A system and method for tuning a transformer is provided. A transformer fixture may connect a switching network to a plurality of inductors of a transformer. At least one computing device may calculate a target number of turns for a primary coil and a secondary coil of the transformer based on a frequency response of the transformer. The switching network may connect the inductors of the transformer together in a pattern that results in the primary coil and secondary coil having the target number of turns.

A coil component has a core part 10 composing a closed magnetic path through which a closed loop of a magnetic flux passes, the magnetic flux being generated by two coils 14A, 14B that are arranged in parallel, and generate a magnetic field, and the core part 10 has a pair of I-type base cores 11A, 11B facing each other, and a pair of coupling core parts 11C, 11D. The coupling core parts 11C, 11D are each formed by linearly aligning three unit coupling cores 12A to 12F, and each of these cores 12A to 12F is formed into a configuration in which a column-shaped projection is provided on a core body, and a two-stage gap including a small gap and a large gap is to be formed mutually in a space in the adjacent unit cores 11A, 11B, and 12A to 12F by the configuration.

A device for reducing a magnetic unidirectional flux component in the core of a transformer includes at least one compensation winding, which is magnetically coupled to the core of the transformer, at least one switching unit in series with the compensation winding to feed a current into the compensation winding, and at least one current-limiting reactor in series with the compensation winding, wherein two switching units are connected in parallel with each other per current-limiting reactor and the current-limiting reactor comprises two windings, which can be connected either in series or in parallel with each other, in order to reduce the number of current-limiting reactors in comparison with conventional cascaded circuits.

An impedance matching device comprising a variable reactor having a main winding and control winding, wherein a generated magnet field in the core is an AC magnetic field with a magnitude exceeding a value to settle a deviation between a control target value for impedance matching and a feedback value, by changing the magnitude of the generated magnetic field by changing a control current passing through the control winding, thereby controlling inductance of the variable rector to be a predetermined value to perform impedance matching, the response delay in the impedance matching is reduced by reducing a response delay in the inductance variation of the variable reactor.

A system and method for tuning a transformer is provided. A transformer fixture may connect a switching network to a plurality of inductors of a transformer. At least one computing device may calculate a target number of turns for a primary coil and a secondary coil of the transformer based on a frequency response of the transformer. The switching network may connect the inductors of the transformer together in a pattern that results in the primary coil and secondary coil having the target number of turns.

Unique systems, methods, techniques and apparatuses for a ZVT ZCT resonant converter with a variable resonant tank are disclosed. One exemplary embodiment is a system comprising a bidirectional resonant converter comprising an input/output terminal, a switching device coupled with the input/output terminal, a resonant circuit coupled with the switching device and including a variable inductor, an output/input terminal coupled with the resonant circuit, and a DC biasing circuit operatively coupled with the variable inductor. The variable inductor comprises a toroidal core, a first winding wound around the toroidal core and coupled with the switching device and the output/input terminal, a second core structured to overlap a portion of the toroidal core, and a second winding wound around the second core and coupled with the DC biasing circuit. The DC biasing circuit is controllable to vary the inductance of the variable inductor by saturating a portion of the toroidal core.

A system and method for tuning a transformer is provided. A transformer fixture may connect a switching network to a plurality of inductors of a transformer. At least one computing device may calculate a target number of turns for a primary coil and a secondary coil of the transformer based on a frequency response of the transformer. The switching network may connect the inductors of the transformer together in a pattern that results in the primary coil and secondary coil having the target number of turns.

Magnetic flux valves can be used in electromagnetic (EM) power converters to electronically control output signals of the EM power converters. An input signal is provided to an EM power converter that includes two or more core sections in which at least one core section includes a magnetic flux valve having an adjustable reluctance. The EM power converter has one or more primary windings and one or more secondary windings wound around one or more core sections. One or more control signals are provided to the one or more magnetic flux valves to control a reluctance or reluctances of the one or more magnetic flux valves, affecting magnetic coupling between the primary and secondary windings. An output signal is generated, in which the output signal is a function of the input signal and the one or more control signals.

Among other things, a distribution transformer and a technique for regulating voltage are provided for herein. The distribution transformer comprises at least three windings and at least two ferromagnetic cores. The distribution transformer may also comprise a power electronic AC-AC converter operable to maintain the input voltage and current of the distribution transformer substantially in phase and/or to reduce fluctuation in the output voltage of the distribution transformer in the event of an increase or decrease in the input voltage, for example.

Embodiments of a variable inductor and a communication device are generally described herein. The variable inductor may comprise a signal wire and a control wire to receive a direct current (DC) control current. The variable inductor may further comprise a magnetic material integrated with the signal wire and the control wire. When a DC control current applied to the control wires takes a first current value, an inductance between an input node and an output node on the signal wire may take a first inductance value. When the DC control current takes a second current value, the inductance between the input node and the output node may take a second inductance value.