Tdk Corporation

Wataru Nakahori

Haruhiko Sanae

Yasuhiro Hara

Masaki Sato

Hiroshi Miyazaki

Masaki Kan

Yasuhiro Murai

Shinya Ofuji

Atsushi Yakuwa

Torao Misono

A switching power supply unit includes an N-number (N: an integer of 2 or greater) of transformers; an N-number of inverter circuits; a rectifying smoothing circuit including a {2&#xd7;(N+1)}-number of rectifying devices, a choke coil, and a capacitor; an additional winding disposed to be interlinked with each of magnetic paths formed in the N-number of transformers; and a driver. In the rectifying smoothing circuit, a (N+1)-number of arms each have two of the rectifying devices, and are disposed in parallel to one another between the pair of output terminals, a secondary winding in each of the N-number of transformers is coupled between adjacent ones of the (N+1)-number of arms to individually form an H-bridge coupling, and the additional winding is coupled in series to one or more of the secondary windings in the N-number of transformers.

Switching power supply unit

A switching power supply unit includes input terminals, output terminals, first to third primary windings and first to third secondary windings, a switching circuit, a rectifying smoothing circuit, and a driver. In the switching circuit, first and second switching devices, third and fourth switching devices, and first and second capacitors, coupled in series to one another, are disposed in parallel between the input terminals. In the rectifying smoothing circuit, first to third arms, each having two of rectifying devices disposed in series, are disposed in parallel between the output terminals, the first secondary winding is coupled between the first and the second arms to form an H-bridge coupling, the second and the third secondary windings are coupled between the second and the third arms to form an H-bridge coupling, and a choke coil is disposed between the first to the third arms and an output capacitor.

Provided is a switching power supply unit that includes a pair of input terminals, a pair of output terminals, two transformers, two inverter circuits, a rectifying smoothing circuit, and a driver. The rectifying smoothing circuit includes eight rectifying devices, a first choke coil, a second choke coil, and a capacitance. In the rectifying smoothing circuit, two full-bridge rectifying circuits are provided that each include a first arm and a second arm. The first arm and the second arm each have two of the eight rectifying devices. Secondary windings of the respective two transformers are each coupled to corresponding one of the two full-bridge rectifying circuits to form an H-bridge coupling. Coupling relation of the first arm, the second arm, the first choke coil, the second choke coil, and the capacitance is appropriately defined.

In a power supply device, a first space Rand a second space Rare delimited, a coil componentis arranged in the first space R, and heat-generating components and components having weak resistance to heat are arranged in the second space R. The power supply deviceis configured to contain the coil componentin the first space Rso that ambient air of the coil componentcan contact a first side wall, which constitutes the first space R, making it possible to expect discharge of heat to coolant in a coolant channel W via the first side wall. Therefore, heat can be discharged from the ambient air of the coil component, the temperature of which has been raised by heat generation, towards the coolant efficiently.

Power supply device

In the coil unitA of the power supply device, the U-shaped plateC constituting the U-shaped terminalis used to electrically connect the print-coil substrates. Further, the print-coil substratesconstituting the coil unitA can be connected to the main circuit substratealso by using the U-shaped terminal. Here, the print-coil substrateis connected to the print-coil substrateby using the U-shaped terminal, by which soldering for fixing the U-shaped terminalis performed from the lower face side of the print-coil substrate. Therefore, as compared with a conventional constitution where soldering is performed from both sides of the stacked print-coil substrates, the print coils can be connected by soldering only from one side face, thus making it possible to reduce the amount of work necessary for connecting the print coils.

Coil unit, substrate unit and power supply device

The switching power supply unit includes: a transformer having a primary winding and two secondary windings; and a rectifying-smoothing circuit having two rectifying elements, three choke coils and a capacitive element. A first rectifying element is between a junction of ends of the first secondary winding and the second choke coil, and one end of the capacitive element. A second rectifying element is between a junction of ends of the second secondary winding and the third choke coil, and the one end of the capacitive element. The other end of the first secondary winding and the other end of second secondary winding are connected to the one end of the first choke coil. The other end of the first choke coil, the other end of the second choke coil, and the other end of the third choke coil are connected to the other end of the capacitive element.

A switching power supply includes: a transformer including primary and secondary windings; a switching circuit including first and second switching elements, first and second rectifying elements, first and second capacitive elements and a first inductor; and a rectifying/smoothing circuit. A first bridge circuit is configured by the first and second switching elements located in a diagonal arrangement and the first and second capacitive elements also located in a diagonal arrangement. The first and second rectifying elements are connected in parallel to the first and second switching elements, respectively. One of the first and second rectifying elements is in forward direction and other is in inverse direction. The first inductor is disposed on a connection line between the pair of input terminals and the first bridge circuit. The primary winding is connected to the first bridge circuit to form a H-bridge configuration. The secondary winding is disposed in the rectifying/smoothing circuit.

