A switching converter includes: a reactor having one end to be connected to an AC power source; and a rectifier circuit connected to an opposite end of the reactor, the rectifier circuit converting a power source voltage applied by the AC power source into a DC voltage. The rectifier circuit includes a first leg and a second leg connected in parallel to the first leg. The first leg includes a first upper-arm element and a first lower-arm element connected in series. The second leg includes a second upper-arm element and a second lower-arm element connected in series. A snubber circuit including a resistor and a capacitor is connected to each of upper and lower-arm elements in one of the first and second legs. No snubber circuit is connected to upper and lower-arm elements in another of the first and second legs.

A system for providing power from an AC power supply to an external load. The system includes a current limiter circuit, connected to an input of a switched-mode power supply. The system includes the switched-mode power supply that provides a first voltage signal and a second voltage signal. The system includes a supervisor circuit that is connected to the first output of the switched-mode power supply and coupled to a relay control circuit. The supervisor circuit monitors the first voltage signal and enables the relay control circuit. The relay control circuit provides a first voltage corresponding to the first voltage signal to a first voltage rail and provides a second voltage corresponding to the second voltage signal to a second voltage rail. A relay powered by a connection to the first voltage rail or the second voltage rail connects the AC power supply to an external load.

A power supply circuit for an x-ray production system, which has an inverter circuit with an output for connecting the inverter circuit with an x-ray source of the x-ray production system, includes a rectifier circuit including an input to connect the rectifier circuit with a power supply network, the rectifier circuit further including an output to connect to an input of the inverter circuit; and a backup circuit including a plurality of electrical energy storage cells, the plurality of electrical energy storage cells being connectable in series between the input of the inverter circuit and the output of the rectifier circuit.

A power factor correction (PFC) circuit includes an alternating current input circuit, a totem-pole PFC circuit, an input sampling circuit, an output sampling circuit, and a PFC control protection circuit. A first output terminal of the alternating current input circuit is respectively connected to a first input terminal of the totem-pole PFC circuit and a first input terminal of the input sampling circuit.

The present invention relates to a switched-mode power supply that comprises a detection circuit for detecting a coupling of an electrical device to the switched-mode power supply and a decoupling of the electrical device from the switched-mode power supply, a switch for controlling the supply of electric power to the switched-mode power supply, a control circuit for controlling the switch, the control circuit being configured to turn on the switch when the coupling of the electrical device has been detected, and to turn off the switch when the decoupling of the electrical device has been detected, and a supply circuit for providing a supply voltage to the detection circuit and the control circuit.

Power conversion systems, methods and precharge systems are disclosed to charge a DC bus capacitor, including thyristors and reverse diodes coupled in AC circuit paths between AC input lines and a rectifier, a precharge resistor coupled in one or more of the AC circuit paths, and a controller to turn all the thyristors off to allow the DC bus capacitor to charge through the precharge resistor, and to turn all the thyristors on when the DC bus voltage reaches a non-zero threshold value.

A converter configured to supply an energy consuming element during an operating phase and may charge a capacitor during a pre-charging phase prior to the operating phase. The converter may have a power factor correction circuit having the capacitor and thyristors. The converter may also have a control system configured to control the pre-charging phase. The control system may have a control unit configured to, during the operating phase, detect the state of charge of the capacitor, and generate a control signal configured to control the thyristors as a function of the state of charge of the capacitor.

An overvoltage protection (OVP) module includes: an OVP assembly comprising a plurality of OVP units; a frame mounted to the OVP assembly; a terminal block with a plurality of first electrical ports and a plurality of second electrical ports, the terminal block mounted to the frame; and a plurality of electrical conductors, each conductor electrically connected between one of the first electrical ports of the terminal block and a respective OVP unit.

Precharging systems and methods are presented for precharging a DC bus circuit in a power conversion system, in which precharging current is connected through a precharging resistance coupled between only a single AC input line and the DC bus circuit when the DC bus voltage is less than a non-zero threshold, and a controller individually activates controllable rectifier switching devices when the DC bus voltages greater than or equal to the threshold using DC gating or pulse width modulation to selectively provide a bypass path around the precharging resistance for normal load currents in the power conversion system.

A power tool is configured to receive power from a power supply. The power tool may include a rectifier that may output a rectified signal to a DC power bus. A switching arrangement may operate to deliver electric power from the DC power bus to an electric motor. A switch path may be electrically coupled in parallel with the rectifier on the DC power bus. The switch path includes an auxiliary capacitor in series with a switch and a state of the switch controls a discharging path for the auxiliary capacitor. A switch control circuit may be configured to detect voltage associated with at least one of the AC power supply or the DC power bus and to control state of the switch in accordance with magnitude of the detected voltage.