An isolated communications apparatus applied to a transformer. The transformer includes N first rectifier units and a second rectifier unit, and the isolated communications apparatus includes N first control units, a second control unit, and a signal convergence unit. The first control units are connected to the first rectifier units in a one-to-one correspondence. Each first control unit is connected to the signal convergence unit, and the signal convergence unit and the second control unit are connected through an optical fiber. The signal convergence unit is configured to: receive first data packets from the N first control units, send the first data packets to the second control unit, receive at least one second data packet from the second control unit, determine a first control unit corresponding to each second data packet, and send each second data packet to a corresponding first control unit.

The power conversion system includes a power conversion circuit, a power conversion control circuit including a charging control mode, and a command value generating part. The charging control mode is a mode in which the output voltage of the power conversion circuit is controlled so that an interconnection inductance receives an interconnection inductance voltage determined by the power supply voltage vector of the AC power supply and the voltage command value vector having a delay phase with respect to the power supply voltage vector and having a magnitude and a phase based on the command value. The command value generating part generates a second command value for operation of the charging control mode when the voltage of the storage battery falls below the over-discharge threshold.

The present disclosure uses a capacitive voltage divider to supply a voltage that can be more readily handled by main-stream semiconductor and magnetic components (generally less than 1000 volts). The divided system voltage, expected to be between 500 and 1000 volts, is then converted to a power supply voltage to be used by the measuring equipment. For safety reasons, this voltage is frequently required to be less than approximately 50 volts if it is delivered via a connectorized cable with exposed contacts.

A method for regulating input impedance of a switching regulator, the method comprising: obtaining, at an impedance controller: (a) a measured voltage value that is indicative of an input current of the switching regulator and (b) an input voltage of the switching regulator, wherein a ratio of the input voltage to the input current defines an actual input impedance of the switching regulator; generating a control signal by the impedance controller, in accordance with a difference between the actual input impedance of the switching regulator and a desired input impedance of the switching regulator, wherein the desired input impedance is a predefined impedance; and controlling a feedback node feeding the switching regulator, in accordance with the control signal, to realize an output voltage of the switching regulator for achieving the desired input impedance, wherein the feedback node is external to the switching regulator, thereby regulating the input impedance of the switching regulator externally to the switching regulator.

A transformer and a power supply device. In the transformer, the first secondary coil including: first and second plate coils; and a first holding portion formed therebetween, the second secondary coil including: third and fourth plate coils; and a second holding portion formed therebetween, the first secondary coil is arranged between the third and fourth coils, the ends of the first plate coil and third plate coil are connected by solder, and the ends of the second plate coil and fourth plate coil are connected by solder, when the secondary-side rectifier circuit is a center-tapped rectifier circuit, the first holding portion, the second holding portion, and the bus bar are connected by solder through the connection hole, when the secondary-side rectifier circuit is a rectifier circuit other than the center-tapped rectifier circuit, the first holding portion and the second holding portion are connected by solder through the connection hole.

An AC-DC power converter can include: a front-stage power circuit; a rear-stage power circuit configured to share one power switch as a main power switch with the front-stage power circuit, where the rear-stage power circuit is coupled to a load, and a first magnetic component of the front-stage power circuit and a second magnetic component of the rear-stage power circuit are not coupled in one conductive loop from a positive terminal of a DC input voltage to a negative terminal of the DC input voltage; and an energy storage capacitor coupled to the front-stage power circuit and the rear-stage power circuit, where a common node of the first and second magnetic components is directly coupled to the power switch.

Systems and methods for operating a transistor rectifier unit are provided. Aspects include providing a first transformer output and a second transformer output, providing a plurality of rectifier circuits, wherein the plurality of rectifier circuits comprises a first rectifier coupled to the first transformer output and a second rectifier coupled to the second transformer output, and wherein the first rectifier comprises a first output voltage and the second rectifier comprises a second output voltage, operating a plurality of switches based on a plurality of operational modes, wherein the plurality of operational modes comprises a first mode, a second mode, and a third mode, and wherein the plurality of switches comprises a first switch, a second switch, and a third switch.

The multi-voltage control assessor for providing a set of standard voltages useful in testing electrical devices and systems is disclosed. The Multi-Voltage Control Assesor (MVCA) is a portable, small suitcase sized device containing transformers, switches, safety devices and cabling that, when operated safely by a competent person, can provide common voltages to power controls, relays and small devices intended for troubleshooting purposes. It can also temporarily substitute for a control transformer for a critical device, as necessary. It is not recommended for this to be a full time use, only until a suitable replacement can be installed.

A charging device for charging an electric energy storage device includes a power supply circuit connected to a power supply, an alternating current conversion circuit configured to convert a current from the power supply connected to the power supply circuit to a first alternating current with a preset frequency value, a transformer configured to convert the first alternating current to a second alternating current, wherein a voltage value corresponding to the second alternating current being less than a voltage value corresponding to the first alternating current, and a direct current voltage conversion circuit configured to convert the second alternating current to a direct current with a waveform fluctuating in a preset range, so as to charge an electric energy storage device. The alternating current conversion circuit is connected to the power supply circuit, the transformer is connected to the alternating current conversion circuit, and the direct current voltage conversion circuit is connected to the transformer.

Disclosed is a power supply system, including: a high-voltage input power distribution cabinet, a high-low voltage conversion cabinet, and a low-voltage output and control cabinet, the high-low voltage conversion cabinet is provided with at least one high-voltage chamber provided with a high-voltage bus bar, at least one low-voltage chamber provided with a low-voltage bus bar, an insulating partition between the high-voltage chamber and the low-voltage chamber and a plurality of power supply modules; each of the power supply modules bridges the high-voltage and low-voltage chambers and includes a high-voltage cavity, a low-voltage cavity and an isolation unit, connecting terminals of the high-voltage and low-voltage cavities are respectively disposed corresponding to the high-voltage and low-voltage chambers and electrically connected to the high-voltage and low-voltage bus bars respectively, and the isolation unit is connected to one end of the high-voltage cavity and one end of the low-voltage cavity.