332 results about "Choke" patented technology

A petroleum well has an electronic module and a number of sensors which communicate with the surface using the tubing string and casing as conductors. Induction chokes at the surface and downhole electrically impede AC flow through the (tubing or casing if so configured) with the resulting voltage potential useful for power and communication. A high bandwidth, adaptable spread spectrum communications system is used to communicate between the downhole electronics module and a surface master spread spectrum modem. Downhole sensors, such as pressure, temperature, acoustic and seismic sensors accurately assess downhole physical conditions. In a preferred form, the electronics module and sensors are wireline insertable and retrievable into a side pocket mandrel in the tubing string. Permanent downhole sensors that can communicate with the surface allow such diverse applications as optimizing well and field performances, monitoring and assessing the geophysics of the fomrations around the well, assessing well and reservoir reserves, assessing reservoir conditions.

A lead for an electronic device which resists the induction of a current from an electromagnetic field external to said lead includes one or more pairs of adjacent segments of electrical wire, each of the pairs including a first segment of electrical wire and a second segment of electrical wire. The lead also includes one or more shielded RF chokes, wherein each of the shielded RF chokes is provided between the first segment of electrical wire and the second segment of electrical wire of a respective one of the one or more pairs of adjacent segments. Also, an implantable device that includes a generator for generating one or more electrical pulse and a lead as described for delivering the pulses to tissue within a patient's body. A method for making the described implantable device is also provided.

Various high-strength microwave antenna assemblies are described herein. The microwave antenna has a radiating portion connected by a feedline to a power generating source, e.g., a generator. The antenna is a dipole antenna with the distal end of the radiating portion being tapered and terminating at a tip to allow for direct insertion into tissue. Antenna rigidity comes from placing distal and proximal radiating portions in a pre-stressed state, assembling them via threaded or overlapping joints, or fixedly attaching an inner conductor to the distal portion. The inner conductor is affixed to the distal portion by, e.g., welding, brazing, soldering, or by adhesives. A junction member made from a hard dielectric material, e.g., ceramic, can be placed between the two portions and can have uniform or non-uniform shapes to accommodate varying antenna designs. Electrical chokes may also be used to contain returning currents to the distal end of the antenna.

A FET amplifier which minimizes the worsening of the distortion-susceptibility due to variations in the ambient temperature of operation is to be provided. An LDMOS FET 1, whose source terminal is grounded and to which are applied a gate voltage Vgs from a gate bias terminal 3 via a temperature-compensating circuit 2 and a choke coil and a drain voltage Vds from a drain bias terminal 4 via a choke coil operates as a source-grounded type amplifier. In the temperature compensating circuit 2, the resistances of fixed resistance elements 21 and 22 connected in parallel are set to be the same or have the same number of digits, and those of thermosensitive resistance elements (thermistors) 23 and 24 are set to be a combination of a value greater by one digit and a value smaller by one digit than that of the fixed resistance element 21 or the fixed resistance element 22 at the standard level (+25° C.) in the ambient temperature range of operation.

Two power modules, in which switching elements for switching over currents supplied to coils of a motor are resin-molded, are provided to face each other sandwiching a plane including a rotation axis of a shaft. A first smoothing capacitor, second smoothing capacitors and a choke coil are located between the power modules. By consolidating large-sized electronic parts between the power modules, a control unit can be reduced in size and impedance of electric conductor connecting the electronic parts and the power modules can be reduced.

An advanced modular plug connector assembly incorporating an insert assembly disposed in the rear portion of the connector housing. In one embodiment, the connector has a plurality of ports in multi-row configuration, and the insert assembly includes a substrate adapted to receive one or more electronic components such as choke coils, transformers, or other signal conditioning elements or magnetics. The substrate also interfaces with the conductors of two modular ports of the connector, and is removable from the housing such that an insert assembly of a different electronics or terminal configuration can be substituted therefor. In this fashion, the connector can be configured to a plurality of different standards (e.g., Gigabit Ethernet and 10 / 100). In yet another embodiment, the connector assembly comprises a plurality of light sources (e.g., LEDs) received within the housing. Methods for manufacturing the aforementioned embodiments are also disclosed.

