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Hiroyuki Shoji

Hiroyuki Shoji, Hitachi JP

Patent application numberDescriptionPublished
20080309301 Didirectional DC-DC converter and power supply apparatus with the same - A bidirectional DC-DC converter 12-18-2008
20090059622BI-DIRECTIONAL DC-DC CONVERTER AND METHOD FOR CONTROLLING THE SAME - A bi-directional DC-DC converter has a transformer for connecting a voltage type full bridge circuit connected to a first power source and a current type switching circuit connected to a second power source. A voltage clamping circuit constructed by switching elements and a clamping capacitor is connected to the current type switching circuit. The converter has a control circuit for cooperatively making switching elements operative so as to control a current flowing in a resonance reactor.03-05-2009
20090147541Complex Inductor and Power Supply Unit - A complex inductor according to the present invention changes its magnetic coupling polarity according to currents flowing its two inductors. The complex inductor includes a first magnetic member, around which first and third windings are formed, and a second magnetic member, around which second and fourth windings are formed. A first inductor is formed by connecting the first winding to the second winding, and a second inductor is formed by connecting the third winding to the fourth winding. The two magnetic members are made of a magnetic material having a magnetic permeability that gradually decreases as its magnetic flux density is increased. When the two windings are interconnected in a direction in which induced voltages generated in these windings by the current flowing in the second inductor weaken each other, the magnetic coupling polarity between the first and second inductors changes according to the current flowing in the inductors. The two inductors are magnetically coupled so that, when one of the two inductors stores energy, the current flowing in the other inductor increases, and when one of the two inductors releases energy, the current flowing in the other inductor decreases.06-11-2009
20100061122DC-DC CONVERTER - A small and efficient DC-DC converter is provided. In this DC-DC converter, passive elements such as an inductor and a capacitor can be reduced in size by reducing switching loss by a soft switching technology and increasing the drive frequency of a switching element. The DC-DC converter has a main switching element, a main diode and an auxiliary circuit that discharges the electric charges of the capacitance between the ends of the main switching element. The DC-DC converter includes an auxiliary inductor magnetically coupled with the main inductor, an auxiliary switching element that stores energy in the auxiliary inductor, and an auxiliary diode that discharges energy stored in the auxiliary inductor to the direct-current power source or the output side. The auxiliary inductor is coupled with the main inductor in the direction in which backward voltage is applied to the auxiliary diode when the main inductor discharges energy.03-11-2010
20100142228Bi-Directional DC-DC Converter and Control Method - A bi-directional DC-DC converter uses a transformer for both step-down and step-up operations. A switching frequency for operating a switching device is set separately for the step-down and step-up operations. When, for example, the switching frequency during the step-up operation is lower than the switching frequency during the step-down operation, the range in which the duty ratio in PWM control can be controlled is widened, compensating for step-up ratio insufficiency. Conversely, step-down ratio insufficiency is compensated for by making the switching frequency during the step-down operation lower than the switching frequency during the step-up operation.06-10-2010
20110013437DC-DC Converter And Its Controlling Method - A unidirectional DC-DC converter and method of control thereof. The converter includes a DC power-supply, a buck converter circuit having a first main switching element, a boost converter circuit having a second main switching element, a first snubber capacitor, a first inversely-parallel diode, a control device, and an output diode.01-20-2011
20110019440BI-DIRECTIONAL DC-DC CONVERTER AND METHOD FOR CONTROLLING THE SAME - A bi-directional DC-DC converter has a transformer for connecting a voltage type full bridge circuit connected to a first power source and a current type switching circuit connected to a second power source. A voltage clamping circuit constructed by switching elements and a clamping capacitor is connected to the current type switching circuit. The converter has a control circuit for cooperatively making switching elements operative so as to control a current flowing in a resonance reactor.01-27-2011
20110128759BI-DIRECTIONAL DC-DC CONVERTER AND METHOD FOR CONTROLLING THE SAME - A bi-directional DC-DC converter has a transformer for connecting a voltage type full bridge circuit connected to a first power source and a current type switching circuit connected to a second power source. A voltage clamping circuit constructed by switching elements and a clamping capacitor is connected to the current type switching circuit. The converter has a control circuit for cooperatively making switching elements operative so as to control a current flowing in a resonance reactor.06-02-2011
20110228564GATE DRIVE CIRCUIT OF THE VOLTAGE DRIVE TYPE SEMICONDUCTOR ELEMENT AND POWER CONVERTER - A power converting apparatus having a gate drive circuit including a push-pull circuit consisting of two transistors at its output stage; a diode connected in series with the push-pull circuit; a gate power source connected in parallel with the series circuit of the push-pull circuit and the diode; a negative voltage generating circuit connected in parallel with the push-pull circuit; a transistor connected between the output terminal of the negative voltage generating circuit and the negative terminal of the gate power source, wherein the output voltage of the push-pull circuit is switched from positive polarity to negative polarity and vice versa depending on the signal applied to the base terminals of the transistors.09-22-2011

