79 results about "Magnetic amplifier" patented technology

Systems and methods for wireless power transfer are disclosed. Primary windings generate magnetic fields which are inductively coupled to secondary windings to transfer power in a wireless manner. One embodiment includes a plurality of tiles of magnetic cores and windings for the primary windings. The tiles can be arranged in a magnetic segment with windings of tiles being orthogonal with respect to windings of adjacent tiles. For example, a winding of a first tile can be horizontal, and windings of adjacent tiles can be vertical. One embodiment further groups these magnetic segments into larger entities, wherein each magnetic segment can be independently activated. One embodiment includes a magnetic amplifier or an electronic device for secondary side control of power. This permits multiple devices to be powered or charged to be able to regulate power or charging independently from one another.

Techniques for improved semiconductor device performance are provided. In one aspect, a semiconductor device is provided. The device comprises at least one free magnetic layer, and a magnetic amplifier interacting with the free magnetic layer comprising two or more magnetic layers with at least one nonmagnetic layer therebetween. The nonmagnetic layer may be configured to provide parallel exchange coupling J of the magnetic layers in a range of $0<J<\frac{4\pi t^2{M}_S^2{n}_y}{b},$

the magnetic layers having a long axis and a short axis, wherein t is a thickness of each magnetic layer, M_s is magnetization, n_y is a demagnetizing factor defined along the short axis of the magnetic layers and b is a diameter along a short axis of the magnetic layers. A method for switching a semiconductor device having at least one free magnetic layer is also provided.

A magnetic amplifier includes a saturable core having a plurality of legs. Control windings wound around separate legs are spaced apart from each other and connected in series in an anti-symmetric relation. The control windings are configured in such a way that a biasing magnetic flux arising from a control current flowing through one of the plurality of control windings is substantially equal to the biasing magnetic flux flowing into a second of the plurality of control windings. The flow of the control current through each of the plurality of control windings changes the reactance of the saturable core reactor by driving those portions of the saturable core that convey the biasing magnetic flux in the saturable core into saturation. The phasing of the control winding limits a voltage induced in the plurality of control windings caused by a magnetic flux passing around a portion of the saturable core.

A magnetic core for use in a saturable reactor made of an Fe-based soft-magnetic alloy comprising as essential alloying elements Fe, Cu and M, wherein M is at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti and Mo, and having an alloy structure at least 50% in area ratio of which being fine crystalline particles having an average particle size of 100 nm or less. The magnetic core has control magnetizing properties of a residual operating magnetic flux density DELTABb of 0.12 T or less, a total control operating magnetic flux density DELTABr of 2.0 T or more, and a total control gain Gr of 0.10-0.20 T/(A/m) calculated by the equation: Gr=0.8x(DELTABr-DELTABb)/Hr, wherein Hr is a total control magnetizing force defined as a control magnetizing force corresponding to 0.8x(DELTABr-DELTABb)+DELTABb.

The invention relates to the technology of power transformer, pulse transformer, magnetic amplifier and converter, in particular to a processing method for silicon steel ribbon iron core of direct current electric transmission and transformation radio-frequency reactor. According to the technical scheme provided by the invention, the processing method for the silicon steel ribbon iron core of direct current electric transmission and transformation radio-frequency reactor includes the following steps: a, winding, namely the silicon steel ribbon is wound into an iron core; b, heat treatment, namely the iron core primary product is annealed under vacuum; c, dipping paint, namely vacuum dipping paint is carried out on the iron core semifinished product; d, cutting, namely the iron core semifinished product after dipping paint is loaded into a cutting clamp of a cutting machine in a lying way, the cutting machine is started to begin cutting with the cutting speed of 200-300 r/min. The invention can improve the quality of product.

A DC-DC converter of multi-output type is provided wherein first and second MOS-FETs 1 and 2 are alternately turned on and off to take a plurality of DC outputs out of a plurality of secondary windings 4b, 4c and 4d of a transformer 4 through related rectifying smoothers 12, 22 and 32. A first DC output from first secondary winding 4b is controlled by adjusting a duty ratio of first and second MOS-FETs 1 and 2. At least one magnetic amplifier 21, 31 is connected in series between each of second or more secondary windings 4c and 4d and related rectifying smoother 22 and 32 to adjust reset current to the magnetic amplifier 21, 31, thereby generating stabilized DC-outputs V_O2 and V_O3 from the second or more secondary windings 4c, 4d.