A shortened multi-band antenna includes in-line dipoles, selected elements of which having shielded meanderline chokes to be able to switch from an extended dipole at the lower VHF frequencies to a shortened dipole for the UHF band. Additionally, the staggered asymmetric meanderline configuration permits overall size reduction, whereas antenna construction includes an intermediate fiberglass layer over which conductive foil is placed for tuning and for parasitic radiator purposes to improve the gain of the UHF dipole in the upper regions of the band at 450 megahertz. Additionally, at the low end of the 30 megahertz band a sleeve is positioned between the base of the lowest dipole element and ground, with the sleeve provided with two parallel RLC circuits tuned to different bands to improve VSWR at the low end of the VHF band and to eliminate unwanted nulls.

A magnetic composite for AC applications with improved magnetic properties (i.e. low hysteresis losses and low eddy current losses) is disclosed. The composite comprises a consolidation of magnetizable metallic microlamellar particles each having a top and bottom surfaces and opposite ends. The top and bottom surfaces are coated with a dielectric coating for increasing the resistivity of the composite and reducing eddy current losses. The dielectric coating is made of a refractory material and the ends of the lamellar particles are metallurgically bonded to each other to reduce hysteresis losses of the composite. A process for manufacturing the same is also disclosed. The composite is suitable for manufacturing devices for AC applications such as transformers, stator and rotor of motors, generators, alternators, field concentrators, chokes, relays, electromechanical actuators, synchroresolvers, etc . . . .

The invention relates to an integrated magnetic component for a switched mode power converter, which includes a transformer with two transformer core elements (E2, E3) and at least one choke core element (E1, E4). Each core element (E1, E2, E3, E4) comprises two outer legs (120a, 120b) and a flange (122) which connects the outer legs (120a, 120b) to form U-like core elements. Each choke core element (E1, E4) abuts a flange (122) of one of the transformer core elements (E2, E3). The integrated magnetic component (103) includes a first choke winding (123) arranged on a leg (121.1) of a choke core element (E1) and a second choke winding (124) arranged on another leg (121.4) of a choke core element (E4), where one of a primary (P1, P2) or a secondary winding (S1, S2) of the transformer is connected between the choke windings (123, 124) and where all windings (P1, P2, S1, S2, 123, 124) are interconnected to reduce core losses by flux compensation in order to increase power density.

A switch mode power converter provides high efficiency at light and no load conditions by utilizing a variable inductance swinging choke at the output of a synchronous rectifier. The use of the swinging choke with a synchronous rectifier eliminates power inefficiencies caused by currents that circulate from the output capacitance to the input capacitance during no load conditions.

The purpose of this invention is to provide a common-mode choke coil that inhibits mode conversion and a method for manufacturing said common-mode choke coil. Said common-mode choke coil (1) comprises a core, which has a winding-core section (14), and windings (20 and 21). A wire-start region (alpha) extends from one end (A) where one winding (20) contacts the winding-core section (14) to a given position (B), and a wire-end region (beta) extends from the other end (C) where the other winding (21) contacts the winding-core section (14) to another given position (D). With respect to an x-axis, the turns of the former winding (20) are each located on the negative side of the corresponding turn of the latter winding (21) in the wire-start region (alpha) and are wound around the winding-core section (14) so as to sandwich the turns of the latter winding (21) in the wire-end region (beta), whereas the turns of the latter winding (21) are each located on the positive side of the corresponding turn of the former winding (20) in the wire-end region (beta) and are wound around the winding-core section (14) so as to sandwich the turns of the former winding (20) in the wire-start region (alpha). The number of turns of the former winding (20) and the number of turns of the latter winding (21) are equal, as are the number of turns of the former winding (20) that are wound so as to contact the winding-core section (14) and the number of turns of the latter winding (21) that are wound so as to contact the winding-core section (14).

The present invention relates to a choke with two coils and a core for interleaved applications in step-up or step-down circuits or power factor compensation circuits. The core comprises several core sections with several lateral legs and a middle leg, whereby the core is designed such, that a coupling factor k of the two coils is smaller than 3%-5%. Furthermore, the core is designed such, that the core section form two loops with the middle leg as a common section, whereby each of the two coils lies on different loops outside of the common section. The lateral legs have a cross section A1 and the middle leg for the common section has a cross section A2<2×A1.

