Provided are circuits and methods for a power converter that converts AC input power into DC output power using a first output circuit that provides a first output comprising a DC voltage with a first AC voltage ripple and a second output circuit including a floating capacitor and one or more power switching device, and provides a second output comprising a second AC voltage ripple, wherein the first output and the second output are connected together in series, such that the first AC voltage ripple is substantially cancelled and substantially ripple-free DC output power is provided. Embodiments significantly reduce the total output capacitance requirement without sacrificing power factor, thus avoiding the need for electrolytic capacitors and enabling the use of long-life film capacitors. The circuits and methods are particularly suitable for use in applications where ripple-free high power and high reliability are required, such as in high power LED lighting.

Provided are circuits and methods for a power converter that converts AC input power into DC output power using a first output circuit that provides a first output comprising a DC voltage with a first AC voltage ripple and a second output circuit including a floating capacitor and one or more power switching device, and provides a second output comprising a second AC voltage ripple, wherein the first output and the second output are connected together in series, such that the first AC voltage ripple is substantially cancelled and substantially ripple-free DC output power is provided. Embodiments significantly reduce the total output capacitance requirement without sacrificing power factor, thus avoiding the need for electrolytic capacitors and enabling the use of long-life film capacitors. The circuits and methods are particularly suitable for use in applications where ripple-free high power and high reliability are required, such as in high power LED lighting.

A power supply apparatus requests the transmission of a requested PDO. A power receiving apparatus transmits the requested PDO in response to the request. The power supply apparatus modifies a first PDO list based on the requested PDO when it is possible to do so. The first PDO list is modified when the requested voltage is not defined in the first PDO list in a case in which a power supply circuit of the power supply apparatus is capable of supplying the request voltage indicated by the requested PDO. Subsequently, negotiation is performed based on the first PDO list thus modified.

The present disclosure provides a charging method and a charging system. The charging system includes a charging adapter and a mobile terminal, the charging adapter includes a second controller and an adjusting circuit, and the mobile terminal includes a cell detection circuit and a cell. The cell detection circuit acquires a voltage value of the cell, and sends the voltage value of the cell to the second controller, the second controller searches a threshold range table for a current adjusting instruction matched with a threshold range containing the voltage value of the cell, and sends the current adjusting instruction to the adjusting circuit, and the adjusting circuit performs a current adjustment according to the current adjusting instruction and outputs a power signal after the current adjustment, in which the threshold range table records threshold ranges and current adjusting instructions having a one-to-one mapping relation with threshold ranges.

A passively powered image capture device includes a remote execution unit structured to receive commands from a base station and an imaging device coupled to the remote execution unit. The imaging device is structured to be controlled by the remote execution unit based on the commands received by the remote execution unit. The passively powered image capture device also includes an antenna and energy harvesting circuitry coupled to the antenna, the remote execution unit and the imaging device. The energy harvesting circuitry is structured to convert RF energy received by the antenna to DC energy for powering the remote execution unit and the imaging device.

An apparatus for converting power includes at least one impedance matching network which receives an electrical signal. The apparatus includes at least one AC to DC converter in communication with the impedance matching network. Also disclosed is a method for powering a load and an apparatus for converting power and additional embodiments of an apparatus for converting power.

An apparatus for converting power includes at least one impedance matching network which receives an electrical signal. The apparatus includes at least one AC to DC converter in communication with the impedance matching network. Also disclosed is a method for powering a load and an apparatus for converting power and additional embodiments of an apparatus for converting power.

A method of operating a controller for a power converter having a plurality of switches couplable to respective electrical devices is disclosed, in which the controller includes a switch activating unit, a frequency varying unit, a comparator and a selector. The method comprises comparing respective electrical parameters of the electrical devices with respective reference electrical parameters by the comparator to obtain associated results; and based on the results, selecting by the selector either no switches or at least one switch to be activated to enable at least two electrical devices to be electrically connected. The activation is performed on receipt of a signal pulse, and if no switches are selected, the signal pulse is skipped by the switch activating unit to reduce power consumption of the controller, and based on the results, a frequency of the signal pulse is varied by the frequency varying unit to further reduce power consumption of the controller. A controller is also disclosed.

A voltage error signal V.sub.ERR is provided to a PWM controller of a voltage regular and used to produce a PWM signal that drives a power stage of the regulator. When operating in an adaptor current limit regulation mode, an adaptor current sense voltage V.sub.ACS, indicative of an adapter current I.sub.A, is compared to an adapter current reference voltage V.sub.AC.sub._.sub.REF to produce an adapter current error signal V.sub.AC.sub._.sub.ERR. A compensator receives the adapter current error signal V.sub.AC.sub._.sub.ERR and outputs a compensated adapter current error signal. The adaptor current sense voltage V.sub.ACS, or a high pass filtered version thereof, is subtracted from the compensated adapter current error signal to produce the voltage error signal V.sub.ERR provided to the PWM controller. Alternatively, an input voltage V.sub.IN, or a high pass filtered version thereof, is added to the compensated adapter current error signal to produce the voltage error signal V.sub.ERR.

A voltage error signal V.sub.ERR is provided to a PWM controller of a voltage regular and used to produce a PWM signal that drives a power stage of the regulator. When operating in an adaptor current limit regulation mode, an adaptor current sense voltage V.sub.ACS, indicative of an adapter current I.sub.A, is compared to an adapter current reference voltage V.sub.AC.sub._.sub.REF to produce an adapter current error signal V.sub.AC.sub._.sub.ERR. A compensator receives the adapter current error signal V.sub.AC.sub._.sub.ERR and outputs a compensated adapter current error signal. The adaptor current sense voltage V.sub.ACS, or a high pass filtered version thereof, is subtracted from the compensated adapter current error signal to produce the voltage error signal V.sub.ERR provided to the PWM controller. Alternatively, an input voltage V.sub.IN, or a high pass filtered version thereof, is added to the compensated adapter current error signal to produce the voltage error signal V.sub.ERR.