One or more embodiments relate to a control circuit for an input filter circuit in a switch mode power supply comprising a power switch and a switch controller to control the power switch to provide a regulated output voltage and current to a load. The control circuit, also referred to as a filter control circuit, can be used to detect a high voltage surge at its input and disconnect a capacitor in the input filter circuit from an input return, thereby protecting the input filter capacitor and the SMPS from damage. According to certain aspects, the control circuit can be integrated with the switch controller. Additionally, the control circuit can provide power to the switch controller at start-up.

A bulk capacitor circuit for an AC input AC/DC Switching Mode Power Supply, such as an AC/DC adapter/charger without active power factor correction, is provided, comprising a plurality of bulk capacitors having different voltage ratings, and driver and control circuitry comprising AC input voltage sensing and comparator circuitry, which enables selective connection of one or more of the plurality of bulk capacitors, responsive to a sensed AC input voltage range. A startup circuit provides power to the driver circuit initially, so that the AC input voltage can be determined before power-up and enabling of the DC/DC converter. This solution provides for a reduction in capacitor volume, with associated improvement in the power density of an isolated AC/DC power supply, while the startup circuit ensures that an appropriate bulk capacitance is connected at startup for low line AC input, to maintain the ripple voltage in an appropriate range for reliable operation.

A prevention switching device is provided. The apparatus includes a switching circuit and a controller. The switching circuit includes a switching relay capable of switching a connection destination of a first power conversion circuit other than a second power conversion circuit among the plurality of power conversion circuits between a phase corresponding to the first power conversion circuit and a certain phase of the external power supply. The second power conversion circuit corresponds to the certain phase of the external power supply. The controller controls an operation of the switching relay at a zero-crossing time of an AC voltage estimated based on the AC voltage.

The present invention relates to AC-DC conversion in power electronics. In particular, the present invention is directed at a thyristor rectifier, which may be employed in an electric motor drive. The rectifier includes three thyristors and three diodes, wherein the thyristors are connected to a positive rectifier output and the three diodes are connected to a negative rectifier output. The present invention also relates to an electric motor drive comprising a corresponding thyristor rectifier. In general, the present invention may be used in a frequency converter for an electric motor drive, but it can also be used in non-drive application.

The disclosure relates to a circuit assembly (1) for intermediate circuit balancing of an intermediate circuit voltage UZK of a DC intermediate circuit fed by an alternating mains voltage UN for supplying a voltage to one or more devices, comprising a. a voltage divider (SP) configurable in terms of the voltage divider ratio and consisting of a plurality of electric two-terminal devices (R1, R2, . . . , R6) by which the intermediate circuit voltage UZK is divided into voltage portions at each two-terminal device, b. at least one first intermediate circuit capacitor (C1) chargeable to a first portion UZK,1 of the intermediate circuit voltage UZK, c. at least one second intermediate circuit capacitor (C2) chargeable to a second portion UZK,2 of the intermediate circuit voltage UZK.

An AC-DC converter circuit can include a plurality of passive components configured to convert AC to DC and to non-linearly regulate output DC voltage to about a selected maximum throughout an AC input voltage range and/or generator frequency. The plurality of passive components can be configured to also limit power loss as a function of load on a DC side.

A switching device is provided. The apparatus includes a switching circuit and a noise filter. The switching circuit is capable of switching a connection destination of a first power conversion circuit other than a second power conversion circuit among the plurality of power conversion circuits between a phase corresponding to the first power conversion circuit and a certain phase of the external power supply. The second power conversion circuit corresponds to the certain phase of the external power supply. In the noise filter, a capacitor is provided on a side of the multiple-phase AC supply of the switching circuit.

A system for controlling delivery of power to a load includes a master control unit (MCU) and a synchronous solid-state relay. The MCU causes the relay to close when the voltage delivered to the relay is at a zero crossing state. The MCU causes the relay to open at either (a) the moment when the voltage delivered to the relay is at a zero crossing state, or (b) the moment that the current delivered to the relay is both over a threshold level and at a zero crossing state.

An improved electrical power conversion system converts a high voltage (HV) from a HV electrical power supply to a low voltage. The electrical power conversion system includes at least one power converter and at least one RC network connected in series. The RC network includes a plurality of resistive components and a plurality of capacitive components electrically connected in series. 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.

A shorting cap apparatus is provided for enabling remote application of power, by an external system, to a load connected to the shorting cap apparatus while protecting components of the external system from potential damage due to high inrush current to the load. The shorting cap apparatus comprises a housing, a connector, and inrush current protection circuitry. The connector of the shorting cap apparatus may be connected to a corresponding connector associated with the load. Once the external system applies power, the protection circuitry provides a time delay to allow the load to sufficiently charge via a first set of resistors of the protection circuitry over a period of time before a set of switches of the protection circuitry are transitioned to a conducting state.