Hitachi, Ltd.

Yosuke Tsuyuki

Akihiko Kanouda

Takashi Sase

Ryohei Oguro

Hiroyuki Shoji

A storage apparatus writes data to a storage drive or reads data from a storage drive in response to an I/O request sent from a server. The storage apparatus includes a plurality of AC-DC power supplies supplying the storage drive with drive power is provided with a plurality of power supply paths provided for the respective AC-DC power supplies. A plurality of gate units are provided to the respective power supply paths and configured to stop supplying drive power to the storage drive through the corresponding power supply path when detecting voltage abnormality in the drive power supplied from the AC-DC power supply to the storage drive. The power supply paths allow each of the storage drives belonging to a same RAID group to receive the supply of the drive power from the AC-DC power supplies through different power supply paths, respectively.

Storage apparatus

A power-supply unit including a transformer, a full bridge circuit having four arm switches on a primary side of the transformer, a rectifier and smoothing circuit including two synchronous rectifier switches on a secondary side of the transformer, a choke coil, and a capacitor, an output terminal in the rectifier and smoothing circuit, a control circuit controlling ON/OFF of the four arm switches of the full bridge circuit and the two synchronous rectifier switches of the rectifier and smoothing circuit, a resonant inductor including a leakage inductor component and a parasitic inductor component on the primary side of the transformer, and a resonant capacitor, and in which the control circuit includes a timing variable unit which varies switching timings of the two synchronous rectifier switches of the rectifier and smoothing circuit based on an output current flowing in the output terminal provided in the rectifier and smoothing circuit.

Power-supply unit, hard-disk drive, and switching method of the power-supply unit

A power supply device includes two buck converters, having a coupling inductor Lo composed of two mutually-coupled inductors L, L, and a output capacitor Co, wherein of the two buck converters, a first buck converter is operated during a positive half-cycle period of an AC input voltage, and a second buck converter is operated during a negative half-cycle period of the AC input voltage, to obtain a DC output voltage at both ends of the output capacitor Co from the AC input voltage, is provided. Herewith, is provided the power-supply device using the buck converter, which can be reduced in the number of components and produced in a low cost without a diode bridge.

Supply device, and LED lighting equipment using the same

A storage apparatusthat writes data to a storage driveor reads data from a storage drivein response to an I/O request sent from a server apparatus, and includes a plurality of AC-DC power supplies to supply the storage drivewith drive power is provided with a plurality of power supply paths provided for the respective AC-DC power suppliesconfigured to supply the storage drivewith drive power from the AC-DC power supplies, respectively and a plurality of gate units provided to the respective power supply paths and configured to stop supplying drive power to the storage drivethrough the corresponding power supply path when detecting voltage abnormality in the drive power supplied from the AC-DC power supplyto the storage drive. For example, the power supply paths are provided to allow each of the storage drivesbelonging to a same RAID groupto receive the supply of the drive power from the AC-DC power suppliesthrough different power supply paths, respectively.

A power converter includes a first inductor, a rectifier arm, a first switch arm including a first and second switch circuits, a second switch arm including a third switch circuit and a first capacitor, a LC serial circuit, a Transformer, a rectification and smoothing circuit connected to secondary winding of the transformer, and a control circuit to perform on-off control of the three switch circuits. The rectifier arm, the first and second switch arms and the LC serial circuit are connected in parallel with each other. The LC serial circuit and primary winding of the transformer are connected. AC power supply is connected to the rectifier arm via the first inductor. The control circuit includes an output voltage control circuit to control output voltage at specific setting value, an intermediate voltage control circuit to control intermediate voltage at specific setting value, and a power factor correction control circuit.

Power converter, control method of power converter, and hard disk drive

A storage system includes one or more first power supplies which receive power from the first input and supplies power to each of multiple load groups through multiple first paths and multiple second power supplies which receive power from the second input and supplies power to each of the multiple load groups through multiple second paths. Each load group is comprised of at least one load, and each load is a storage device. Power is supplied from different second power supplies respectively to two or more load groups to which power is supplied from the first power supply through two or more first paths.

Storage system

A storage system comprises multiple physical storage devices, and a power supply for the multiple physical storage devices. Each physical storage device requires an input of a first voltage and an input of a second voltage that is a lower voltage than the first voltage. The power supply comprises a first power supply circuit that is made redundant and a second power supply circuit that is made redundant. Each first power supply circuit outputs a first voltage, which is input to the respective physical storage devices. Each second power supply circuit outputs a second voltage to a storage device group (two or more physical storage devices of the multiple physical storage devices) corresponding to this second power supply circuit. Each second power supply circuit is isolated from a circuit board comprising the first power supply circuit.

Power supply of storage system

A first-order feedback control power supply apparatus being arranged in such a manner that when the apparatus is driven under light load condition, a current flowing through an inductor is detected by employing a second CR smoothing filter; when the present load condition is judged as a light load condition based upon the detected inductor current, both upper-sided/lower-sided power MOSFETs and a PWM oscillator are turned OFF so as to be brought into sleep states; when an output voltage of the power supply apparatus is lowered and the lowered output voltage reaches a lower limit threshold of a transient variation detecting circuit, the upper-sided power MOSFET is turned ON to recover the output voltage; and when the output voltage of the power supply voltage reaches a predetermined voltage, the upper-sided power MOSFET is turned OFF so as to be again brought into the sleep state.

Power supplying apparatus including a pulse-width modulation oscillator and smoothing filters

Zero volt switching during a light load is performed in such a manner that through an ON/OFF control of switches provided for a full bridge circuit and the synchronous rectifier switches in a rectifier and smoothing circuit, a resonant peak voltage necessary for the zero voltage switching determined by the output current flowing to output terminals, a resonant inductor and a resonant capacitor capacitance is ensured so that an energy accumulated in the rectifier and smoothing circuit is returned to the full bridge circuit so as to act as equivalent as when the output current is increased and to increase the current flowing through the full bridge circuit.

Growing community of inventors

Odawara, Japan

Yosuke Tsuyuki