Murata Manufacturing Co., Ltd.

Takashi Kurokawa

Koji Nishi

Soichi Watanabe

A magnetic-field generating circuit includes a transformer antenna that includes a transformer including a primary coil and a secondary coil and a resonant capacitor connected in parallel to the secondary coil of the transformer and that generates a magnetic field. Moreover, an AC power supply circuit is provided that supplies an AC voltage serving as a driving voltage to the primary coil of the transformer antenna. The secondary coil and the resonant capacitor form a parallel resonant circuit whose resonant frequency is set to be equal to a frequency of the AC voltage supplied from the AC power supply circuit.

Magnetic-field generating circuit

An antenna device includes a magnetic core having first and second main surfaces and extending in a first direction, and planar first and second coils connected in series and disposed next to each other in the first direction. The first coil has a first portion located on a side of the first main surface and a second portion located on a side of the second main surface and not overlapping the first portion in a plan view. The second coil has a third portion located on the side of the first main surface and a fourth portion located on the side of the second main surface and disposed at a position that does not overlap the third portion in the plan view. The shortest distance between the second and fourth portions is shorter than the shortest distance between the second and third portions.

Antenna device and multiaxial antenna device including antenna device

A power supply unit includes a transformer including a primary winding that receives an alternating-current voltage and a secondary winding including a first end electrically connected to ground, a positive-side rectification circuit including a diode electrically connected to a second end of the secondary winding, an anode of which is electrically connected to the second end, and a cathode of which is electrically connected to a positive-side output terminal, a negative-side rectification circuit including a diode electrically connected to the second end of the secondary winding, a cathode of which is electrically connected to the second end, and an anode of which is electrically connected to a negative-side output terminal, and a capacitor provided on a path from a node between the second end of the secondary winding and the positive-side rectification circuit and the negative-side rectification circuit to the ground through the secondary winding.

Power supply unit and static eliminator

A transformer that is capable of setting any characteristics of a detection voltage of a detection winding and accurately detecting an output voltage includes a bobbin, a magnetic core, a first input winding, an output winding, a second input winding, and a detection winding. The bobbin is tubular and includes a plurality of winding regions located at its outer portion. The magnetic core is inserted in the bobbin. The first input winding is wound in a first winding region. The output winding is wound in a second winding region adjacent to the first winding region. The second input winding is wound in a third winding region adjacent to the second winding region. The detection winding is wound in the vicinity of the first input winding. The first input winding and the second input winding have different numbers of turns and are connected in series in the same winding direction.

Transformer and transformer device

In a power supply apparatus, in a standby mode, control signals for controlling a first MOSFET of a power supply apparatus to be turned on and a second MOSFET to be turned off are supplied to the gates of the first and second MOSFETs from a control circuit, respectively. The emitter of a PNP transistor is connected to the gate of the second MOSFET through a diode of a switch circuit and the collector is connected to the ground. A power supply operation control signal is input to the base of the PNP transistor. When a power supply operation control signal in a Low state is input to the base in a standby mode, the emitter and the collector are connected to each other. Accordingly, the gate of the second MOSFET has a potential substantially the same as a ground potential and the second MOSFET is turned off irrespective of the control signal.

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Nagaokakyo, Japan

Takashi Kurokawa