A power supply circuit of a step-down type, configured to generate an output voltage at a predetermined level from an alternating current (AC) voltage. The power supply circuit includes a rectifier circuit configured to rectify the AC voltage, a first line coupled to the rectifier circuit, a second line on a ground side, a switch coupled between the first line and the second line, and a control circuit configured to control the switch to bring a level of the output voltage to the predetermined level. The power supply circuit is free of an inductor interposed between the first line and the rectifier circuit.

A circuit and methods describing a complementary metal-oxide semiconductor (CMOS) rectifier for use in radio frequency (RF) energy harvesting with body biasing by the RF input to control the threshold voltage of each transistor. The CMOS rectifier includes an energy harvesting antenna, and multiple rectifier stages. The antenna receives electromagnetic radiation from the environment and generates a DC current. The oscillating input current is an RF.sup.+ positive current during a first half cycle and is an RF.sup.? negative current during a second half cycle. A first rectifier stage includes a first capacitor connected to the RF.sup.+ positive current, a second capacitor connected to the RF.sup.? negative current and a cross coupled CMOS circuit connected to the antenna.

A circuit and methods describing a complementary metal-oxide semiconductor (CMOS) rectifier for use in radio frequency (RF) energy harvesting with body biasing by the RF input to control the threshold voltage of each transistor. The CMOS rectifier includes an energy harvesting antenna, and multiple rectifier stages. The antenna receives electromagnetic radiation from the environment and generates a DC current. The oscillating input current is an RF.sup.+ positive current during a first half cycle and is an RF.sup.? negative current during a second half cycle. A first rectifier stage includes a first capacitor connected to the RF.sup.+ positive current, a second capacitor connected to the RF.sup.? negative current and a cross coupled CMOS circuit connected to the antenna.

The invention relates to an operating device (1) for lighting means (8), having a circuit (101) for dividing a rectified alternating voltage to direct voltages of lower levels, wherein the circuit (101) comprises a PFC block comprising a plurality of half bridge converters (102, 103, 104) that are arranged such that the sum of the input voltage drops across the half bridge converters (102, 103, 104) corresponds to the value of the rectified alternating voltage, wherein the circuit (101) is the first active stage in a power supply for the lighting means (8).

A wireless power receiving terminal and a wireless charging system are disclosed. A switch is arranged between any one of the input ports and any one of the output ports of a full-bridge rectifying circuit for switching the operation mode of the rectifying circuit. The full-bridge rectifying circuit operates normally when the switch is turned off. A portion of rectifying components in the full-bridge rectifying circuit operate in a half-bridge multiplying mode and the other portion of the rectifying components are short-circuited and do not operate when the switch is turned on. Thus, the rectifying mode of the rectifying circuit and then an output voltage of the rectifying circuit are adjustable, and the operation voltage range of the wireless electric energy receiving terminal is expanded and the wireless power receiving terminal can operate normally when the magnetic field intensity is relatively high or relatively low. And at the meanwhile, it is also possible to provide a post-stage circuit (such as DC-DC converter) with relatively small operation voltage range to reduce the cost.

According to one embodiment, a controller determines the polarity of the input voltage detected by an input voltage detector. Then, when the polarity of the input voltage is positive, the first switch is subject to pulse driving, and when the polarity of the input voltage is negative, the second switch is subject to pulse driving, where the pulse driving is carried out at an on/off timing determined on the basis of the respective detection outputs of an input voltage detector, an input current detector, an output voltage detector, and an output current detector.

Wall mountable touch panels are described. In one embodiment, a wall mountable touch panel for controlling a load device includes a touch sensor configured to receive a user touch input and to control the load device based on the user touch input and a power interface configured to receive a low-voltage direct current (DC) power signal for powering the touch sensor. Other embodiments are also described.

A harmonic harvesting circuit design for harvesting unrectified AC power contained in the fundamental and harmonic frequencies at the output of conventional rectifying circuits.

An electrical circuit has a first integrated AC switch circuit connecting a first load to an AC voltage when the first integrated AC switch circuit is ON and a second integrated AC switch circuit connecting a second load to the AC voltage when the second integrated AC switch circuit is ON. The first integrated AC switch circuit generates a first DC voltage across a first capacitor and provides a pulse signal. When a VCCE pin of the second integrated AC switch circuit is coupled to a reference ground, a second capacitor is charged by the second integrated AC switch circuit to provide a second DC voltage. And when the VCCE pin of the second integrated AC switch circuit is floating or pulls high, the second capacitor is charged by the pulse signal.

An electrical power conversion system for converting a high voltage from a HV electrical power supply to a low voltage is disclosed. In an embodiment, the electrical power conversion system includes at least one power converter and at least one RC network including a plurality of resistive components and a plurality of capacitive components electrically connected in series. In an embodiment, the at least one RC network is in series connection with the at least one power converter and the at least one RC network and at least one power converter are arranged to be connected across a line potential of the HV electrical power supply.