JP2011045196A - One side mounting type dc stabilized power supply - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a one side mounting type DC stabilized power supply in which all components constituting the power supply including a transformer are surface-mounted only on one face of a printed board. <P>SOLUTION: A printed wiring pattern for connecting a plurality of circuit structure components including the transformer constituting the power supply are formed only on one face of the board. All the circuit structure components are surface-mounted only on one face of the board where the printed wiring pattern is formed. The power supply is constituted in a state where circuit structure members on the DC stabilized power supply are collected only on one face of the printed board, and the circuit structure members are not arranged on the other face. Thus, the radiation property of heat generated in the power supply can easily be secured. Since no dedicated radiation member is necessary to be combined and mounted on the transformer, surface mounting of the transformer, which cannot be performed in a conventional case, is realized and the miniaturized/thinned DC stabilized power supply for AC power supply can be supplied. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a stabilized DC power supply for an AC power supply (for AC input) that generates a stable DC voltage (or current) that is not affected by input fluctuations or load fluctuations using an AC power supply. In particular, the present invention relates to a single-sided direct current stabilized power source in which all of a large number of electronic components including a transformer constituting the power source are surface-mounted only on one side of a printed circuit board.

  For example, home appliances and information devices such as televisions and personal computers using commercial AC power supplies (AC100V, etc.) operate with a DC power supply (DC voltage or current) such as a microcomputer (IC) for controlling them. Built-in electronic devices. Since these electronic devices operated by a DC power source do not operate well if an AC voltage (or current, the same applies hereinafter) input by an AC power source is used as it is, the input AC voltage is not at the level of a battery such as a dry cell. Conversion to a low DC voltage is performed by a DC stabilized power supply. Conventionally known DC stabilized power supplies for AC power supplies (for AC input) can be included in a plurality of circuits constituting the power supply, for example, input noise filters (line filters, etc.), resistors, capacitors, power transformers, inductors, etc. A large number of circuit components such as electronic components and electronic elements (hereinafter simply referred to as components) are arranged at appropriate positions on a printed circuit board. Built in products and information devices.

  Here, a conventional DC stabilized power supply for an AC power supply is shown in FIG. FIG. 7 is a conceptual diagram showing a part of a conventionally known DC stabilized power supply for an AC power supply. 7A is a top view of a conventional DC stabilized power supply viewed from the top, FIG. 7B is a side view of the conventional DC stabilized power supply viewed from the side, and FIG. 7C is a conventional DC stabilized power supply. It is the bottom view which looked at the control power supply from the bottom.

  As shown in FIG. 7C, in the known DC stabilized power supply for an AC power supply, a plurality of circuits (for example, an input noise filter circuit) constituting the DC stabilized power supply on the bottom surface side of the printed circuit board 1 are provided. , A rectifying / smoothing circuit, a DC-DC converter circuit, a control circuit, etc.) are formed by printing a copper foil or the like, and as shown in FIGS. 7A and 7B In addition, a switching element S, a capacitor C, a power supply transformer T, a line filter LF, and a resistor R with respect to a through hole H (so-called through hole) penetrating the printed circuit board 1 provided at a predetermined position of the circuit wiring pattern CP. The upper surface of the printed circuit board 1 is soldered to each component such as an inductor (not shown) and a pin terminal D made of a lead wire for each component. It has to be attached to the (part mounting surface). As can be understood from FIG. 7B, in some cases, a component (referred to as a bottom-mounted component) may be attached to the bottom surface side of the printed circuit board 1. As an example of mounting each component only on one side of the printed circuit board 1 by soldering the pin terminals D as described above, for example, one described in Patent Document 1 can be cited.

  Recently, household appliances have been made smaller and thinner as represented by televisions, etc. In addition to this, in addition to lowering the voltage and increasing the current for the DC-stabilized power supply built into them, There is a demand for a small and thin power source that can be installed anywhere. As one method for realizing a thinner DC stabilized power supply, it is conceivable to adopt a configuration in which each component to be mounted on the printed circuit board is made as thin as possible (that is, low profile). Even if the components are made thin and low-profile, each component is attached to the bottom surface of the printed circuit board as shown in FIG. The lead portion was a factor that hindered thinning.

