Denso Corporation

Kazuhiro Umetani

Fujiyuki Iwamoto

Akira Sakamoto

Satoshi Takeuchi

Yoshihide Itou

Keisuke Yagyu

Shuntaro Iguro

Naoya Kondou

A magnetic circuit component includes a magnetic core and a coil formed by winding a conductor around the magnetic core. The magnetic circuit component includes a magnetic material section that is formed from a soft magnetic material, and that covers a part of a surface of the coil or the entire surface of the coil and is disposed away from the magnetic core.

Magnetic circuit component

An induction heating apparatus includes: a core that has a pair of magnetic poles and transfers magnetic flux; a coil generating magnetic flux; conductors adjacently provided on both left and right sides of the magnetic poles; and lateral magnetic members formed of a magnetic material and arranged on an outer side of end portions of the object so as to extend along the end portions. The conductors shut off the magnetic flux that flows from a center portion of the heating object, taking a detour to the end portions, permit the magnetic flux to concentrate on the center portion, and accelerate temperature rise. The lateral magnetic members introduce the magnetic flux that propagates from one surface to the other surface, detouring around the end portions to thereby mitigate the magnetic flux density in the end portions and suppress overheating.

Induction heating apparatus

A detector includes a detection winding, a detection winding measurement section, and a detection section. A magnetic core has a hole penetrating the magnetic core along a non-uniform cross section. The detection winding includes a wire inserted into the hole and surrounding a periphery of a detection region that is a part of the non-uniform cross section and has a magnetic flux density different from an average magnetic flux density of the non-uniform cross section. The detection winding measurement section performs a measurement relating to an electromotive force induced by the detection winding. The detection section detects a magnetic bias, a magnetic saturation, or an amount of magnetic flux in the magnetic core based on a measurement result of the detection winding measurement section.

Detector of magnetic bias, magnetic saturation, or amount of magnetic flux

A resonant current limiting device, for a resonant current passage having a loop shape including at least one capacitor and a wiring passage with at least one inductor or inductance component, includes: an electric storage element connected in series with the capacitor; a driving power source; and a voltage controller that charges and discharges an electric charge in the electric storage element, which is supplied from the driving power source, controls a terminal voltage of the electric storage element to be a predetermined instruction voltage, and restricts a resonant current component flowing through the wiring passage.

Resonant current limiting device

In a current detection circuit, a first circuit is connected between a first terminal and a second terminal, and a second circuit is connected between a third terminal and a fourth terminal. The second terminal and the fourth terminal are commonly connected. When a first current flows between the first and second terminals, voltage drop occurs in the first circuit. A current control circuit controls the first current to make an application voltage between the first and second terminals substantially same as an application voltage between the third and fourth terminals. When the first circuit has voltage drop same as the second circuit, the first current has the amount proportional to the second current. A detection circuit detects a current flowing between the first terminal and the third terminal by detecting the first current controlled by the current control circuit or the second current.

Current detection circuit and semiconductor integrated circuit device

In a power conversion apparatus, a secondary winding is connected between main terminals of one of two circuit elements included in a main series circuit, and a voltage applied to a primary winding induces a voltage in a secondary winding in a direction from a first main terminal of a secondary winding, which is disposed at a low-potential side of the main series circuit, toward a second main terminal of a secondary winding, which is disposed at a high-potential side of the main series circuit. A rectifying unit blocks a current flowing from the high-potential side of the main series circuit toward the low-potential side of the main series circuit in a current path that includes the secondary winding and bypasses one of the two circuit elements included in the main series circuit.

Power conversion device

In a power converter, at least two main current paths each including an inductor and a transistor are connected between input terminals, and at least two storage circuits each including capacitors are correspondingly connected to branch nodes of the main current paths. Diodes are connected between the storage circuits. The transistors of the main current paths are interleaved. When one of the transistors is turned off, a current flowing in the corresponding inductor flows into the corresponding storage circuit to turn on the diodes and to charge the capacitors of the corresponding storage circuit. When another one of the transistors is turned off, a current flowing in the corresponding inductor flows into the corresponding storage circuit to turn on the diodes and charge the capacitors of the corresponding storage circuit.

Power converter

A series circuit of a diode Da, capacitors Ca, Caand a diode Dais connected in parallel to a series circuit of switching elements Sand S. A common junction between the capacitors Caand Cais connected to an emitter of the switching element S. A series circuit of a switching element Saand a diode Dais connected between a cathode of the diode Daand a cathode of the diode Da. A series circuit of a diode Daand a switching element Sais connected between an anode of the diode Daand the ground. A reactor Lais connected between a source of the switching element Saand a drain of the switching element Sa

Power converter with switched current supply control element

In a switching regulator, a control circuit includes a reference command value generation portion and an additional command value generation portion. The reference command value generation portion generates a reference command value based on a deviation of an output voltage from a predetermined command voltage. The additional command value generation portion generates an additional command value based on a difference between an outflow electric energy and an inflow electric energy. The outflow electric energy is a value reflecting a supply power from the capacitor to the load, and the inflow electric energy is a value reflecting a supply power from the reactor to the capacitor. The control circuit controls an operation ratio of a switching circuit based on the reference command value and the additional command value.

Switching regulator

An AC-DC converter includes two series circuits, an inductor, and a common snubber circuit. Each series circuit includes a switch and a current block device. The block device blocks a current from its high potential side to its low potential side when the first device is closed and allows the current from the low potential side to the high potential side when the first device is opened. The inductor is interposed between a first connection point between the switch and the block device of one series circuit and a second connection point between the switch and the block device of the other series circuit. The common snubber circuit is connected between each of the first connection point and the second connection point and at least one of both ends of the one series circuit.

AC-DC converter

A driver circuit for a semiconductor switching device includes a drive power source, a capacitor and four switches, which form a bridge circuit. The capacitor is provided between the four switches. In one cycle of application of a voltage to a gate of the semiconductor switching device to turn on the semiconductor switch, the first and the second switches, which are diagonal, are turned off and the third and the fourth switches, which are diagonal, are turned on to charge the capacitor. Then only the first switch is turned on to apply the voltage to the gate, and lastly only the second switch is turned on to discharge the capacitor thereby to apply a negative voltage to the gate of the semiconductor switching device.

Driver circuit having a storage device for driving switching device

A driving circuit that drives a semiconductor device includes first to sixth semiconductor devices. A first state and a second state are provided in one cycle in which a voltage is applied to a control terminal of the semiconductor device. In the first state, the first semiconductor device is closed, the third and fourth semiconductor devices are opened, and when the second semiconductor device is structured to have a semiconductor switch, the semiconductor switch is closed. In the second state, the first semiconductor device is opened, and the third and fourth semiconductor devices are closed.

Driving circuit

A power converter includes a main switch to which a capacitor is connected through a sub-diode. A series connection of a primary coil of a transformer and a sub-switch is connected parallel to the capacitor. A main diode is coupled in series with the main switch. A series connection of a sub-diode and a secondary coil of the transformer is parallel to the main diode. The rate of a rise in voltage across the main switch when turned off is suppressed by the rate of charging of the capacitor. Subsequently, by turning on the sub-switch, the current flowing through the main diode to be delivered to the transformer, thereby causing the current flowing through the main switch when turned on to be decreased by the sub-inductor.

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Nagoya, Japan

Kazuhiro Umetani