Apparatuses including multiple selectable circuit elements are described. In an example, an apparatus may include a power supply configured to output a voltage. The apparatus may further include a controller connected to the power supply and a transmission unit connected to the controller. The transmission unit may be configured to output power. The transmission unit may include comprising an inverter connected to the power supply. The inverter may include a high-side switching element. The transmission unit may further include a circuit element a circuit connected to the power supply. The circuit may be configured to select the circuit element. The circuit may include a switch connected between the inverter and the circuit element. The switch and the high-side switching element may be configured to be driven by the voltage outputted by power supply. The controller may be configured to control the power being outputted by the transmission unit.

An inverter. The inverter includes a first and second transistors, which are a high-side transistor and a low-side transistor of the inverter, and control electronics configured to trigger a first switching operation, in which the first transistor is switched on, wherein the second transistor is in a switched-off state, wherein a parasitic capacitance of the first transistor is discharged during the first switching operation, to trigger a second switching operation, in which the first transistor is switched off or switched on again, wherein the second transistor simultaneously remains in the switched-off state, wherein the parasitic capacitance of the first transistor is already discharged in the second switching operation, to record a time difference which describes a difference between a duration of the first switching operation and a duration of the second switching operation, and to determine a characteristic operating parameter of the first transistor based on the time difference.

A non-contact power supply device includes an inverter to convert power supplied from a power supply into a predetermined AC power, feeders provided on a track rail to transmit the AC power to a ceiling conveyor, a filter circuit including a reactor and a capacitor, and a controller configured or programmed to perform power control of the AC power that is to be supplied to the feeders. The controller is configured or programmed to obtain a current value output from the inverter while changing a switching frequency of switches of the inverter in a state in which a current having a predetermined value flows through the feeders, and to set and output a reactor value of the reactor and a capacitance value of the capacitor based on the switching frequency at which the current value is minimum.

Systems and apparatuses are disclosed that include a distributed power system configured to provide power to a number of loads. The system includes power converters configured to receive DC power from a common power source, each of the plurality of power converters configured to provide DC power to a corresponding load from. Each of the power converters is positioned proximal to the corresponding load that it powers.

A voltage converter, including an input adapted to couple to a voltage source and a transformer including a primary coil and a secondary coil. Primary side circuitry, including a first switching circuit, is coupled to the primary coil. A second switching circuit is coupled between a first terminal and a second terminal of the secondary coil, and configured to selectively close to short circuit the first terminal to the second terminal.

A resonant converter and a manufacturing method of a transformer thereof are provided. The resonant converter includes a full bridge circuit, an element, a first branch circuit, a second branch circuit and a secondary winding. The full bridge circuit includes a first node and a second node. The element includes an inductor or a capacitor. The first branch circuit includes a first primary winding. The second branch circuit includes a second primary winding, and the first and second primary windings have the same turn number. The transformer is constructed by the first and second primary windings and the secondary winding. The first branch circuit, the element and the second branch circuit are sequentially coupled in series between the first and second nodes. The first branch circuit and the second branch circuit are symmetrically located with respect to the element. The first and second branch circuits have the same impedance.

A switched capacitor modulator (SCM) includes a RF power amplifier. The RF power amplifier receives a rectified voltage and a RF drive signal and modulates an input signal in accordance with the rectified voltage to generate a RF output signal to an output terminal. A reactance in parallel with the output terminal is configured to vary in response to a control signal to vary an equivalent reactance in parallel with the output terminal. A controller generates the control signal and a commanded phase. The commanded phase controls the RF drive signal. The reactance is at least one of a capacitance or an inductance, and the capacitance or the inductance varies in accordance with the control signal.

An induction heating apparatus according to an embodiment of the present specification comprises a main control circuit for adjusting the capacitance of the variable capacitor circuit according to a driving mode of the inverter circuit determined on the basis of a load resistance value of a container placed on the working coil and adjusting the magnitude of the direct current link voltage according to a final voltage value calculated on the basis of an equivalent resistance value of the container and the working coil and a required power value for the working coil.

An interleaved LLC converter arrangement includes two or more LLC converters for transferring power from an input side to an output side, wherein the two or more LLC converters include a first LLC converter and a second LLC converter connected in parallel on the input side and on the output side and wherein each LLC converter includes a bridge inverter at the input side. For balancing the power transfer among the LLC converters if for example the second LLC converter transfers more power from the input side to the output side than the first LLC converter, each leg of the bridge of the bridge inverter of the first LLC converter is operated with a duty cycle of 0.5 and at least one leg of the bridge of the bridge inverter of the second LLC converter is operated with a duty cycle different from 0.5.

A quasi-resonant auto-tuning controller includes a zero-voltage crossing detection circuit and a valley tuning finite-state machine having a look-up table. The zero-voltage crossing detection circuit receives a reference voltage and receives an auxiliary signal from an auxiliary winding. The zero-voltage crossing detection circuit produces a comparison signal having pulses when the auxiliary signal is less than the reference voltage. The valley tuning finite-state machine produces a divided pulse width based on the comparison signal, stores the divided pulse width of each pulse in the look-up table, determines, from the comparison signal, that the auxiliary signal is less than the reference voltage, waits a time period corresponding to the divided pulse width stored in the look-up table if the auxiliary signal is less than the reference voltage, and produces a valley point signal after waiting the time period.