanent-magnet rotating machine includes a rotor having a rotor core carrying on its curved outer surface multiple permanent magnets arranged in two rows along an axial direction in such a manner that the permanent magnets in one row are skewed from those in the other row in a circumferential direction by a row-to-row skew angle (electrical angle) thetae, and a stator having a cylindrical stator core in which the rotor is disposed, the stator core being provided with stator coils for producing a rotating magnetic field for rotating the rotor. A lower limit of the row-to-row skew angle thetae is set at a value larger than 30 degrees (electrical angle). A cogging torque ratio, or the ratio of a cogging torque occurring in the absence of skew to a cogging torque occurring when the permanent magnets are skewed, at a row-to-row skew angle of 30 degrees is calculated based on the relationship between the cogging torque ratio and the row-to-row skew angle thetae and B-H curve properties of the stator core, and an upper limit of the row-to-row skew angle thetae is set at a value not larger than its maximum value at which the cogging torque ratio does not exceed the calculated cogging torque ratio at 30 degrees.

A synchronous AC motor has a stator with stator poles arranged as a plurality of circumferentially extending stator pole groups, with each stator pole group having a pair of corresponding circumferentially extending loop-configuration stator windings disposed adjacent on either side or a single such winding disposed adjacent at one side, adjacent stator pole groups being mutually circumferentially displaced by a fixed amount corresponding to a specific electrical phase angle. A rotating magnetic field is produced by applying respective polyphase AC voltages to the windings, such that currents of mutually opposite direction flow in each pair.

The present invention provides a charger for inductively charging one or more battery powered appliances simultaneously. The charger comprises an external unit adapted to inductively provide power to the battery powered appliances, the external unit comprising: two or more primary coil pairs that are arranged in a circular pattern; an AC power source for providing an alternating current (AC) to the primary coil pairs for generating a rotating magnetic field between respective primary coils of the primary coil pairs; and a processor for driving the AC power source, wherein the one or more battery powered appliances are adapted to be arranged inside the circular pattern of the external unit, each appliance comprising a secondary coil for enclosing part of the magnetic field and in response generating a current for charging the battery of the appliance.

A magnetic sensor comprising a bridge circuit in which four magnetoresistive devices are connected, the magnetoresistive device comprising a spin-valve, giant-magnetoresistive film comprising a pinned layer having unidirectional magnetic anisotropy, a free layer whose magnetization direction is rotated in alignment with an external magnetic field direction, and an intermediate layer sandwiched by the pinned layer and the free layer, and at least one of the magnetoresistive devices meeting the condition of 36°≦θ<45°, wherein θ is an acute angle between its longitudinal direction and the magnetization direction of the pinned layer.

The disclosed invention provides apparatus, systems, and methods for moving an object in an enclosed area using a magnetic dipole deployed in the enclosed area and thereafter applying an external rotating magnetic field for applying a rotational force to the dipole along one or more selected axis. The external magnetic field is moved to manipulate object in the desired direction(s) of movement.

An improved motorized axle system for use in vehicles comprising:

• a first motorized axle and a second motorized axle;
• the first motorized axle is larger than the second motorized axle;
• each motorized axle comprises: a stator block, a stator, a rotor, at least two bearings, and an axle;
• the stator block comprising an upper member and a lower member for use in providing a housing for the stator and rotor;
• the stator comprising at least one armature coil for forming a rotating magnetic field;
• the rotor comprising a set of permanent magnets;
• the axle comprising an axle drive line having a first end and a second end, the axle drive line being elongate and adapted to define the width of a vehicle;
• the bearings are disposed around the rotor shaft circumferentially.

The invention provides a method for continuously producing particle reinforced metal matrix composites in an industrial scale, which adopts the synthesis of metal matrix composites in a combination magnetic field. The method is characterized in that: the combination of a rotating magnetic field and a travelling wave magnetic field is adopted to synthesize a preparation particle reinforced metal matrix composite fused mass in the in-situ synthesis process of composites. The low frequency rotating magnetic field is placed at the outer side of a composite material molten pool, and the center of a coil of the magnetic field and the center of the fused mass are at the same height; and the travelling wave magnetic field is exerted at the bottom part of the composite material molten pool, and the coil center of the travelling wave magnetic field and the center of the composite material molten pool are at the same position. The composite material particle reinforced phases prepared by the method are distributed evenly and thinned, interior tissues are compact and have no structural defects such as loosening and hole shrinkage, the degree of finish of external surfaces of casting blanks is high, defects are eliminated, and the friction resistance and the abrasion resistance of the composites are obviously improved.

An electric pump includes a stator, a rotor, a shaft, a bearing part, and a pump unit. The stator has a magnetic part, and the stator forms a rotation magnetic field when a coil of the stator is energized. The bearing part has a longitudinal central position that is positioned on an imaginary plane perpendicular to a rotation axis of the rotor. The imaginary plane is positioned within an inner range defined between longitudinal end portions of the magnetic part of the stator.

The invention pertains to the technical field of medical engineering and discloses a method for driving and controlling a universally rotating magnetic field of a medical micro-robot in a human body. The method is characterized in that three groups of Helmholtz coils on z, y and x axes are arranged by orthogonal nesting so as to ensure that respective combined inductance is equal and the amplitude of intensity of magnetization of a harmonic magnetic field generated respectively is equal when the three groups of coils are driven by the same harmonic current. The relevant amplitude of an axis azimuth angle of the robot and a same frequency sine harmonic driving current of a phase are overlapped to form a spatial universally and evenly revolving magnetic field corresponding to the revolving axis of the azimuth angle in a certain space surrounded by the orthogonal Helmholtz coils on the three axes. The self-rotating direction of the universally rotating magnetic field can be changed by changing the current frequency to adjust the revolution of the magnetic field and changing the orthogonal Helmholtz coils on the three axes to drive the current direction. The method of the invention has the beneficial effects that the method is applicable to a bending inner environment of the human body and can realize a plurality of functions of rotation, going forward and backward and speed adjusting, etc., of the robot in the human body, and the positioning operation in the human body.