EP1657791A1 - Plug-in power pack - Google Patents

Abstract

The pack has a housing with two circuit carriers (118, 120) that carry primary and secondary side circuits. The circuits are connected with respective primary and secondary sides of a transformer, which is arranged in the housing. The carriers run transverse to each other, and the carrier (120) is accommodated in an electrically insulated tank, such that the carrier is electrically insulated with regard to the carrier (118). An independent claim is also included for a method of manufacturing a plug power supply pack.

Description

The present invention relates to a power supply with a housing and two recorded therein circuit carriers. In particular, the present invention relates to a plug-in power supply that can be integrated in a plug, for example a European plug.

Plug-in power supplies in the small power range are nowadays increasingly implemented as switching power supplies. Due to the small size and low weight, they have prevailed in many applications and displace the formerly common linear devices. Thanks to constant improvements, years ago, it was possible to install a plug-in power supply with an output power of approximately three watts in a small housing.

Examples of such miniaturized plug-in power supply units are given in WO 03/094305 A1. It is known on the one hand, a continuous circuit board, which receives the entirety of the electronic components, so both the secondary-side as well as the primary-side circuit elements to orient parallel to a longitudinal side of the device.

On the other hand, from WO 03/094305 A1 a particularly small realization of such a plug-in power supply is known, in which the entire functionality is accommodated in a European plug. Such miniaturization is a desirable development, especially in connection with travel adapters for charging mobile phones. In this document, it is proposed to produce a housing of two half-shells, and to make the necessary according to the relevant standards distances for air and creepage paths by introducing overlapping ribs. The two half shells are then welded together by means of ultrasound.

According to this document, the outer contour of the plug body does not exceed the dimensions of a European connector according to standard. To accommodate the circuits a single circuit carrier for receiving all electronic components is proposed, which is parallel to the narrow side of the housing. All components of the primary and secondary side are mounted on the same level and are separated only by the aforementioned partitions.

Basically, power supplies worldwide must meet certain standards regarding safety-related aspects. For example, the international standard IEC 60950 describes the requirements for the insulation and the minimum distances between components with different voltage levels. IEC 61000 concerns the minimum requirements for electromagnetic compatibility (EMC). With regard to the types of connectors, the standard EN 50075 concerns the so-called European connectors.

In addition to the extensive miniaturization to increase the ease of use and the price of a plug-in power supply is an essential purchase criterion. Therefore, the focus of today's development is in addition to the miniaturization in a cost reduction. An essential element of a switched-mode power supply is the primary line filter whose components greatly influence the manufacturing costs of the entire plug-in power supply.

FIG. 6 shows a circuit diagram of a known primary network filter of this type. Essentially, this filter fulfills two functions: On the one hand, in the capacitors C1 and C2, the 100 Hz half-waves are sifted out of the rectified mains voltage. On the other hand, it also acts as a low-pass filter for the high-frequency interference spectra occurring when switching the converter transformer in the direction of the mains socket and thus acts as a line filter.

The most cost-effective solution here is a so-called PI filter, which is formed from two capacitors C1 and C2 and an intermediate mushroom core choke L, proven. The use of two approximately equal-sized electrolytic capacitors is required to build the circuit as cost-effectively as possible. For example, for devices with an output power of 1 to 10 watts values from twice 1 μF to twice 10 μF proven. Although the same effect can also be achieved by doubling the capacitance of C2 to, for example, 2.2 μF to 22 μF and choosing a ceramic capacitor, for example with a capacitance of 100 nF, for C1, such a circuit has considerable additional costs As a result, and therefore more expensive manufacturing unnecessarily.

Considering now integrated in a European plug-in power supply according to the publication WO 03/094305 A1, it is found that for the realization of a primary network filter with two electrolytic capacitors in this circuit is not enough space available, since the space for a primary-side and a secondary side electrolytic capacitor is needed. Therefore, the design proposed here is not suitable for further cost reduction.