A phased array antenna system on an aircraft that incorporates a choke plate that significantly attenuates sidelobes of the antenna beam pattern at elevation angles that would cause RF interference with ground-based terrestrial wireless networks. The choke plate includes a plurality of choke grooves that substantially circumscribe the antenna aperture. The choke plate has an upper surface that is positioned generally coplanar with the upper surface of the antenna aperture. The grooves of the choke plate may be filled with a dielectric material. The choke plate provides a smooth aerodynamic component that significantly attenuates beam scattering, and thus the radiation pattern sidelobes of the antenna at or below the horizon, when the aircraft is in flight.

In a winding-type common mode choke coil serving as an example of a coil part, troubles such as mode conversion characteristics becoming larger due to the effects of stray capacitance are eliminated. A 0.5 shift region A which shifts 0.5 turns between a first wire (43) of a first layer and a second wire (44) of a second layer, and a 1.5 shift region B which shifts 1.5 turns in the opposite direction are distributed on a winding coil section (45) along the axial direction. In the 0.5 shift region A, a diagonal capacity which is quantified as -1 or +1 is generated for each one turn, and in the 1.5 shift region B, a diagonal capacity which is quantified as +3 or -3 is generated for each one turn. Here, the sum of the number of turns of the second wire (44) positioned in the 0.5 shift region A is set to be at least two times and at most five times the sum of the number of turns of the second wire positioned in the 1.5 shift region B, thereby balancing the diagonal capacity over the entirety of the first and second wires to reduce the effects of stray capacitance.

A common mode choke coil includes a primary coil and a secondary coil, wherein the primary coil includes a first coil pattern and a second coil pattern connected in series to the first coil pattern, and the secondary coil includes a third coil pattern and a fourth coil pattern connected in series to the third coil pattern. The first and third coil patterns are concentrically wound, as parallel or substantially parallel lines, in loop shapes on one surface, and the second and fourth coil patterns are concentrically wound, as parallel or substantially parallel lines, in loop shapes on the one surface with being adjacent to the first and third coil patterns.

The invention is comprised of a coil group arranging a plurality of terminal-integrated type coils ( 1 ), ( 4 ) formed by bending a metal sheet in a preset development form and having a predetermined positional relationship, and a magnetic material ( 7 ) burying therein the coil group. For example, axes of the plurality of coils ( 1 ), ( 4 ) constituting the coil group, are arranged in parallel wherein the center point of at least one coil selected from the plurality of coils ( 1 ), ( 4 ) and the center point of a coil other than the selected coil are in an staggered arrangement. Due to this, an array type choke coil can be realized which is thin overall and operable with a large current in a high frequency band.

A primary coil is configured by series connection of a first coil element (L1a), a second coil element (L1b) and a fifth coil element (L1c), and a secondary coil is configured by series connection of a third coil element (L2a), a fourth coil element (L2b) and a sixth coil element (L2c). The coil elements (L1a, L2b, L1c) are disposed coaxially and the coil elements (L2a, L1b, L2c) are also disposed coaxially. The respective coil elements (L1a, L1b, L1c) of the primary coil and the respective coil elements (L2a, L2b, L2c) of the secondary coil are disposed adjacently in a layer direction of a base material layer, respectively. The coil elements (L1a, L1b, L1c, L2a, L2b, L2c) are connected in such a manner that a magnetic field in the same direction is generated in all of the coil elements (L1a, L1b, L1c, L2a, L2b, L2c) when common mode current flows.

A method of controlling a direct current (“DC”) chopper controller having a switch and a storage choke in which the choke has a current dependent on the switching of the switch on and off includes the following. A current variable derived from one of the time averaged value of the current of the choke and the peak value of the current of the choke is determined. A switching frequency for synchronizing the turning on and off the switch is calculated as a function of the current variable and on whether the current variable exceeds a current threshold. The switching frequency is determined to be a predetermined low frequency if the switching frequency is lower than the low frequency and is determined to be a predetermined high frequency if the switching frequency is greater than the high frequency. The switch is switched on and off in accordance with the switching frequency.

