Matsushita Electric Industrial Co., Ltd.

Yoshihiro Takeshima

Koji Yoshida

Mitsuhiro Matsuo

Satoshi Ikeda

Hiroyuki Handa

A switching power supply comprises one or more switching sections which repeat ON/OFF operation, a transformer having a primary winding and a secondary winding, a synchronous rectifier section for rectifying a voltage induced in the secondary winding when an input voltage is applied to the primary winding of the transformer by the switching section, a smoothing section for smoothing the voltage rectified by the synchronous rectifier section to obtain an output voltage, a PWM control circuit which generates a PWM signal for adjusting the output voltage to determine an ON/OFF ratio of the switching section, and a drive transformer for ON-OFF driving the synchronous rectifier section according to the PWM signal, and is configured so as to use the energy stored in the drive transformer or the transformer for the ON/OFF operation of the synchronous rectifier section.

Switching power supply

Provided is a switching power supply unit which uses a multilayer board or a stack of planar conductors as the windings of transformers so as to reduce the volume of the transformers and to have high efficiency, small size and small noise. The switching power supply unit is formed by connecting a plurality of capacitors (), (), () and () connected in series with each other to input terminals () and () of a plurality of switching power supplies having switching elements (), (), () and (), transformers () and (), and rectifiers (), (), () and (). The switching power supply unit inputs the voltages of capacitors ()-(), and outputs the respective voltages developed by the plurality of switching power supplies together to common output terminals () and (). The transformers () and () are each composed of windings made up of a stack of planar conductor coils. This structure can reduce noise transmission through the windings, thereby providing stable output characteristics.

Switching power supply apparatus and electronic device using the same

A power module of the present invention mounts electronic components and comprises a circuit board that constitutes an electric power conversion circuit along with the above-mentioned electronic components; a heat sink; and a member with insulation characteristics and high thermal conductivity, which is disposed between plural devices with high heating value among the above-mentioned electronic components and the above-mentioned heat sink, embeds at least part of each of the above-mentioned plural devices with high heating value therein and transfers heat from the above-mentioned plural devices with high heating value to the above-mentioned heat sink.

Power module and production method thereof

A switching power supply device of the present invention comprises a transformer having at least a first primary coil, a first secondary coil, a second secondary coil, a second primary coil, and laminated in the sequence of the first primary coil, the first secondary coil, the second secondary coil, the second primary coil, and having a configuration wherein a center tap is drawn out from a connecting part between one end of said first secondary coil and one end of said second secondary coil; a switching part for alternately applying a voltage in a forward direction and an inverse direction to said transformer; a rectifying part for rectifying the voltage induced across the center tap of the transformer and the other end of the first secondary coil or the other end of the second secondary coil; a smoothing part for smoothing the voltage of the rectifying part; and a control part for controlling the on-off of the switching part so that the output voltage becomes stable.

Switching power supply device

A switching power supply device of the invention includes: a switching circuit for interrupting direct current to generate a pulse voltage; a transformer including a primary winding, a secondary winding, and a core for magnetically coupling the primary winding and the secondary winding; a multi-layer wiring board having wiring lines constituting the primary winding and the secondary winding; a rectifier circuit for rectifying an alternating current; a smoothing circuit for suppressing ripple; and a control circuit for controlling an output voltage from the smoothing circuit. The multi-layer wiring board is provided with at least the switching circuit and the rectifier circuit and is arranged on a main wiring board, and the control circuit is arranged on the main wiring board.

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Nara, Japan

Yoshihiro Takeshima