Fujitsu Corporation

Other

Fujitsu Access Limited

Fujtsu Denso Limited

Shindengen Electric Mfg., Co., Ltd.

Hiroshi Shimamori

Kazuhiko Itakura

Susumu Eguchi

Kazutoshi Fuchigami

Shigeharu Yamashita

Yusaku Fujiishi

Sentarou Tokimi

Hiroyuki Suzuki

Shinichi Ohtsu

Koichi Onodera

Kazuya Okamoto

Tsunehiro Ohno

Shinichi Otsu

Isamu Aoki

Ryuichi Yanagisawa

Tohru Futakawa

A power supply circuit includes a first power supply line that couples a first input node from which first input power is input and an output node to each other, a second power supply line that couples a second input node from which second input power is input and the output node to each other, a power limit of the second input power being higher than that of the first input power, a converter that is inserted in the first power supply line and that converts a voltage of the first input power input from the first input node to a higher voltage or a lower voltage, an adjustment circuit that adjusts an output voltage of the converter to a voltage higher than a voltage of the second input power input from the second input node.

Power supply circuit and electronic device

A switching power supply includes: a resonant circuit; a switching circuit including a switching element and configured to supply a voltage to the resonant circuit; a smoothing circuit configured to smooth a voltage output from the resonant circuit and outputs an output voltage; a resonance controller configured to, when a control instruction signal is input, cause the switching element to be turned on and off at a first frequency in such a manner that the output voltage becomes a specific voltage; and a controller configured to discontinuously output the control instruction signal to the resonance controller at a second frequency after an operation instruction signal is input until the output voltage becomes higher than a threshold voltage, and continuously output the control instruction signal to the resonance controller after the output voltage becomes higher than the threshold voltage until the operation instruction signal is not input.

Switching power supply, method for controlling switching power supply, and power supply system

A function expansion device is electrically connected to an electronic apparatus by being inserted in a socket included in the electronic apparatus and expands a function of the electronic apparatus. The function expansion device includes a substrate on which a component is mounted, a first connecting terminal that is formed at an end portion of the substrate and is electrically connected to a first signal line that connects the electronic apparatus and the component in a one-to-one fashion, a second connecting terminal that is formed at the end portion of the substrate and is electrically connected to a second signal line that connects the electronic apparatus and the component redundantly, and a protection member that is formed to cover only the second connecting terminal.

Function expansion device, manufacturing method thereof and electronic apparatus system

A mounting method for mounting an electronic component on a printed circuit board, the mounting method includes fixing a lower surface of a magnet panel to a magnetic body included in the electronic component by a magnetic force, seizing the electronic component by attracting a part of an upper surface of the magnet panel to an attaching unit, determining a position of the attracting unit to place the electronic component at a predetermined position with respect to the printed circuit board and releasing the attracting unit from the upper surface of the magnet panel.

Electronic component mounting method

A power supply to be connected in parallel to one or more other power supplies so as to share with the other power supplies in supplying load current to a load is disclosed. The power supply includes a load current comparison part including a first input terminal and a second input terminal and outputting a difference in level between a first signal applied to the first input terminal and a second signal applied to the second input terminal. The load current comparison part includes a differential amplifier. A first input terminal of the differential amplifier is connected to a first input terminal of the differential amplifier of each of the other power supplies. A signal indicating a load current supplied by the power supply is input to a second input terminal of the differential amplifier. A non-directional impedance element is inserted between the first and second input terminals of the differential amplifier.

Power supply

To reduce pattern resistance including a secondary winding in a power supply module having a pair of secondary windings transformer-coupled with a primary winding. The pair of secondary windings coupled with a primary winding through a transformer is drawn out in both directions each other, and further disposed on different layers. Also, output pattern films are disposed on both sides of the second and third layers, so that pattern films of wide shape can be produced.

