An active common mode filter is configured to be positioned between a power supply and a switching converter-device/load for reducing common mode noise. The active common mode filter includes an active capacitor that has a sensing stage including one or more sensing capacitors, an amplifying stage including a common collector amplifier for mitigating an input voltage divider effect coupled to a common emitter amplifier for providing high gain, and an injection stage including one or more injection capacitors. Depending on the required attenuation in different applications, a multistage active common mode filter may be formed with a necessary number of stages, each stage including an active capacitor and an inductor.

An active common mode filter is configured to be positioned between a power supply and a switching converter-device/load for reducing common mode noise. The active common mode filter includes an active capacitor that has a sensing stage including one or more sensing capacitors, an amplifying stage including a common collector amplifier for mitigating an input voltage divider effect coupled to a common emitter amplifier for providing high gain, and an injection stage including one or more injection capacitors. Depending on the required attenuation in different applications, a multistage active common mode filter may be formed with a necessary number of stages, each stage including an active capacitor and an inductor.

An auxiliary power supply device for an inverter with a plurality of power modules connected in parallel is disclosed. The auxiliary power supply device includes: a plurality of soft-start circuits, each coupled to a DC port of a corresponding power module; a plurality of distributed auxiliary power supplies, each having an input terminal coupled to the DC port of the corresponding power module; and a centralized auxiliary power supply having an input terminal coupled to an AC side of the inverter, and an output terminal coupled to a DC side of the inverter. By replacing auxiliary power supplies on the AC sides of all power modules with the centralized auxiliary power supply and omitting soft-start circuits on the AC sides of all power modules, the present invention improves system performance in cost, volume, loss, and electromagnetic compatibility.

A power converter including an inverter for converting electric power output from a power supply, a first power feeding bus connected to the inverter and to the positive side of the power supply, a second power feeding bus connected to the inverter and the negative side of the power supply, and a plurality of connection circuits including a resistant member and a capacitive member which are connected in series, connected between the first power feeding bus and the second power feeding bus, and having at least two or more different impedances.

Even when a grounding capacitor is included at either end of a common mode coil, there is noise that flows from a load into a metal frame, and there is a need to restrict an amount of noise propagating to a system power supply. Because of this, a noise loop is formed of a rectifier circuit, an inverter, a first electrical wire that connects a positive polarity side of the rectifier circuit and the inverter, a second electrical wire that connects a negative polarity side of the rectifier circuit and the inverter, a ground wire terminal that can connect a load connected to an output terminal or the inverter, and a conductive plate that connects at least one or the first electrical wire and second electrical wire and the ground wire terminal.

A power supply including: an AC input power connector; an AC-DC converter circuit coupled to the AC input power connector; a constant-current constant-voltage control unit configured to receive DC power from the AC-DC converter circuit; a light emitting diode (LED) lamp unit configured to receive power from the constant-current constant-voltage control unit; and a capacitor coupled in parallel with the LED lamp unit.

A power supply including: an AC input power connector; an AC-DC converter circuit coupled to the AC input power connector; a constant-current constant-voltage control unit configured to receive DC power from the AC-DC converter circuit; a light emitting diode (LED) lamp unit configured to receive power from the constant-current constant-voltage control unit; and a capacitor coupled in parallel with the LED lamp unit.

An apparatus is disclosed for harvesting ringing energy. In an example aspect, the apparatus includes a bootstrap circuit. The bootstrap circuit includes a bootstrap capacitor and a bootstrap switch. The bootstrap switch includes a first terminal configured to accept an input voltage. The bootstrap switch also includes a second terminal coupled to the bootstrap capacitor. The bootstrap switch additionally includes a body diode comprising an anode coupled to the first terminal and a cathode coupled to the second terminal. The bootstrap switch is configured to be in an open state to charge the bootstrap capacitor via the body diode. The bootstrap switch is also configured to provide a voltage at the second terminal of the bootstrap switch. The voltage is greater than an average of the input voltage.

The power conversion device includes: a main circuit having first and second wiring layers formed respectively on both surfaces of a base board, mounted parts mounted on the first and second wiring layers, and first and second GND layers formed respectively, between external- and internal-layer portions of the base board and in regions corresponding to the mounted parts each being a mounted part which forms a circuit other than a circuit having an inductance component as a lumped constant, and to the first and second wiring layers; and a cooler attached to the base board by means of fixing screws through a first through-hole created in an end portion of the board; wherein the first and second GND layers are each formed so that creepage distance is created around a second through-hole in which a lead insertion part that mutually connects the first and second wiring layers is inserted.

A voltage converter includes an input voltage line; an inductor coupled to the input voltage line; transistors coupled to the inductor; an output voltage line coupled to at least one of the transistors; a current sensor coupled to at least one of the input voltage line, the inductor, or the output voltage line; and a comparator coupled between the current sensor and the transistors. A DC-DC converter may include a voltage converter having an inductor and a plurality of transistors and configured to convert an input voltage into a power voltage and output the power voltage to an output terminal, an input current sensor configured to sense the input current of the converter, and a controller configured to change the slew rate of an inductor voltage in response to the input current of the converter and a preset reference current.