A LED current-controlling circuit includes a first magnetic amplifier, a first current detecting circuit, a first magnetic amplifier controller and a first diode. The first magnetic amplifier is connected to an input terminal of the LED current-controlling circuit and the first LED string. The first current detecting circuit is connected to the first LED string in series for detecting the first current flowing through the first LED string. The first magnetic amplifier controller is used for controlling on/off statuses of the first magnetic amplifier. The first diode is connected to an output terminal of the first magnetic amplifier, the first LED string and the first magnetic amplifier controller. The first magnetic amplifier controller controls on/off statuses of the first magnetic amplifier according to the magnitude of the first current, thereby maintaining the first current at a specified DC current level.

Systems, methods and articles for providing lighting or illumination systems having drive circuits that employ a magnetic amplifier (“mag-amp”) and one or more feedback circuits to form a power converter that powers solid-state light sources (e.g., LEDs). The magnetic amplifier includes one or more magnetic cores which provides a controllable reluctance for magnetic flux. The magnetic amplifier includes one or more power windings which receive energy from an alternating current (AC) supply (e.g., AC mains) and delivers rectified AC current as direct current (DC) to one or more solid-state light sources. The magnetic amplifier includes one or more control windings coupled to a DC control source. The drive circuit may have two or more rectifiers (e.g., solid-state rectifiers) to provide a direct current to drive the solid-state light sources and also to isolate the one or more control windings from interference from the magnetic flux of the one or more power windings.

The invention discloses a high-frequency isolation type inverter for preventing three-phase load unbalance. The high-frequency isolation type inverter comprises a direct current input circuit, a high-frequency inverter, a high-frequency isolation transformer with double secondary side windings, a magnetic amplifier rectifying circuit, a direct current filter, a three-phase bridge type inverter and an alternating current filter, wherein the direct current input circuit is connected with the high-frequency inverter; the inversion voltage is transformed through the high-frequency isolation transformer with double secondary side windings; the two voltage output ends subjected to voltage transformation are respectively connected with the input end of the magnetic amplifier rectifying circuit; the output end of each magnetic amplifier rectifying circuit is connected with the direct current filter; the direct current filter is connected with the three-phase bridge type inverter; the three-phase bridge type inverter is connected with the alternating current filter; capacitors of two direct current filters are connected with each other; and the joint of the two capacitors is connected with a point N of the alternating current filter.

A power circuit include a plurality of LED strings, each LED string having multiple LEDs connected in series. A plurality of magnetic amplifiers, reset current sources, and a control circuit are used to drive each LED string with equal current and to independently regulate the amount of voltage supplied to each LED to maximize efficiency. One magnetic amplifier, one reset current source, and one current sink are dedicated to each LED string. The control circuit measures the voltage drop across each LED string and determines an amount of reset control current in response to the measured voltage drop. The reset control current is supplied by the reset current source to the magnetic amplifier dedicated to the regulated LED string. The amount of reset control current supplied to the magnetic amplifier dictates the amount of voltage supplied to the LED string.

An auxiliary output voltage control realized by bidirectional magnetized magnetic amplifier is disclosed. Its power transformer is composed of a transformer whose secondary side has a primary output voltage circuit and at least one auxiliary output circuit connected with magnetic amplifier, a PMW controller for controlling a switch at primary side of transformer, and a magnetic amplifier has two magnetizing windings for providing positive and negative magnetizing current.

The invention provides a transformer for improving the precision of output voltage. The transformer comprises a magnetic core and a framework matched with the magnetic core. The magnetic core comprises a plurality of side columns and a central column. The side columns are respectively arranged around the central column. The sectional areas of the side columns are respectively equal and the sum of the sectional areas is equal to the sectional area of the central column, and the sectional area of the connecting part between each side column and the central column is equal to that of each side column. The central column is provided with a primary winding and a secondary integral multiple winding. The side columns are respectively provided with a secondary winding with less than one coil and the secondary winding with less than one coil is evenly distributed on the side columns according to output current. Without the addition of extra linear voltage stabilizing circuits or magnetic amplifiers, the transformer can realize low-voltage and high-current multiplexed output and improves the precision of the output voltage thereof. The transformer is strong in reliability without the increase of volume and consumption.

A current control circuit that employs a magnetic amplifier and an active feedback circuit. The feedback circuit establishes the effective operating current of the amplifier at a fixed point. The magnetic amplifier includes a pair of oppositely wound gate windings, a bias winding and a control winding. The gate windings are driven by an oscillator driver that generates a gate winding current and a gate winding voltage. A reference voltage and the gate winding voltage are applied to a feedback amplifier and the feedback circuit. When the gate winding voltage becomes equal to the reference voltage, the feedback circuit is stable and the gate winding current is set to a desired zero current operating point.