Power supply module and electronic apparatus using the same

A reference voltage register stores a reference value Vref indicating the output voltage Vout of a power supply circuit. A digital filter amplifies the difference between the output voltage Vout from the power supply circuit and the reference value Vref stored in the reference voltage register. A pulse width computation unit computes the duty such that the output voltage Vout matches the reference value Vref, and generates the on-time of a pulse signal corresponding to the duty. A reference value operation unit updates the reference voltage register depending on the output current from the power supply circuit or the temperature around the power supply circuit.

Power supply apparatus having a reference voltage register and method of controlling

A card edge connector comprises a connector body and a conductive pad, and is constructed such that the conductive pad terminates at a predetermined distance from the end of the tip portion of the connector body, and that there is further provided a protective pad, adjacent to the terminating portion of the conductive pad, which is formed at the same time with the formation of a wiring pattern in a post-fabrication step of the wiring pattern. Using the card edge connector, an electric card and an electric equipment are also provided.

Card edge connector, method of manufacturing same, electronic card and electronic equipment

This electric-power supplying device comprises switching elements, rectifying elements, and a control circuit. The switching elements are switched according to a switching pulse so as to perform a rectification. The rectifying elements are connected in parallel with the switching elements so as to perform a rectification. The control circuit alters the switching pulse gradually upon switching between the rectification performed by the switching elements and the rectification performed by the rectifying elements.

Electric-power supplying devices switching between a synchronous rectification and a diode rectification by gradually altering a switching pulse

A electric power conversion unit generates a DC output according to a pulse signal from a PWM unit. An A/D conversion unit converts the output voltage from the electric power conversion unit into digital data. A digital filter amplifies the difference between the digital data output from the A/D conversion unit and a reference value. A pulse width computation unit computes the on-time of a pulse signal provided to the electric power conversion unit based on the output from the digital filter. The on-time is written to an on-time register. The PWM unit generates a pulse signal according to the cycle set in a cycle register and the on-time written to the on-time register, and provides the signal to the electric power conversion unit.

Power supply apparatus and method of controlling power supply circuit for generating a DC output

The DC output of a power conversion unit is controlled based on a pulse signal generated by a PWM unit. An operations unit detects an output current Iout, and determines the operation mode of a load based on the detected current value. When the output current Iout is weak, a value smaller than usual is written to a cycle register. The PWM unit generates a pulse signal according to the data stored in the cycle register and an on-time register.

Power supply apparatus and method of controlling power supply circuit

A synchronous rectifying type DC-DC converter including an auxiliary winding, provided on a secondary side of a transformer, for supplying voltages assuming polarities opposite to each other to control terminals of a rectifying switch and of a fly wheel switch, and the rectifying switch and the fly wheel switch are so constructed as not to be turned ON/OFF by a voltage generated on a supply path of an electric current to a load from a secondary winding of the transformer. When connecting a plurality of DC-DC converters in parallel and operating these converters in parallel, an output of any one of the converters stops, and, even if outputs of the other DC-DC converters are inputted to the DC-DC converter concerned and the electric current flows into the current supply path, a voltage based on the above current is not applied to control terminals of the rectifying switch and of the fly wheel switch. The rectifying switch and the fly wheel switch are not therefore turned ON. Accordingly, a large quantity of electric current is prevented from flowing into the DC-DC converter concerned.

DC/DC converter with improved operation of plural parallel synchronous rectifiers

A switching power supply unit controls an output voltage of a power supply without monitoring an output voltage. The switching power supply unit includes a pulse width modulator for generating a control signal to turn on and off a switching transistor. A central processing unit outputs a modulation signal to control the pulse width modulator while sensors detect an input voltage, an output current and a peripheral temperature. A table is used by the central processing unit to store information about a relation between the detected values from the sensors and an ON time of the switching transistor. The central processing unit then selects an ON time of the switching transistor from the table according to values detected by the respective sensors to thereby provide control for switching the switching transistor on and off. The switching transistor is switched according to the selected time and to thereby switch an input voltage in response to changes of an input voltage, an output current and a peripheral temperature without monitoring an output voltage. Furthermore, the output voltage can be maintained with stability at a desired output voltage.

Growing community of inventors

Kawasaki, Japan

Hiroshi Shimamori