An extremely thin embedded antenna for an armor-carrying vehicle utilizes a dipole driven element to the inside of the armor plate and a parasitically-driven dipole element on top of the armor plate, with the parasitic element providing appropriate forward gain and antenna matching characteristics such that there need be no aperturing of the armor plate in order to feed the antenna. In one embodiment, the bowtie antenna elements are elongated, extended or expanded by outboard antenna sections which are spaced from the distal ends of the corresponding bowties, with a meanderline choke bridging the gap between a bowtie element and its extended portion.

A common mode choke coil has a plurality of metallic conducting wires buried into a sintered magnetic material such that the metallic conducting wires are proximate to each other and an electrode mounted on a surface of the sintered magnetic material so as to be connected to each end portion of each of the metallic conducting wires. The metallic conducting wires are integrally coated with a non-magnetic and electrically insulating material at a predetermined distance between each of the metallic conducting wires to thereby form coated conducting wires. The coated conducting wires buried into the sintered magnetic material are thus obtained.

An output choke for a D.C. arc welder comprising a high permeability core with an inductance controlling air gap defined by first and second pole pieces terminating in first and second surfaces facing each other and each having two spaced edges with an intermediate area, said surfaces converging from said intermediate area toward each of said edges to generate a specific cross sectional shape for said gap wherein said choke is large enough to carry at least about 100 amperes of weld current.

The objective is to construct a noise filter which suppresses common mode noise and normal mode noise and can transmit a signal and further to construct a PLC modem excellent in a noise suppression characteristic by using the noise filter. This PLC modem has a common mode choke coil 8 consisting of two coils 8b and 8c wound around a magnetic core 8a and a magnetic core 8a, and capacitors 9 and 10 connected serially to the respective coils 8b and 8c, respectively. Serial tuning circuits 11 and 12 consisting of the coils 8b and 8c and the capacitors 9 and 10 are tuned to a prescribed frequency, parallel tuning circuits 6 and 7 for tuning to the prescribed frequency are respectively provided with at least one of the preceding stage side and the subsequent stage of the serial tuning circuits 11 and 12, and the parallel tuning circuits 6 and 7 are connected between the two serial tuning circuits 11 and 12.

The invention belongs to the technical field of monitoring of high-speed rail electrical systems and discloses a method and a device for monitoring geomagnetically induced current of high-speed rails. A high-speed rail geomagnetic storm damage monitoring and recording device comprises a traction main transformer and an earth box with a traction backflow collection function, a three-phase power source is connected into a traction substation, a traction backflow wire running through an earth wire, a PW protection wire and a choke transformer midpoint lead connected with two rail bars are arranged in the earth box which is an independent box structure , and the earth box is connected with an earth electrode of the traction transformer. Since interference exists in GIC (geomagnetically induced current) sampling signals, local high-frequency noise interference can be effectively eliminated by adopting a wavelet analysis method for variable-size localization analysis of time domain and frequency domain windows. The device comprises a signal acquisition sensor, a synchronous signal acquisition card and an industrial control computer. The device with a threshold alarming function is capable of sending alarm signals when monitoring quantity exceeds a threshold, so that influences of geomagnetic storm on a railway system can be known timely and conveniently. By monitoring for a period of time, direct-current magnetic bias current of the traction transformer is recorded to provide data for analysis on safety operation of a high-speed rail tractive power supply system.

The invention discloses an AC / AC converter. A corresponding principle comprises: acquiring alternating current power Uin (AC) from power grid (L, N, grounding); sending to a high-frequency transformer T-2 after passing through an EMI filter which is formed by differential mode capacitors C1, C2, a common mode choke T-1 and common mode capacitors C3, C4; performing by turns high frequency conduction to primary switches S1, S2of the high-frequency transformer T-2. Then, a power frequency voltage added on primary windings N3, N4 of the high-frequency transformer T-2 is converted into a high frequency voltage so that secondary windings N5, N6 of the high-frequency transformer T-2 can get the corresponding high frequency voltage. Through correspondingly controlling the switches S3, S4 of the secondary windings, any alternating current voltage Uo (AC) which is common-frequency, same-phase or anti-phase with an input voltage can be acquired on an output terminal. Through carrying out filtering by using a low pass filter which is formed by a L1 and a C5, a distortion factor of the Uo (AC) can be reduced.