An apparatus and method for use with a railroad dragging equipment detecting (DED) system that detects objects hanging from and dragged beneath a train as the train travels along rails of a railroad track. A generator supplies a first signal and is coupled to a magnetic amplifier coil to form a magnetically variable impedance circuit. The magnetic amplifier coil is responsive to the first signal to create a circuit impedance in series with a detection circuit. A magnet is mechanically connected to the cam/follower system and is positioned near the magnetic amplifier core for varying a circuit impedance of the detection circuit. A detection circuit generates a second signal as a function of variations in circuit impedance. A controller is responsive to the second signal for activating an alarm when the magnet moves relative to the magnetic amplifier coil.

This invention relates to a controllable inductor of an AC excitation amplifier and its usage characterizing in winding two windings on one iron-core post separately, one winding is a master one, the other is a control one, a commutating circuit is cut-in to both ends of the control winding, the output of the commutating circuit is parallel to a switch controlled by PWM. Said controlled inductor is especially suitable for high strength gas discharge lamp light adjusting energy saving circuit.

The present invention discloses a forward converter with secondary side post-regulation and zero voltage switching, where the primary side power loop may adopt a single or a dual transistor structure, driven by a primary side driving circuit with a constant duty ratio so that the voltage waveform across the secondary side power winding has a constant pulse width; the secondary side power loop uses a controllable switch, a magnetic amplifier (MA) or an N channel metal oxide semiconductor field transistor (NMOS), to blank the leading edge of the voltage waveform across the secondary side power winding, regulate the output voltage, and achieve zero voltage switching of primary side switch transistors.

The invention belongs to the technical field of power measurement and particularly discloses a direct-current-free magnetized bidirectional magnetic amplifier for direct-current large current detection. The magnetic amplifier can be used for measuring bidirectional direct current by using two iron cores only. An excitation signal of the magnetic amplifier is provided by an excitation transformer and a switch circuit, and an excitation current flowing through a winding of the excitation transformer is an alternating current, so that the direct-current magnetizing phenomenon is inexistent in the excitation transformer, thereby improving the efficiency of the excitation transformer and reducing the volume. A synchronous control voltage of the switch circuit is directly obtained from a secondary winding of the excitation transformer. The magnetic amplifier can serve as a current sensor and is applied to a zero-magnetic-flux direct-current large current transformer and a direct-current large current comparator.

The invention discloses a pulse drive transformer assembly for a self-excited switching power supply converter. The pulse drive transformer assembly (3) provides a drive signal for a power electronic switch assembly (Sk) in the self-excited switching power supply converter. By adopting a magnetic amplifier technology or a quadrature transformer technology, the power electronic switch assembly (Sk) driven by the pulse drive transformer assembly can normally work under an extremely-high amplitude direct current pulse power supply, so that the self-excited switching power supply converter finishes the filtering of a power supply alternating current input side of a commercial power grid without an electrolytic capacitor and generally meets the requirement without a power factor compensation (PFC). With the magnetic coupling current negative feedback action, the performance of the power electronic switch assembly (Sk) driven by the pulse drive transformer assembly is remarkably improved and the reliability of the complete machine can be improved. The invention has the advantages of low cost and high reliability and especially has remarkable benefits to energy-saving lamps and electronic ballasts.

This invention relates to a magnetic amplifier subsidiary output circuit for an isolation switch power supply including a subsidiary output winding, a magnetic amplifier, a commutation diode, a continuous current diode, a filter inductor, a filter condenser and a feedback control loop, among which, a rectifier is connected with both ends of the said continuous current diode in parallel, its gate drive circuit includes a first and a second triodes on-off alternatively, a current mutual-inductor first winding is serial on the said magnetic amplifier branch and its secondary winding is serial in the base emitting loop of the first triode, which detects the current signals of on-or-off of the magnetic amplifier to realize the synchronous on-or-off of a synchronous commutation tube by connecting a current mutual-inductor in a magnetic amplifier.

A high temperature magnetic amplifier, which utilizes the nonlinear properties of square loop magnetic cores to achieve very large amounts of both voltage and power amplification. By combining square loop, grain-oriented magnetic materials with high temperatures along with high temperature packaging approaches, high temperature long lifetime components can be produced. The high temperature magnetic amplifier is used as a building block to develop high temperature versions of operational amplifiers, comparators, voltage regulators, timers, counters, modulators, motor starters, servo systems, converters, inverters, power switches and many other devices.