Abstract: A structure comprises a plurality of first turns of a coil and a plurality of second turns of the coil having a similar shape as the plurality of first turns of the coil, wherein the plurality of first turns of the coil and the plurality of second turns of the coil have a similar center position and a current flowing through the plurality of first turns of the coil and a current flowing through the plurality of second turns of the coil are in opposite directions.

Abstract: A multilevel LLC resonant converter comprises a first capacitor and a second capacitor connected in series providing a mid-voltage point of an input dc power source, a resonant tank connected in series with a primary side of a transformer, a first transistor and a second transistor connected in series, wherein a common node of the first transistor and the second transistor is connected to the mid-voltage point through a first isolation switch and a third transistor and a fourth transistor connected in series, wherein a common node of the third transistor and the fourth transistor is connected to the mid-voltage point through a second isolation switch.

Abstract: A power converter comprises a primary switch network coupled to a power source, wherein the primary switch network comprises a plurality of power switches, a controller configured to generate gate drive signals for the plurality of power switches, a secondary rectifier coupled to an output, a first transformer having a first winding coupled to the primary switch network, a second winding coupled to the secondary rectifier and a third winding coupled to the controller and a second transformer having a fourth winding coupled to the primary switch network, a fifth winding coupled to the secondary rectifier and a sixth winding coupled to the controller, wherein a voltage signal from the third winding and/or the sixth winding is processed to provide a feedback of a voltage at the output.

Abstract: A device comprises a switch network coupled to a power source, wherein the switch network comprises a plurality of power switches, a transmitter resonant tank coupled to the plurality of power switches, wherein the transmitter resonant tank comprises a primary resonant capacitor, a transmitter coil coupled to the transmitter resonant tank and a harmonic reduction apparatus coupled between the switch network and the transmitter coil, wherein the harmonic reduction apparatus is configured to attenuate at least one undesired frequency component.

Abstract: A system comprises a power amplifier configured to receive a frequency control signal, wherein the frequency control signal is generated based upon a system clock of a communication device and the frequency control signal is used to control a switching frequency of the power amplifier and a first resonant circuit coupled between the power amplifier and a first coil, wherein the first resonant circuit comprises a first variable capacitance network.

Abstract: A system comprises a primary switch network coupled to a power source, wherein the primary switch network comprises a plurality of power switches, a primary resonant tank coupled to the plurality of power switches, wherein a resonant capacitor of the primary resonant tank is formed by a first variable capacitance network, and wherein the first variable capacitance network is modulated to improve soft switching of the plurality of power switches through reducing a voltage level and a current level of a switch at a turn-on instant and a primary coil coupled to the primary resonant tank.

Abstract: An embodiment apparatus comprises a secondary synchronous rectifier and a secondary gate drive controller coupled to a transformer winding. The secondary gate drive controller is configured to generate a forward gate drive signal for the forward switch and generate a freewheeling gate drive signal for the freewheeling switch, wherein the secondary gate drive controller generates a dead time between the forward gate drive signal and the freewheeling gate drive signal.

Abstract: A device has a plurality of power converter groups and a control system. A power converter group has a group of power converters and is coupled between an input voltage source and a group of windings of a motor generator. The control system is configured to control currents of the windings such that the number of poles of and the number of phases in a pair of poles of the motor/generator are dynamically adjusted, and the number of poles and the strength of a magnetic field of the motor generator are controlled to reduce a power loss. The motor/generator has an air gap and a stator with a plurality of slots, where the windings are installed in. The windings are configured such that the number of poles and the number of phases in a pair of poles of the motor/generator can be dynamically adjusted.

Abstract: A method includes coupling a primary side circuit of a resonant power system to a secondary side circuit, wherein the primary side circuit comprises a first resonant tank comprising a first variable capacitance network having a first resonant frequency and the secondary side circuit comprises a second resonant tank having a second resonant frequency and modulating a capacitance of the first variable capacitance network to adjust an operation parameter of the resonant power system.

Abstract: An apparatus comprises a first capacitor and a second capacitor connected in series, a diode and the second capacitor connected in parallel, wherein a cathode of the diode is connected to a common node of the first capacitor and the second capacitor and a plurality of adjustable capacitance networks connected in parallel with the second capacitor.