Switching power supply

A coil substrate structure which enhances heat dissipation and fully secures a mounting area is provided. A coil substrate structurecomprises a first coil substratehaving a primary transformer coil part; a second coil substrate, disposed on the first coil substrate, having a secondary transformer coil part; and a transformer corefor magnetically connecting the transformer coil partsto each other. The coil substratesare disposed on each other while being shifted from each other such that the transformer coil partsoverlap each other as seen in the substrate thickness direction. This can increase the heat dissipation area of the coil substrates. The transformer coil partshave a width in a transmission direction A narrower than a width in a direction B intersecting the transmission direction A as seen in the substrate thickness direction. This can reduce the multilayer area of the coil substratesin the transmission direction A.

Coil substrate structure, substrate holding structure, and switching power supply

The transformer includes: a magnetic core having two base-plates and four legs; a first conductive member as a first winding, having four through-holes through which the four legs pass, respectively; and one or more second conductive members as a second winding, each having four through-holes through which the four legs pass, respectively. The first and second windings are wound around the four legs. Closed magnetic paths are formed inside the magnetic core from the four legs to the two base-plates due to currents flowing through the first or the second winding. A couple of magnetic fluxes each generated inside each of a couple of legs arranged along one diagonal line are both directed in a first direction, while another couple of magnetic fluxes each generated inside each of another couple of legs arranged along another diagonal line are both directed in a second direction opposite to the first direction.

Transformer and switching power supply unit

This switching power supply provides a stable output. In the switching power supply, at least pairs of secondary side coils are connected to each of the center tap rectifier circuits and the secondary side coils of each of the center tap rectifier circuits are disposed in the core portions (cores) of mutually different transformers.

Stable output in a switching power supply by smoothing the output of the secondary coil

The first choke coil and the third choke coil are not magnetically coupled to the second choke coil and the fourth choke coil. Therefore, even in a case where a structure for increasing the heat radiation area is adopted, a pair of the first and third choke coils and a pair of the second and fourth choke coils located between the two ends of the capacitor maintain a state of equilibrium so as to be inversely proportional to mutual loss without affecting one another, and the output therefore stabilizes. Accordingly, the output of the switching power supply, that is, the rectified and smoothed output across the two ends of the capacitor stabilizes.

Switching power supply with smoothing circuitry for more stable output

Primary and secondary coils are provided in the first through section and a coil group is also provided in the second through section. Hence, the surface area over which the coil group extends within a plane which is perpendicular to the through sections is greater than in the case where all of the coils are provided in a single through section. The surface area which is not covered by the magnetic body cores of the platelike members increases. In cases where the surface area of the members is large, the heat radiation characteristic is enhanced. Hence, the cooling efficiency of the transformer improves. In cases where there is a plurality of coil groups which are magnetically coupled to one another in particular, because it is difficult to move the heat produced in the plurality of coil groups through heat conduction, heat transfer, or heat radiation, a heat radiation structure of this kind is effective.

DC/DC converter

A switching power supply unit is provided, which may supply stable output while manufacturing cost is held down. In a smoothing circuit, a magnetic flux in a first circular magnetic path, a magnetic flux in a second circular magnetic path, a magnetic flux generated by a current flowing through a choke coil, and a magnetic flux generated by a current flowing through another choke coil are shared by one another in the inside of a common magnetic core. A current flowing through two choke coils and a current flowing through different, two choke coils are balanced, and thus stabilized. Moreover, in the smoothing circuit, since such a balanced state is automatically kept, a characteristic value of an element or the like need not be adjusted.

A witching power supply unit, which suppresses switching loss in switching elements and surge voltage onto an output rectifier device and reduces the number of components, is provided. The switching power supply unit include: a switching circuit of full bridge type disposed on the input side; a rectifier circuit disposed on the output side; a transformer disposed between the switching circuit and the rectifier circuit and including a first winding on the input side, a second winding on the output side, a third winding; a surge voltage suppressing circuit connected in parallel with the switching circuit; and a driving circuit. The third winding is connected to the full bridge circuit to form a H-bridge configuration. Magnetic coupling between the first and second windings and magnetic coupling between the first and third windings are both looser than that between the second and third windings.

According to the switching supply such as a DC/DC converter, since primary side coils provided in two transformers are mutually connected in series, voltage variation generated in parallel-connected secondary side coils can be suppressed, and the uniformity of secondary side parallel output can be enhanced even in case of voltage value fluctuations or the like caused by variation in the output of an inverter circuit.

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Tokyo, Japan

Wataru Nakahori