Furthermore, the solution shown in this document to provide the necessary insulation by dividers available, the decisive disadvantage that any change in the arrangement of the components always has a tool change with displaced dividers result. For the realization of customized variants, however, a flexible arrangement of the components is desirable with unchanged housing structures. Furthermore, the separation of the housing into two half-shells welded together has proved to be less than optimal, since along these outer housing separation lines sufficient strength against electrostatic discharges (ESD, electrostatic discharge) is ensured. A circumferential collar to improve the ESD resistance can be realized in such a separation area arranged only by dispensing with valuable space and is therefore out of the question here.

In addition, the low wall thicknesses in the upper area of the plug pins prevent a reliable and robust connection. Problems arise with the solution shown in this document to pass the torque test of the connector pin (ie 0.2 Nm, one minute in the right / left). The chemical resistance is unsatisfactory and leads z. B. when exposed to oils or fats to an unwanted loosening of the welded joint, to open the housing and to the risk of contact with live parts.

Another disadvantage of the arrangement shown in WO 03/094305 A1 consists in the fact that the housing in the upper part does not widen over the contour of the European connector and may rise above the depth of the socket. Although this meets the desire for minimum size, but requires the user that this must fit deep into the socket to pull out the device again. Furthermore, the user finds no resistance to gripping the device, so especially children have difficulty in handling and possibly bring into danger or pull out the power adapter on the output cable. This is reinforced by the central arrangement of the Zugentlastungstülle according to the document WO 03/094305 A1.

Therefore, the object underlying the present invention is to overcome the above-mentioned deficiencies of the known solution and to accommodate a low-cost, compact plug-in power supply substantially in the contour of a power plug.

This object is achieved by a plug-in power supply with the features of claim 1. Furthermore, the object is achieved by an associated manufacturing method with the steps of claim 16.

Advantageous developments are the subject of several dependent claims.

The present invention is based on the idea to build in a plug-in power supply, the primary-side circuit and the secondary-side circuit on separate circuit carriers and to arrange these two circuit carriers in a manner that their planes are transverse to each other. In this case, circuit carriers are understood to be any type of substrate on which electronic circuits can be constructed and electrically connected to one another, such as, for example, printed circuit boards, ceramic circuit carriers, flexible circuit carriers and the like. Advantageously, such a division of secondary-side and primary-side components on mutually transverse planes on the one hand optimal utilization of the available space, on the other hand, a particularly simple compliance with the applicable provisions with respect to the electrical insulation between the primary-side and the secondary-side components guarantee.

With this solution, a very extensive miniaturization of a plug-in power supply as well as a flexibility in the design of the circuits contained can be achieved at the same time cost manufacturability, meeting all relevant safety standards and high robustness in an advantageous manner.

According to an advantageous development, at least one of the circuit carriers is accommodated in an electrically insulating tray, so that it is electrically insulated from the other circuit carrier. The provision of such a tub, which may be a separate separate from the housing part, preferably made of plastic, is that the required potential separation and compliance with the required air and creepage distances can be carried out in a particularly simple and secure manner.

A particularly compact design, in particular in connection with the realization of the plug-in power supply as a European plug, can be achieved if the plug-in power supply has two plug pins for connecting the plug-in power supply to the supply voltage and the primary-side circuit carrier is accommodated in the housing so that it is substantially along the Plug-in direction of the connector pin extends, and the secondary side circuit substrate is arranged so that it extends transversely to the direction of insertion. In this solution, it makes sense to accommodate the secondary-side circuit carrier in an insulating well, and thus to isolate from the primary-side circuit. The connection of the two circuit boards with each other can then via the output terminals of the converter, so for example, the ends of the secondary winding of a transformer transformer or additional extensions, for. B. connecting wires done.

According to an advantageous development, the housing has a quiver-shaped bottom part which accommodates the circuit carriers, and a cover part which is separate therefrom for closing the housing. This separation of the housing in a plane transverse to the direction of insertion into the power outlet, the ESD resistance can be significantly improved.