Abstract: A device comprises a motor/generator having an air gap and a plurality of windings, a plurality of power converter groups, and a control system. The windings are so configured that the number of phases in a pair of poles and the number of poles of the motor/generator can be dynamically adjusted. The power converter group comprises a plurality of power converters which is coupled between an input voltage source and a plurality of windings for controlling currents in the windings. The control system is so configured such that the number of poles of the motor/generator and the number of phases in a pair of poles are dynamically adjusted, and a synchronous speed of a moving magnetic field generated by winding currents within first pair of poles is approximately equal to a synchronous speed of a second moving magnetic field generated by currents in the windings within second pair of poles.

Abstract: An apparatus comprises a sense transistor having a gate and a source directly connected to a gate and a source of a power transistor of a resonant converter respectively, wherein the resonant converter comprises a primary side and a secondary side magnetically coupled to the primary side, a current sense and amplification circuit comprising an amplifier having inputs connected to a drain of the sense transistor and a drain of the power transistor respectively, an analog-to-digital converter connected to an output of the current sense and amplification circuit and a digital controller connected to an output of the analog-to-digital converter, wherein the digital controller is configured to modulate a variable capacitance network of the resonant converter based upon a current flowing through the sense transistor.

Abstract: A structure comprises a plurality of first turns of a coil and a plurality of second turns of the coil having a similar shape as the plurality of first turns of the coil, wherein the plurality of first turns of the coil and the plurality of second turns of the coil have a similar center position and a current flowing through the plurality of first turns of the coil and a current flowing through the plurality of second turns of the coil are in opposite directions.

Abstract: A power converter comprises a switch network coupled to an input voltage, a power transformer having a primary winding and a secondary winding, wherein the primary winding is coupled to the switch network, and the secondary winding is coupled to a rectifier, wherein the rectifier is coupled to an output voltage, a primary resonant tank having a first resonant capacitor and a first resonant frequency, and coupled to the primary winding of the power transformer and the switch network, and a regulation circuit configured to control the output voltage of the power converter to be substantially proportional to the input voltage and the switch network to operate at a frequency substantially close to the first resonant frequency.

Abstract: An embodiment holdup time circuit of a bridgeless power factor correction circuit comprises a charge device connected between an output terminal of a bridgeless power factor correction circuit and an energy storage apparatus, a discharge device connected between the energy storage apparatus and an input of the bridgeless power factor correction circuit, the energy storage apparatus and the bridgeless power factor correction circuit comprising a first boost converter, a second boost converter, a first switch and a second switch, wherein the first switch is connected between the first boost converter and ground and the second switch is connected between the second boost converter and ground.

Abstract: A structure comprises a first portion of a winding having a first almost enclosed shape, a second portion of the winding having a second almost enclosed shape and a connection element between the first portion and the second portion, wherein the first portion and the second portion are arranged in a symmetrical manner and the first portion, the second portion and the connection element form a first air core inductor.

Abstract: An embodiment power converter package comprises a semiconductor die, an output inductor, a plurality of input capacitors and output capacitors. The semiconductor die, the output inductor and the plurality of capacitors are mounted on a lead frame and connected one to another through various pads on the lead frame. The semiconductor die comprises a high side switch, a low side switch and a driver. The power converter package is electrically coupled to an external pulse width modulation controller through a variety of input and output pads.

Abstract: A power system comprising a non-isolated voltage regulator configured to couple to an input voltage and produce an output voltage, wherein the non-isolated voltage regulator is in a power distribution system and configured to boost the input voltage when the input voltage is less than a minimum output voltage, to reduce the input voltage when the input voltage is greater than a maximum output voltage, and to pass-through the input voltage when the input voltage is greater than or equal to the minimum output voltage and less than or equal to the maximum output voltage.

Abstract: An embodiment holdup time circuit of a bridgeless power factor correction circuit comprises a charge device, an energy storage apparatus and a discharge device. The charge device comprises a first terminal coupled to a bridgeless power factor correction circuit and a second terminal coupled to the energy storage apparatus. The discharge device comprises a first terminal coupled to the energy storage apparatus and a second terminal coupled to the bridgeless power factor correction circuit.

Abstract: A multilevel LLC resonant converter comprises a first capacitor and a second capacitor connected in series providing a mid-voltage point of an input dc power source, a resonant tank connected in series with a primary side of a transformer, a first transistor and a second transistor connected in series, wherein a common node of the first transistor and the second transistor is connected to the mid-voltage point through a first isolation switch and a third transistor and a fourth transistor connected in series, wherein a common node of the third transistor and the fourth transistor is connected to the mid-voltage point through a second isolation switch.