  That is, when a conventionally known DC stabilized power supply as shown in FIG. 7 is actually attached to a device such as a home appliance, the material of the device housing close to the bottom surface of the printed circuit board 1 is a conductive material such as a metal. If there is, there is a risk of causing an electric shock or electric leakage, and as a safety measure to prevent it, the terminal portion of the pin terminal D that protrudes to the bottom side is printed so that it does not come into contact with the device housing 3. A sufficient space must be secured between the substrate 1 (specifically, the end of the pin terminal D) and the housing 3, or between the printed circuit board 1 (specifically, the end of the pin terminal D) and the housing 3. An insulator such as the insulating sheet 2 must be added separately (see FIG. 7B). Ensuring such insulation can be a factor that hinders the thickness reduction of the DC stabilized power supply. From the above, the DC stability is maintained while adopting the so-called pin insertion method in which components are attached to the through holes H provided in the printed circuit board 1 through the pin terminals D and the like as shown in Patent Document 1 and FIG. It will be understood that it is very difficult to reduce the size / thinning of the power source.

  By the way, in general, as a technique for attaching components to the printed circuit board 1, components are mounted on the surface of the printed circuit board without providing through holes H (through holes) in the printed circuit board 1 (however, mounted on the printed circuit board 1 by surface mounting technology). There is known a surface mounting technology capable of attaching a possible surface mounting component). Therefore, it is conceivable to adopt the surface mounting technique as another method for realizing the downsizing / thinning of the stabilized DC power supply.

  However, in a DC stabilized power supply (so-called AC-DC converter) for an AC power supply that uses a commercial AC power supply to generate a stable DC voltage (or current) that is not affected by input fluctuations or load fluctuations, particularly in terms of safety and noise In the past, it was impossible to adopt the surface mounting technology because of the possibility of problems. Specifically, it is a surface mount type that does not have a thin (low profile) line filter LF, and is also a surface mount type that is thin (low profile) that can secure a large output capacity. It was difficult to attach a metal for heat dissipation (a so-called heat dissipation member such as a heat sink) or the like to each component that did not have a power supply transformer T, and that would easily generate heat as the DC stabilized power supply itself was made thinner. There was a problem. For this reason, a DC stabilized power supply for an AC power supply that has been downsized / thinned using the surface mounting technology has been conventionally desired, but such a power supply has not been proposed yet.

  On the other hand, in Patent Document 2 below, it is shown that circuit components constituting a part of a module of a power supply circuit are surface-mounted on both surfaces of a circuit board. However, in Patent Document 2, only a part of the power supply modules are surface-mounted on both sides of the circuit board, and the entire circuit components of the power supply device including large and heat-generating parts such as transformers are arranged. Surface mounting is not shown. As described above, a component having a large calorific value such as a transformer needs to be mounted in combination with a heat radiating member, and thus has not been considered suitable for surface mounting.

Japanese Patent Laid-Open No. 2001-44620 JP 2000-357866 JP

  The present invention has been made in view of the above points, and is a direct current stabilized power supply for an alternating current power supply, in which all the components constituting the power supply including a transformer are surface-mounted only on one side of a printed circuit board. An object is to provide a direct current stabilized power supply of the type.

  A single-sided stabilized DC power supply according to the present invention is a DC stabilized power supply for an AC power supply that performs AC / DC conversion, and connects a plurality of circuit components including a transformer to each of the circuit components. A printed circuit board in which a printed wiring pattern is formed only on one side of the board, and all of the plurality of circuit components are surface-mounted only on one side of the board on which the printed wiring pattern is formed. It is characterized by that.

  According to the present invention, a printed wiring pattern for connecting a plurality of circuit components including a transformer constituting the DC stabilized power supply is formed only on one surface of the substrate, and all of the plurality of circuit components are printed on the printed circuit board. Surface mounting was performed only on one side of the substrate on which the wiring pattern was formed. According to this, the circuit components related to the DC stabilized power supply are collected only on one side (front surface) of the printed circuit board, and the power supply is in a state where no such circuit components are arranged on the other side (back surface). Can be configured. In addition, since the circuit component is mounted by the surface mounting technology, the terminal connecting the component and the circuit wiring pattern does not appear on the back surface. Therefore, the power supply can be mounted directly in contact with the housing of the home appliance or information device to which it is attached without securing an interval from the housing or sandwiching an insulator between the housing. Thus, it is possible to easily secure the heat dissipation of the heat generated by the power source by the heat conduction to the housing of the attachment destination. In particular, since it is not necessary to mount a dedicated heat dissipating member in combination in the transformer, it is possible to provide a stabilized DC power supply for an AC power supply that realizes surface mounting of the transformer that has not been conventionally achieved.

