A circuit arrangement, includes output terminals that provide an output current and input terminals that receive a source current and a source voltage from a DC current source. A maximum power point tracker is coupled between the input terminals and the output terminals and a bypass circuit is coupled between the input terminals and the output terminals. The bypass circuit is configured to enter a bypass state dependent on the output current and dependent on the source current. The source current flows through the bypass circuit in the bypass state.

An electronic device may include electrical components. Each component may be powered at a different respective voltage. Voltage converter circuitry may convert a power supply input voltage into a suitable voltage for powering a corresponding component. The converter may include permanent magnets that include hard ferromagnetic materials. An inductor may be formed adjacent to the permanent magnets and within the magnetic field. The magnetic field may contribute to the inductance of the inductor. The inductor may be coupled between power switching circuitry and an output path. The power switching circuitry may receive the input voltage and may apply a duty cycle to the input voltage to generate an intermediate signal. The inductor may generate an output voltage having a different magnitude than the input voltage based on the intermediate signal. The inductor may provide the output voltage to the electrical component over the output path for powering the electrical component.

An electronic device may include electrical components. Each component may be powered at a different respective voltage. Voltage converter circuitry may convert a power supply input voltage into a suitable voltage for powering a corresponding component. The converter may include permanent magnets that include hard ferromagnetic materials. An inductor may be formed adjacent to the permanent magnets and within the magnetic field. The magnetic field may contribute to the inductance of the inductor. The inductor may be coupled between power switching circuitry and an output path. The power switching circuitry may receive the input voltage and may apply a duty cycle to the input voltage to generate an intermediate signal. The inductor may generate an output voltage having a different magnitude than the input voltage based on the intermediate signal. The inductor may provide the output voltage to the electrical component over the output path for powering the electrical component.

Power supply equipment includes an adapter which converts power from a power source to DC power for powering an electronic device. The power supply equipment includes circuitry which produces a data signal for use by the electronic device to control power drawn by the electronic device. A cable, extends from the adapter. The power supply equipment further includes a tip which has an input side and an output side. The input side of the tip is detachable mateable to the cable. The output side of the tip is detachably mateable to the electronic device. The tip output side has a shape and size dependent on the shape and size of a power input opening of the electronic device. The tip provides the data signal, as well as the DC power, to the electronic device. Different tips may be used to provide appropriate data signals to different electronic devices.

An electric transformer with a resonant primary and an inductive secondary includes a magnetic core, a primary winding having a first polarity and a secondary winding comprising a bifilar winding coupled in parallel to the primary winding and having an opposite polarity to the first polarity, the bifilar winding comprising a first winding and a second winding interconnected in series at a central derivation point, to which a first end of the capacitor is connected, the second end of the capacitor being connected to the input of the primary winding, wherein the first winding and the second winding each comprises a number of turns that corresponds to 40% of the number of turns of the primary winding; and wherein the bifilar winding is arranged in the same leg of the magnetic core of the primary winding. And a method for manufacturing the electric transformer.