A magnetic element includes a magnetic core and a winding. The magnetic core includes a first and second magnetic cover disposed oppositely, and at least one first magnetic column, at least one second magnetic column and at least one common magnetic column disposed between the first and second magnetic covers. The winding includes at least one first winding wound around at least one first magnetic column, and at least one second winding wound around at least one said second magnetic column. A first differential mode inductor is formed with the first winding, the first magnetic column, the first magnetic cover, the common magnetic column and the second magnetic cover. A power inductor or a power transformer is formed with the second winding, the second magnetic column, the first magnetic cover, the common magnetic column and the second magnetic cover.

The present invention relates to a submodule for a semiconductor transformer in single packaging with excellent performance of insulation and prevention against induction heating that is capable of preventing induction heating caused by a magnetic field generated from coils by being equipped with a shield with at least specified conductivity in the semiconductor transformer while improving insulation performance by securing separation distance between a high voltage unit and a low voltage unit in the semiconductor transformer. The submodule for the semiconductor transformer in single packaging with excellent performance of insulation and prevention against induction heating in accordance with the present invention comprises: a high voltage unit for converting high-voltage low-frequency AC power into high-voltage AC power; a transforming unit for converting the high-voltage AC power into low-voltage AC power; and a low voltage unit for converting the low-voltage AC power into low-voltage DC power.

An apparatus includes a primary transformer circuit including a plurality of primary coils. The apparatus further includes a delta secondary transformer circuit configured to magnetically couple to the primary transformer circuit. The delta secondary transformer circuit includes a first plurality of secondary coils, a first plurality of nodes coupled to the first plurality of secondary coils, and a second plurality of secondary coils configured to magnetically couple to the plurality of primary coils. Each coil of the second plurality of secondary coils is physically coupled to a respective node of the first plurality of nodes.

An equivalent circuit of a converter (4) is represented by a series connection between an equivalent capacitor (41) and an equivalent resistor (42), and the converter (4) includes a controller that adjusts a power factor of the input power by controlling a capacitive reactance (Xc) of the equivalent capacitor (41).

A power supplying apparatus includes a first piezoelectric transformer operated at a first operating frequency, a second piezoelectric transformer operated alternately with the first piezoelectric transformer and operated at a second operating frequency, wherein the second operating frequency is a multiple of the first operating frequency.

A power supply device includes a transformer including a primary winding, a secondary winding and an auxiliary winding, first, second and third circuits, and a switch. The first circuit in which a first capacitor and a first rectifier are connected in series is connected to the primary winding in parallel. The switch of which one end is connected to one end of the primary winding. The second circuit in which the auxiliary winding and a second rectifier are connected in serial is connected between a connecting point, to which the first capacitor and the first rectifier are connected, and the other end of the switch. The third circuit including a resistor and a third rectifier is connected to a gate of the switch. In the third circuit, a resistance value in a direction where a current flows into the gate of the switch is smaller than that in a direction where the current flows out of the gate.

Embodiments includes systems, methods, and apparatuses for determining a resonant frequency of an LLC converter via a primary side of the LLC converter. In one embodiment, a circuit comprises an LLC converter and a resonant frequency determination unit, the resonant frequency determination unit configured to monitor electrical current on the primary side of the LLC converter, isolate a portion of the electrical current, determine, based on the portion of the electrical current, a crossing point, and determine, based on the crossing point, a resonant frequency of the LLC converter.

An equivalent circuit of a converter (4) is represented by a series connection between an equivalent capacitor (41) and an equivalent resistor (42), and the converter (4) includes a controller that adjusts a power factor of the input power by controlling a capacitive reactance (Xc) of the equivalent capacitor (41).

The present invention relates to the technical field of radio frequency identification, in particular to a rectifier and limiter circuit having a plurality of time constants and a passive radio frequency tag containing this rectifier and limiter circuit. By applying analog control signals with different time constants to control terminals of two discharge paths of the rectifier and limiter circuit, respectively, i.e., adjusting the voltage amplitude at different switching speeds, switching the two discharge paths from a completely open state to a completely closed state is realized. Discharging is performed properly according to the amount of charge at antenna terminals and the level of energy of the tag, thus to improve the demodulation capacity of the tag and increase the read-write distance of the tag.

The present invention is directed to a piezoelectric transformer based power converter that exhibits efficient operating point tracking ability while providing output regulation by means of simultaneous two-parameter control of the converter power stage. A regulation control stage provides the power stage a regulation control signal indicative of the difference between the measured output parameter and a set-point reference, therefore continuously controlling the gain of the converter to result in a stabilized, regulated output. Additionally, a frequency control stage simultaneously provides the power stage with a frequency control signal correlative to the difference between the current and desired operating points of the piezoelectric transformer. The power stage then translates the frequency control signal into an adjustment to the operational frequency of the input signal to the piezoelectric transformer, as to continuously drive the operating point to the desired position.