  As a preferred embodiment of the present invention, it further includes an attachment member for attaching the printed circuit board, the transformer does not include a dedicated heat dissipation member, and one side of the substrate on which the printed wiring pattern is formed; Is arranged so that the surface of the printed circuit board on the opposite side is in contact with the mounting member, and heat generated from the transformer is radiated through the mounting member. Thus, by realizing heat dissipation through the mounting member, it is possible to ensure heat dissipation without attaching a dedicated heat dissipation member to the transformer. This realizes the surface mounting of the transformer, thereby greatly contributing to the downsizing / thinning of the stabilized DC power supply for the AC power supply. Needless to say, realizing heat dissipation through the attachment member does not prevent the transformer from being attached with a light heat dissipation member.

  According to the present invention, the circuit wiring pattern is formed only on one side of the printed circuit board, and all the circuit components including the transformer constituting the power supply are surface-mounted only on the one side where the circuit wiring pattern is formed. Since it did in this way, it can be made easy to dissipate the heat which can be generated with the said power supply by having the other surface in which such a circuit component is not arrange | positioned at all. This makes it possible to mount the parts on the surface of a heat generating member such as a transformer that had to be mounted in combination with a heat radiating member in the past without attaching a heat radiating member that promotes heat dissipation. As a result, it is possible to reduce the size and thickness of the stabilized DC power supply for the AC power supply.

BRIEF DESCRIPTION OF THE DRAWINGS It is a conceptual diagram which shows one Example of the whole structure of the single-sided mounting type DC stabilized power supply based on this invention, Comprising: Fig.1 (a) is a top view, FIG.1 (b) is a side view, FIG.1 (c). Is a bottom view. FIG. 2 is a circuit diagram showing an embodiment of an equivalent circuit of the DC stabilized power supply shown in FIG. 1. FIG. 3A is a conceptual diagram illustrating an example of the overall configuration of a surface mount line filter used in the present DC stabilized power supply, FIG. 3A is an exploded perspective view, and FIG. 3B is a side sectional view. . The voltage / current change when the MOS transistor, which is a switching element included in the rectifying and smoothing circuit, is switched on / off is shown. FIG. 5A is a conceptual diagram illustrating an example of the overall configuration of a surface-mount power transformer used in the present DC stabilized power supply, FIG. 5A is an exploded perspective view, and FIG. 5B is a side sectional view. . It is a side view which shows the state which attached this direct current | flow stabilized power supply to the attachment member. FIGS. 7A and 7B are conceptual diagrams showing a part of a conventionally known stabilized DC power supply for an AC power supply, in which FIG. 7A is a top view, FIG. 7B is a side view, and FIG. 7C is a bottom view. is there.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a conceptual diagram showing an embodiment of the overall configuration of a single-sided mounting type stabilized DC power supply according to the present invention. 1A is a top view of the DC stabilized power source as viewed from above, FIG. 1B is a side view of the DC stabilized power source as viewed from the side, and FIG. 1C is the DC stabilized power source. It is the bottom view seen from the bottom. FIG. 2 is a circuit diagram showing an embodiment of an equivalent circuit of the stabilized DC power supply shown in FIG. However, here, a switching regulated DC stabilized power supply, a so-called switching regulator is shown as an example. In FIG. 1B, some components are not shown, and in FIG. 2, the illustration of a resonant inductor LP3 (see FIG. 5 described later) wound together with the primary winding LP1 of the power transformer T is omitted. ing.

