An apparatus including a board, an inductor that is provided on the board, a guard ring that includes a first guard ring part provided to be adjacent to a circumference of the inductor and a second guard ring part provided to be adjacent to an outer side of the first guard ring part, in which one end of the second guard ring part is connected to one end of the first guard ring part, and a first power supply that is connected to another end of the first guard ring part and another end of the second guard ring part.

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.

In the printed circuit board 100 in the power supply device, cover layers C1 and C2 are formed on a surface other than the connection areas 95A′ and 95B′ within a coil pattern EC, which corresponds to a surface-shaped exposure area exposed to the outside so that the size of the surface-shaped exposure area to which the conductive pattern E is exposed is adjusted, so that an effect, which restrains a conductor from being damaged, especially at a time of carrying the printed circuit board 100 while maintaining a heat radiating property of the conductor, is achieved.

Voltage controlled magnetic components are described. The magnetic components include a thin layer of ferromagnet adjacent to an oxide layer. The magnetic properties of the ferromagnet may be controlled in a reversible manner via application of an external electric field and voltage-induced reversible oxidation of the ferromagnet.

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.

Tunable electronic units and associated systems, as well as methods for tuning characteristic properties of soft electronic units (e.g., inductance, capacitance, and resistance) and fabricating soft tunable planar inductors, axial inductors, capacitors, and resistors, are provided. Disclosed systems and methods enable standardized tuning of different types of soft electronic units (e.g., including a soft inductor, capacitor, and resistor, etc.), and enable remote tuning while maintaining a tuned value without expending power. In certain embodiments, electrical properties of the soft electronic units are tuned using a mobile component (e.g., ferrofluid and iron powder) dragged with a permanent magnet inside a soft fluidic channel. This may be used for applications and devices which need to be soft and flexible, such as implantable electronics, wearable devices, and skin electronics.

Method for producing an integrated magnetic device with variable inductance, comprising: a) making of a piezoelectric element on a first substrate; b) making of a first electrically conductive element on a face of the piezoelectric element, and fastening of the ends of the piezoelectric element to a second substrate such that the piezoelectric element is arranged facing a cavity formed between the second substrate and the piezoelectric element, the first electrically conductive element being arranged in and/or against the second substrate or against the piezoelectric element; c) removing of the first substrate; d) making of a second electrically conductive element on another face of the piezoelectric element; and further comprising the making of an electrical and/or magnetic coupling of the first and second electrically conductive elements, and the making of a magnetic element arranged against and/or in the piezoelectric element and between the electrically conductive elements.

Method for producing an integrated magnetic device with variable inductance, comprising: a) making of a piezoelectric element on a first substrate; b) making of a first electrically conductive element on a face of the piezoelectric element, and fastening of the ends of the piezoelectric element to a second substrate such that the piezoelectric element is arranged facing a cavity formed between the second substrate and the piezoelectric element, the first electrically conductive element being arranged in and/or against the second substrate or against the piezoelectric element; c) removing of the first substrate; d) making of a second electrically conductive element on another face of the piezoelectric element; and further comprising the making of an electrical and/or magnetic coupling of the first and second electrically conductive elements, and the making of a magnetic element arranged against and/or in the piezoelectric element and between the electrically conductive elements.

In the reactor in which the wiring board with the main winding formed thereon and the wiring board with the control winding formed thereon are incorporated in layers into the planer core, the magnetic flux generated by the main winding and the magnetic flux generated by the control winding are brought into the following states in order to equalize the density of the magnetic flux generated by the control current. A main winding current of high-frequency current flowing through the main winding generates an AC magnetic fluxes, each of the fluxes having a magnetic field in a direction opposite to each other so as to cancel each other out, and a control current of direct current flowing through the control winding generates a DC magnetic flux with a uniform magnetic flux density around the pair of the inner legs of which AC magnetic fluxes are cancelled out each other.

In the reactor in which the wiring board with the main winding formed thereon and the wiring board with the control winding formed thereon are incorporated in layers into the planer core, the magnetic flux generated by the main winding and the magnetic flux generated by the control winding are brought into the following states in order to equalize the density of the magnetic flux generated by the control current. A main winding current of high-frequency current flowing through the main winding generates an AC magnetic fluxes, each of the fluxes having a magnetic field in a direction opposite to each other so as to cancel each other out, and a control current of direct current flowing through the control winding generates a DC magnetic flux with a uniform magnetic flux density around the pair of the inner legs of which AC magnetic fluxes are cancelled out each other.