The present invention relates to resonant power converters and inverters comprising a self-oscillating feedback loop coupled from a switch output to a control input of a switching network comprising one or more semiconductor switches. The self-oscillating feedback loop sets a switching frequency of the power converter and comprises a first intrinsic switch capacitance coupled between a switch output and a control input of the switching network and a first inductor. The first inductor is coupled in-between a first bias voltage source and the control input of the switching network and has a substantially fixed inductance. The first bias voltage source is configured to generate an adjustable bias voltage applied to the first inductor. The output voltage of the power converter is controlled in a flexible and rapid manner by controlling the adjustable bias voltage.

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.

An apparatus may include a first device having a first metal structure, a first metal element, and a first transistor. The first metal structure may include first and second surfaces, that are flat and opposite facing. The first metal element may include first and second surfaces that are flat and opposite facing. The first transistor may include first and second terminals between which 1 amp or more of electrical current is transmitted when the first transistor is activated, wherein the first and second terminals may include first and second surfaces, respectively, that are substantially flat and opposite facing. The second surface of the first metal structure can be electrically and thermally connected to a bus bar. The first and second surfaces of the first and second terminals, respectively, may be sintered to the first and second surfaces, respectively, of the first metal structure and the first metal element, respectively.

A wireless charging control circuit includes at least one control sub-circuit. Each control sub-circuit is configured to, prior to turn-on of a target switching transistor based on a received PWM signal, send a pulse width adjustment instruction to a signal processor corresponding to the target switching transistor based on a voltage difference between a first terminal and a second terminal of the target switching transistor, to instruct the signal processor to adjust a pulse width of a next PWM signal input to the target switching transistor. In this way, the wireless charging control circuit is capable of adaptively regulating the pulse width of the PWM signal, which avoids excessively large or small dead times, such that electromagnetic interference is prevented and conversion efficiency of a charging circuit is improved.

An apparatus may include a first device having a first metal structure, a first metal element, and a first transistor. The first metal structure may include first and second surfaces, that are flat and opposite facing. The first metal element may include first and second surfaces that are flat and opposite facing. The first transistor may include first and second terminals between which 1 amp or more of electrical current is transmitted when the first transistor is activated, wherein the first and second terminals may include first and second surfaces, respectively, that are substantially flat and opposite facing. The second surface of the first metal structure can be electrically and thermally connected to a bus bar. The first and second surfaces of the first and second terminals, respectively, may be sintered to the first and second surfaces, respectively, of the first metal structure and the first metal element, respectively.