  The DC stabilized power source shown in the present embodiment converts an AC voltage (AC 100 V) supplied from a commercial power source (not shown) into a low DC voltage (or current), as can be understood from FIG. One to a plurality of circuits included in a plurality of circuits (input noise filter circuit S1, rectifying / smoothing circuit S2, DC-DC converter circuit S3 (DC conversion circuit), control circuit S4, etc., refer to FIG. 2) forming this power supply The components (for example, MOS transistor S, capacitor C, power transformer T, line filter LF, resistor R, inductor L, etc.) are all surface-mounted only on one side (front side) of the printed circuit board 1. In addition, as shown in FIG. 1, components (heat generating components) that generate heat in accordance with the electrical operation of the power transformer T or the like are not combined with a dedicated heat radiating member (for example, a heat sink), so Only is surface mounted on the printed circuit board 1.

  The printed circuit board 1 does not have a through hole H (through hole) penetrating the printed circuit board 1 as shown in the conventional example of FIG. 7, and each component is mounted on the surface of the printed circuit board 1 according to the surface mounting technology. It is comprised so that. However, each of the components is a low-profile component having a lead terminal E having a shape suitable for being mounted on the surface of the printed circuit board 1 by surface mounting technology, as shown in FIG. The lead terminals E are mounted only on the front surface side of the printed circuit board 1 so that the lead terminals E do not appear on the bottom surface side of the printed circuit board 1. A detailed description of such surface mount components will be described later (see FIG. 3 or FIG. 5 described later).

  Further, not only the above components are mounted on the component mounting surface side (front surface side) of the printed circuit board 1, but also a plurality of circuits constituting the direct current stabilized power source as shown in FIG. An input noise filter circuit S1 including at least a line filter LF for removing common mode noise that can be generated in the rectifier, rectifies the input alternating current to be converted into direct current, and rectifies to smooth the output after conversion Circuit wiring formed by combining various circuits such as a smoothing circuit S2, a DC-DC converter circuit S3 (DC conversion circuit) for obtaining a DC output having a desired magnitude, and a control circuit S4 for variably controlling the DC output voltage. The pattern CP is formed by printing a copper foil or the like. On the other hand, as shown in FIG. 1C, the circuit wiring pattern CP is not formed on the bottom surface side of the printed board 1. Since the conversion operation for obtaining the direct current output from the alternating current input using each of the circuits S1 to S4 is well known, detailed description thereof is omitted here.

  In the embodiment shown here, the switching element of the rectifying / smoothing circuit S2 is composed of the MOS transistor S. However, the present invention is not limited to this, and other electronic elements such as a bipolar transistor and IGBT are used as the switching element. Needless to say, it can be used. Further, the switching element may be configured by combining two or more transistors as described above.

  As described above, in the direct current stabilized power supply shown in the present embodiment, a large number of components included in the circuits S1 to S4 that are surface-mounted on the printed circuit board 1 can be mounted on the printed circuit board 1 by surface mounting technology. It is a component for mounting. Since MOS transistors S, capacitors C, resistors R, inductors L and the like may be made of conventionally known surface mounting components, description thereof will be omitted. On the other hand, among surface mounting components that are surface mounted on the printed circuit board 1 by surface mounting technology, the line filter LF included in the input noise filter circuit S1 and the power transformer T included in the DC-DC converter circuit S3 have been conventionally used. There was no particular configuration suitable for surface mounting. In view of this, in the DC stabilized power supply according to the present invention, a line filter LF and a power transformer T having a configuration suitable for surface mounting are newly employed.

  First, the surface mount line filter LF included in the input noise filter circuit S1 will be described. FIG. 3 is a conceptual diagram showing an example of the overall configuration of a surface mount line filter used in the present DC stabilized power supply. 3A is an exploded perspective view, and FIG. 3B is a side sectional view.

  As shown in FIG. 3A, the surface mount line filter LF includes a bobbin B made of an insulating material (phenol or the like) and a set of drum cores F made of a magnetic material (ferrite or the like). . The bobbin B has a substantially I-shape having a cylindrical core portion Ba having a uniform outer diameter and jaw portions Bb projecting from both ends of the core portion Ba in the radial direction of each core portion Ba. It is formed into a shape. Two windings LP1 (primary side) and LP4 (secondary side) formed by coating a conductor wire such as a copper wire with a three-layer insulating coating film on the outer periphery of the winding core portion Ba are so-called. The winding is wound by bifilar winding (that is, two windings LP1 and LP4 are wound around the outer periphery of the winding core portion Ba).

