In the present uninterruptible power supply apparatus (U1), in a power failure of a commercial AC power supply (41), a switch (1) is turned off to electrically cut off the commercial AC power supply (41) from an AC input filter (2), and when DC voltage (ΔE=Ep−En) that is the difference between terminal-to-terminal voltages (Ep, En) of first and second capacitors (C1, C2) exceeds a threshold voltage (ETH), first and second IGBT devices (Q1, Q2) or third and fourth IGBT devices (Q3, Q4) included in the converter (3) are turned on and off to reduce DC voltage (ΔE).

An AC capacitor is coupled to a totem-pole type PFC circuit. In response to detection of a power input disconnection, the PFC circuit is controlled to discharge the AC capacitor. The PFC circuit includes a resistor and a first MOSFET and a second MOSFET coupled in series between DC output nodes with a common node coupled to the AC capacitor. When the disconnection event is detected, one of the first and second MOSFETs is turned on to discharge the AC capacitor with a current flowing through the resistor and the turned on MOSFET. Furthermore, a thyristor may be simultaneously turned on, with the discharge current flowing through a series coupling of the MOSFET, resistor and thyristor. Disconnection is detected by detecting a zero-crossing failure of an AC power input voltage or lack of input voltage decrease or input current increase in response to MOSFET turn on for a DC input.

Disclosed herein are a wireless power transmission method and device in which rectifier performance of an Internet of things (IOT) sensor is taken into consideration. The method and device may be configured to identify rectifier performance of each of a plurality of IOT sensors, determine power to be transmitted to each of the IOT sensors based on a value for enabling power, output by the rectifier, to reach a predetermined maximum value based on the rectifier performance, and transmit the power to each of the IOT sensors in the form of electromagnetic waves.

Disclosed herein are a wireless power transmission method and device in which rectifier performance of an Internet of things (IOT) sensor is taken into consideration. The method and device may be configured to identify rectifier performance of each of a plurality of IOT sensors, determine power to be transmitted to each of the IOT sensors based on a value for enabling power, output by the rectifier, to reach a predetermined maximum value based on the rectifier performance, and transmit the power to each of the IOT sensors in the form of electromagnetic waves.

A transmission and distribution system with electric shock protection function includes a transmitting terminal and a receiving terminal. The transmitting terminal includes a switch, a current measurer, a signal generator, and a controller. The receiving terminal includes a filter. The switch is coupled to a first DC power and a transmission line. The current measurer is coupled to the transmission line, and measures a current of the transmission line and provides a current signal. The signal generator provides a disturbance signal to the transmission line. The controller receives the current signal and controls the switch. If the controller determines that the current signal contains the disturbance signal, the controller turns off the switch.

A power factor correction switching power supply device includes a power factor correction circuit connected to an alternating-current input line, a first half-bridge capacitor circuit connected between lines of the AC input line, a second half-bridge capacitor circuit connected between lines of a direct-current output line that is closer to a load than a first output capacitor, a common mode choke coil disposed between the first output capacitor and the second half-bridge capacitor circuit, and an electric path configured to electrically connect a midpoint of the first half-bridge capacitor circuit and a midpoint of the second half-bridge capacitor circuit to form a noise balancing circuit. The noise balancing circuit has a potential different from a potential of a ground and is configured to balance common mode noise.

A power factor correction switching power supply device includes a power factor correction circuit connected to an alternating-current input line, a first half-bridge capacitor circuit connected between lines of the AC input line, a second half-bridge capacitor circuit connected between lines of a direct-current output line that is closer to a load than a first output capacitor, a common mode choke coil disposed between the first output capacitor and the second half-bridge capacitor circuit, and an electric path configured to electrically connect a midpoint of the first half-bridge capacitor circuit and a midpoint of the second half-bridge capacitor circuit to form a noise balancing circuit. The noise balancing circuit has a potential different from a potential of a ground and is configured to balance common mode noise.

Embodiments discussed herein refer to backwards compatible charging circuits and methods for charging a battery to a relatively high voltage level regardless of whether the charging station is capable of supplying power at that relatively high voltage level. The circuitry and methods according to embodiments discussed herein can use the onboard charging system to provide a voltage boosting path to increase the charge voltage from a legacy voltage level (e.g., a relatively low voltage level) to a native voltage level (e.g., a relatively high voltage level). When a native voltage charging station is charging the battery, the circuitry and methods according to embodiments discussed herein can use a native voltage path for supplying power, received from the charging station at the native voltage, to the battery.

Embodiments discussed herein refer to backwards compatible charging circuits and methods for charging a battery to a relatively high voltage level regardless of whether the charging station is capable of supplying power at that relatively high voltage level. The circuitry and methods according to embodiments discussed herein can use the onboard charging system to provide a voltage boosting path to increase the charge voltage from a legacy voltage level (e.g., a relatively low voltage level) to a native voltage level (e.g., a relatively high voltage level). When a native voltage charging station is charging the battery, the circuitry and methods according to embodiments discussed herein can use a native voltage path for supplying power, received from the charging station at the native voltage, to the battery.

A power supply system with current sharing includes a current sharing bus, a plurality of power supply units, and a plurality of controllers. The power supply units are connected to each other through the current sharing bus. Each power supply unit provides a current sharing signal value to the current sharing bus, and provides an output current to a load. Each controller receives current sharing signal values provided from other power supply units and current signal values corresponding to the output currents. When determining that the current signal value is less than a reference current sharing signal value, the controller increases an output voltage of the power supply unit to increase the output current. Otherwise, the controller decreases the output voltage to decrease the output current so that so that the output currents of the power supply units are shared to supply power to the load.