The invention discloses an output matching circuit structure of a radio frequency power amplifier and a design method thereof, comprising a power amplifier tube, a choke inductor, an output end capacitance of the power amplifier tube, a second harmonic network and a broadband matching network; the second harmonic network is Two-terminal network; the broadband matching network includes a band-pass matching network composed of inductors and capacitors, and a DC blocking capacitor; the invention also provides a circuit parameter design method for an output matching circuit structure of a radio frequency power amplifier. The invention utilizes the output capacitor of the power amplifier tube, the second harmonic network and the broadband matching network to realize impedance conversion, enhances the suppression effect on the second harmonic, and makes better use of the third harmonic; thus, the output voltage of the power amplifier is improved. The waveform is closer to a square wave, and the output current is closer to a half-wave, so the overlap between the voltage waveform and the current waveform is small, which greatly improves the overall efficiency and linearity of the power amplifier, and effectively reduces the harmonic distortion of the RF power amplifier output stage.

An electric circuit-use core which has low loss, is less susceptible to magnetic saturation, thus allows for size reduction and current increase, and has a wide operation range in high-frequency region, and a manufacturing method for the core are provided. The electric circuit-use core is a dust core formed by compression molding or injection molding with an iron-based amorphous material, a cobalt-based amorphous material, or a sendust material as a magnetic material, and is used as a transformer core, a choke core, or a core of a reactor. The electric circuit-use core includes cylindrical pillar portions and connection portions.

The invention discloses a circuit structure for common-mode inductors with damping resistors applied to energy feedback devices. The circuit consists of an energy feedback device circuit consisting of a filter reactor and a feedback device inverting bridge, a frequency converter circuit consisting of a motor and a frequency converter inverting bridge, a DC bus and a three-phase power network group, wherein common-mode inductors with damping resistors are connected in series between the three-phase power network and the feedback device circuit connected with the three-phase power network or between the feedback device circuit and the frequency converter circuit connected with the feedback device circuit. The common-mode inductors in the circuit structure can effectively suppress common-mode current and reduce EMI interference so as to allow the application range of feedback devices to be wider. Through common-mode chokes designed, the energy feedback devices applying the circuit structure can allow resonance frequency points of common-mode current of main loops to be far from power-tube switching frequency, and the additional damping resistors can greatly reduce the common-mode current near resonance points so as to reduce common-mode interference caused by the work of the feedback devices and allow the feedback devices to be wider in application range and higher in reliability.

A method for designing a microwave oven magnetron includes design for a permissible range of a length of a choke for suppression of a harmonic higher than the fourth harmonic. The inventive magnetron includes; a cathode with a filament; a cylindrical metal anode around the cathode; a vane fixed onto the inner side of the anode for providing a plurality of resonant cavities radially directed toward the cathode; an antenna feeder having an outer diameter PHI 1; upper and lower magnets fixed to upper and lower yokes; and upper and lower magnetic poles which provide paths of a magnetic circuit. An anode seal having an opening whose inner diameter PHI 4 serves as a magnetic circuit path and a supporter of a body. A metal choke (having an inner diameter PHI 2, an outer diameter PHI 3, and a length La) is installed fixed onto the inner side of the anode seal and surrounds the antenna feeder in order to suppress over a fourth higher harmonic generated through the anode seal. The following numerical expression is used in design of PHI 1- PHI 4: where La is from 3.0 to 4.2 mm and lambda is the wavelength of the harmonic to be suppressed.

A magnetic element for multi-phase is composed by burying a plurality of coils in a composite magnetic material such that a negative coupling of magnetic fluxes or a positive coupling of magnetic fluxes exists between at least two coils. This structure more miniaturizes inductors, or choke coils as the multi-phase magnetic element suitably used for application of a large current to many kinds of electronic equipment. Such multi-phase magnetic element has an excellent ripple current property.