  A plurality of lead terminals E that are suitable for surface mounting are implanted in the lower part of the jaw Bb instead of pin terminals made of lead wires (see FIG. 7), and some of them are here. On the other hand, the respective ends of the windings LP1 and LP4 wound around the winding core Ba are connected. Here, the ends of the windings LP1 and LP4 are connected to only the two lead terminals E, and nothing is connected to the other lead terminals E.

  Further, the bobbin B is provided with an opening Bc in the vicinity of the center of the jaw Bb formed at both ends of the core Ba as shown in the figure, and further from there to the inside of the core Ba. Is formed. The sizes of the opening Bc and the cavity are such that at least the core portion Fa (magnetic core) of the drum core F can be fitted.

  The drum core F is formed in a substantially E shape by a magnetic material (ferrite or the like), and two (one pair) are formed by fitting the core portion Fa formed in the center portion into the opening Bc of the bobbin B. And the bobbin B is sandwiched between the drum cores F). Thus, by attaching each core part Fa of the pair of drum cores F so as to enter the inside of the core part Ba of the bobbin B, each core part Fa has two windings wound around the core part Ba. The magnetic cores of the lines LP1 and LP4 are configured. When a pair of drum cores F are attached to one bobbin B, a spacer (not shown) is inserted between each core part Fa and the core part Fa, thereby adjusting the gap between the magnetic cores. Inductance can be adjusted.

As shown in FIG. 3B, after attaching a pair of drum cores F to one bobbin B, the attached drum cores F are wound by winding an insulator such as an insulating tape Z along the outer periphery of the drum core F. Needless to say, it should be fixed so as not to be separated from the bobbin B. Alternatively, the winding may be stopped by winding an insulator so as to cover the two windings LP1 and LP4 wound around the winding core portion Ba.
The shape of the drum core F described above is an example, and is not limited to this.

  Here, when the line filter LF is configured as described above and is a surface-mountable component, the noise characteristics are experimentally inferior to those of the conventional pin terminal D (not for surface mounting). all right. Specifically, as shown in FIG. 4B, a large noise inevitably occurs at the rise of the DC voltage Vds (see FIG. 2) applied to the MOS transistor S included in the rectifying and smoothing circuit S2. Then, when the MOS transistor S is switched on, a sudden current change as indicated by the arrow Y is caused in the direct current Id (see FIG. 2) flowing into the MOS transistor S, so it is desired to remove the noise as much as possible.

  Therefore, in the stabilized DC power supply according to the present invention, as shown in FIG. 2, a capacitor CK (so-called resonant capacitor) is connected in parallel to the MOS transistor S for noise removal, and the capacitor CK is connected to the DC-DC converter. A partial resonance circuit is configured by combining with a resonance inductor LP3 (described later) included in the circuit S3. In this way, even if a large noise is applied to the rise of the DC voltage Vds applied to the MOS transistor S, when the capacitor CK is not provided, the DC current is turned on when the MOS transistor S is switched on as indicated by the arrow Y. In the case where Id showed a sudden change in current (see FIG. 4B), the provision of the capacitor CK eliminates the direct current Id from showing a sudden change when the MOS transistor S is switched on. Change (see FIG. 4A). By doing so, the supply of the direct current Id to the primary winding LP1 of the power transformer T included in the DC-DC converter circuit S3 can be controlled without causing a sudden change.

  Next, a power supply transformer T for surface mounting included in the DC-DC converter circuit S3 (DC conversion circuit) will be described. FIG. 5 is a conceptual diagram showing an example of the overall configuration of a surface-mount power transformer used in the present DC stabilized power supply. FIG. 5A is an exploded perspective view, and FIG. 5B is a side sectional view.