Patent applications by Hiroyuki Shoji, Hitachi JP

Hiroyuki Shoji, Osaka JP

Patent application numberDescriptionPublished
20100033113LED DRIVE CIRCUIT - An LED drive circuit that drives an LED is provided with: a rectifying circuit that converts an alternating voltage into a pulsating current; a constant current circuit; and an over-temperature protection portion that limits an output of the constant current circuit, wherein the LED and the constant current circuit are connected in series on an output side of the rectifying circuit.02-11-2010
20100090604LED DRIVE CIRCUIT, LED ILLUMINATION COMPONENT, LED ILLUMINATION DEVICE, AND LED ILLUMINATION SYSTEM - An LED drive circuit is an LED dive circuit that receives an alternating voltage to drive an LED, and includes a current remove portion that removes a current from a current supply line that supplies an LED drive current to the LED. If an input current to the LED drive circuit is an unnecessary current, the LED does not light because of current removal by the current remove portion. If the input current to the LED drive circuit turns into the LED drive current from the unnecessary current, the current remove portion decreases the amount of current removed.04-15-2010
20120043902LED DRIVER CIRCUIT AND LED LIGHTING DEVICE USING THE SAME - Provided is an LED driver circuit, to be connected to an AC power supply via a phase-control dimmer, for driving an LED load, including: a switching power supply part including a switching element and a switching current detection part; an LED current detection part; a first control part for controlling and switching the switching element so that a switching current has a desired current value based on a detection signal of the switching current detection part; a second control part for controlling and switching the switching element so that an LED current has a desired current value based on a detection signal of the LED current detection part; and a switch part for switching between control performed by the first control part when the phase-control dimmer is set to high brightness dimming and control performed by the second control part when the phase-control dimmer is set to low brightness dimming.02-23-2012

Hiroyuki Shoji, Hitachi-Shi JP

Patent application numberDescriptionPublished
20100052423BIDIRECTIONAL DC-DC CONVERTER AND CONTROL METHOD THEREOF - Disclosed is a small-size, high-efficiency, isolated, bidirectional DC-DC converter. The bidirectional DC-DC converter includes a transformer in which windings are magnetically coupled, switching circuits, a diode which is connected in parallel with a switch, smoothing capacitors, and a control section. First and second DC power supplies, which are connected in parallel with the smoothing capacitors, respectively, provide bidirectional electrical power transfer. When electrical power is to be transferred from the first DC power supply to the second DC power supply, the switch is maintained in the ON state. When, on the other hand, electrical power is to be transferred from the second DC power supply to the first DC power supply, the switch is maintained in the OFF state to prevent a reverse electrical power flow from the first DC power supply.03-04-2010

Hiroyuki Shoji, Kawasaki JP

Patent application numberDescriptionPublished
20080296746LEAD FRAME AND MANUFACTURING METHOD THEREOF, AND SEMICONDUCTOR APPARATUS AND MANUFACTURING METHOD THEREOF - The present invention includes a plurality of mounting portions on which a semiconductor element is mounted, a plurality of electrodes to which the semiconductor elements that are mounted on each of the mounting portions are electrically connected, a corner portion which connects the plurality of mounting portions and which has a hanging lead piece that supports the mounting portions and an electrode connection piece that connects the plurality of electrodes, and a half-blanking portion that has a concave portion formed in a thickness direction of the lead frame and a protrusion formed at a position corresponding to the concave portion, and which is covered with a sealing resin material that seals the semiconductor element. A stress-dispersing portion for dispersing stress that arises, when the half-blanking portion is formed, is provided in the corner portion.12-04-2008

Hiroyuki Shoji, Kanagawa JP

Patent application numberDescriptionPublished
20120032357SEMICONDUCTOR PACKAGE AND METHOD OF MANUFACTURING THE SAME - In a semiconductor package, a stamp is provided on at least one of at least a pair of opposed sides on an outer peripheral portion in contact with an edge of the package, which is a blank space up to now. With this configuration, the amount of stamp can be increased even in a narrow stamp area.02-09-2012

Hiroyuki Shoji, Tokyo JP

Patent application numberDescriptionPublished
20120098341BIDIRECTIONAL DC-DC CONVERTER AND CONTROL METHOD THEREOF - Disclosed is a small-size, high-efficiency, isolated, bidirectional DC-DC converter. The bidirectional DC-DC converter includes a transformer in which windings are magnetically coupled, switching circuits, a diode which is connected in parallel with a switch, smoothing capacitors, and a control section. First and second DC power supplies, which are connected in parallel with the smoothing capacitors, respectively, provide bidirectional electrical power transfer. When electrical power is to be transferred from the first DC power supply to the second DC power supply, the switch is maintained in the ON state. When, on the other hand, electrical power is to be transferred from the second DC power supply to the first DC power supply, the switch is maintained in the OFF state to prevent a reverse electrical power flow from the first DC power supply.04-26-2012