  As shown in FIG. 5, the surface-mount power transformer T has almost the same configuration as the above-described surface-mount line filter LF, that is, a bobbin B made of an insulating material (phenol or the like) and a magnetic material (ferrite or the like). And a set of drum cores F. To reiterate, the bobbin B has a cylindrical core portion Ba having a uniform outer diameter and is protruded in the radial direction of each core portion Ba from both ends of the core portion Ba. It is formed in a substantially I shape having a jaw part Bb. A plurality of lead terminals E made of terminal pins having a shape suitable for surface mounting are planted on the jaw Bb (here, five), and a plurality of lead terminals E are provided on the core Ba for some of them. The respective ends of a plurality of windings LP1 to LP4 (details will be described later) wound separately in the respective winding layers are connected. However, in FIG. 5A, only the winding LP1 constituting the innermost (first layer) winding layer is shown for convenience in order to facilitate understanding of the description.

  The bobbin B is provided with an opening Bc in the vicinity of the center of the jaw Bb formed at both ends of the core Ba as shown in the figure, and a cavity is formed from there to the inside of the core Ba. ing. The size of the opening Bc and the cavity is such that at least the core portion Fa (magnetic core) provided at the center of the drum core F can be fitted. On the other hand, the drum core F is formed in a substantially E shape with a magnetic material (ferrite or the like) material. By fitting the core portion Fa into the opening Bc, two (one pair) of drum cores F can be used. The bobbin B can be attached so as to sandwich it. That is, the core portion Fa of the pair of drum cores F forms a magnetic core of a plurality of windings LP1 to LP4 wound around the winding core portion Ba. Of course, by inserting a spacer (not shown) between the core part Fa and the core part Fa of the drum core F, it is possible to adjust the gap of the magnetic core, that is, to adjust the inductance.

  In the power transformer T described above, as shown in FIG. 5 (b), a plurality of windings LP1 to LP4 formed by coating a conductor wire such as a copper wire with an insulating coating film on the outer periphery of the winding core portion Ba. Are wound respectively. The plurality of windings LP1 to LP4 are divided into four winding layers that overlap each other between the jaw portions Bb of the bobbin B in the radial direction of the winding core portion Ba, and the primary winding LP1 and the feedback winding LP2. , A resonance inductor LP3 for partial resonance, and a secondary winding LP4. Here, the primary winding LP1 constitutes the innermost (first layer) winding layer, the secondary winding LP4 constitutes the second (second layer) winding layer from the inside, and the resonant inductor LP3. Constitutes the third (third layer) winding layer from the inside, and the feedback winding LP2 constitutes the fourth (fourth layer) winding layer from the inside. The insulation distance between the windings LP1 to LP4 is ensured to an extent required by law by the interlayer tape M disposed between the windings made of an insulating material.

  Further, as shown in FIG. 5B, for example, a step N is formed of the same material as the molding material of the bobbin B on both sides of the bobbin B winding frame, or an insulating tape having an insulating property is wound. It is preferable to secure the creepage distance of the winding by providing the step N.

  By the way, considering that the power transformer T must ensure heat generation and insulation, it is originally required to use a large bobbin B. If a large bobbin B is used, it is easy to ensure heat generation and insulation. However, in order to make the power transformer T smaller / thinner, it is necessary to make the bobbin B itself smaller / thinner. Therefore, heat generation and insulation must be secured after the bobbin B is downsized / thinned. Therefore, in this power transformer T, since insulation is ensured by the interlayer tape as described above, in order to make it easy to ensure insulation by such an interlayer tape, a copper wire (0.12- 0.16mm) is used for the winding.

  When such a thin winding with a small diameter is wound many times, heat is likely to be generated. However, as already described in the DC stabilized power supply in this embodiment, the components included in each circuit constituting the power supply Since all of the above can be surface-mounted only on one side of the printed circuit board 1, the bottom surface side of the printed circuit board 1 can be made almost flat with nothing (see FIG. 1C). If so, for example, as shown in FIG. 6, the power supply is attached to the attachment member U with good heat conduction efficiency so that the entire bottom surface of the printed circuit board 1 is brought into contact, and the heat that can be generated by the power supply is attached. The member U can dissipate heat. Therefore, the power transformer T can also efficiently dissipate the heat that can be generated by attaching the DC stabilized power supply according to the present invention to the attachment member U. Even if the transformer T is downsized / thinned, it is possible to easily ensure the heat dissipation without providing a dedicated heat dissipating member in the power transformer T at all.

  In addition, by mounting a small and simple heat dissipation member (not shown) in combination with the power transformer T as compared with the conventional case, the power transformer T can be more efficiently obtained by the heat radiation by the heat radiation member and the heat radiation by the mounting member U. The heat dissipation may be performed. Further, without attaching the attachment member U, the entire bottom surface of the printed circuit board 1 is brought into contact with one surface of a housing 3 (case) having a good heat conduction efficiency such as a home appliance such as a television or a personal computer or an information device. Then, the power supply may be directly attached.

  As described above, the DC stabilized power supply according to the present invention is a combination of the above-described line filter LF and power supply transformer T, other resistors R, capacitors C, inductors L or switching elements S, and other surface mount components. Provided as a single-sided mounting type DC stabilized power supply. This makes it possible to reduce the size and thickness of the stabilized DC power supply for the AC power supply. That is, in the DC stabilized power supply, the above components and the circuit wiring pattern CP are not present on the bottom surface side of the printed circuit board 1, and part of the lead wires of the respective components attached to the component mounting surface remain. It does not become the state of. Therefore, even if the housing of the home appliance or information device to which the power source is attached is a conductive material such as metal, the power source is installed without being spaced apart or sandwiching an insulator as in the past. Can be attached, contributing to the downsizing / thinning of home appliances and information devices to which they are attached.

  Further, the present invention relates to a heat generating component of a DC stabilized power supply according to the present invention, particularly a power transformer. Even if the power transformer is not mounted on a printed circuit board in combination with a heat radiating member, the power transformer By efficiently dissipating the heat generated in the above, it has been possible to reduce the size and thickness of a stabilized DC power supply for an AC power supply, which has not been possible in the past. In other words, the fact that there is no need to attach a dedicated heat radiating member to the power transformer means that the power transformer can be mounted on the surface, thereby reducing the size and thickness of the stabilized DC power supply for AC power supplies. It contributes greatly.

As mentioned above, although an example of embodiment was demonstrated based on drawing, this invention is not limited to this, It cannot be overemphasized that various embodiment is possible. For example, a pattern that is not related to circuit formation (such as a pattern such as a ground or a frame ground pattern that is not electrically related) may be formed on the bottom surface of the printed circuit board 1. Further, the printed circuit board 1 may be a multilayer board. In this case, instead of providing the component and circuit formation pattern on the bottom surface, the circuit formation pattern is formed on each layer other than the bottom surface including the surface on which the component is mounted. May be provided.
Needless to say, the DC stabilized power source for the AC power source is not limited to the switching regulator type power source as described above, and various types may be used. Further, the stabilized DC power supply for the AC power supply is not limited to the one including all the circuit configurations as described above.

DESCRIPTION OF SYMBOLS 1 ... Printed circuit board 2 ... Insulation sheet 3 ... Case B ... Bobbin Ba ... Core part Bb ... Jaw part Bc ... Opening C ... Capacitor CK ... Resonance capacitor CP ... Circuit wiring pattern D ... Pin terminal E ... Lead terminal F ... Drum core Fa ... Core portion H ... Through hole L ... Inductor LF ... Line filter LP1-LP4 ... Winding M ... Interlayer tape N ... Step R ... Resistance S ... Switching element (MOS transistor)
S1 ... Input noise filter circuit S2 ... Rectification smoothing circuit S3 ... DC-DC converter circuit S4 ... Control circuit T ... Power transformer U ... Mounting member Z ... Insulating tape

Claims (2)

A stabilized DC power supply for an AC power supply that performs AC / DC conversion,
A plurality of circuit components including a transformer;
A printed circuit board formed by forming a printed wiring pattern for connecting each circuit component on only one side of the circuit board,
A single-sided direct current stabilized power supply, wherein all of the plurality of circuit components are surface-mounted only on one side of the substrate on which the printed wiring pattern is formed. An attachment member for attaching the printed circuit board;
The transformer does not come with a dedicated heat dissipation member,
By disposing the surface of the printed board opposite to one side of the board on which the printed wiring pattern is formed in contact with the mounting member, heat generated from the transformer is radiated through the mounting member. The single-sided mounting type DC stabilized power supply according to claim 1.

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