If, furthermore, a circumferential collar, which is accommodated in the bottom part, continues to be formed on the cover part, a corresponding path extension is formed which significantly reduces the penetration of electrostatic discharges to the components of the switched-mode power supply. Furthermore, in this design, the possibly critical interface is located in a place that does not necessarily have to be touched.

The welding of the quiver-shaped bottom part with the cover part is preferably carried out by means of ultrasound and is a particularly stable and cost-effective way of connecting between two prefabricated plastic parts.

According to an advantageous development, the plug pins are injected in the housing. This makes it possible to comply with the tests required for Euro plug pins (for example, the pull-out and turn-out test in accordance with EN 50075 or DIN VDI 0620).

If a first and a second filter capacitor of the primary-side circuit are arranged on the primary-side circuit carrier such that the converter is located between the two capacitors, the available installation space can be used optimally and costs can be saved by using comparatively large capacitor components ,

By interconnecting these two filter capacitors with an inductance to a PI filter, a primary line filter can be formed, which efficiently prevents backscattering of interference frequencies in the network.

If it is envisaged that the electrical connection between the primary-side circuit carrier and the secondary-side circuit carrier takes place via the secondary-side connections of the converter, then both the mechanical and the electrical connection of the two circuit carriers can be realized with one another in a simple manner.

The advantageous features of the present invention are particularly useful when the converter is a transformer having a primary-side and a secondary-side winding. Then, in order to comply with the requirements of the international standard IEC 950, the secondary winding can be manufactured from triple insulated wire.

Alternatively, of course, a piezoelectric transducer can be used.

If at least one output terminal for connecting the plug-in power supply unit to a consumer, which is arranged outside the center axis of the plug-in power supply unit and can be formed, for example, by a secondary-side cable, can be found at the plug-in power supply unit, the endeavor of a user to disconnect the device from the line To be pulled out of the socket. As an alternative to the output line can of course also be provided a plug connection.

The advantageous properties of the solution according to the invention come into play particularly when the plug-in power supply is essentially accommodated in the contour of a European plug. Of course, however, the principles of the invention can also be applied in the case of all other plug forms, for example the US plug standard. It may also be necessary in accordance with the geometric dimensions to accommodate the respective larger circuit board transversely to the direction of insertion into the mains socket. Furthermore, of course, any other numbers of pins can be provided and the invention is not limited to the two pins shown as a special case in the case of the European connector.

Figur 1

eine Seitenansicht des erfindungsgemäßen Steckernetzteils;

Figur 2

einen Schnitt durch das Steckernetzteil aus Figur 1;

Figur 3

einen weiteren Schnitt durch das Steckernetzteil aus Figur 1;

Figur 4

eine um 180° gedrehte Ansicht des Steckernetzteils aus Figur 1;

Figur 5

einen Schnitt durch das Steckernetzteil der Figur 4 entlang der Schnittlinie A-A;

Figur 6

ein Schaltbild eines primären Netzfilters und Siebglieds.

Based on the embodiments shown in the accompanying drawings, the invention will be explained in more detail below. Similar or corresponding details of the plug-in power supply according to the invention are provided in the figures with the same reference numerals. Show it:

FIG. 1

a side view of the plug-in power supply according to the invention;

FIG. 2

a section through the plug-in power supply of Figure 1;

FIG. 3

a further section through the plug-in power supply of Figure 1;

FIG. 4

a rotated by 180 ° view of the power supply of Figure 1;

FIG. 5

a section through the power supply of Figure 4 along the section line AA;

FIG. 6

a circuit diagram of a primary network filter and screen member.

Figure 1 shows a side view of the plug-in power supply 100 according to the invention according to an advantageous embodiment. In the embodiment shown, the plug-in power supply is integrated in the contour of a European plug and has plug pins 102, which correspond to the standards for European plug. However, it is clear that the principles shown below can also be applied to plug systems according to other standards, for example the US standard or the Japanese standard.

The plug pins 102 are used for electrical connection to a corresponding mains socket (not shown in the figures). Alternatively, but also connectors z. B. be provided for contacting a cigarette lighter.

According to the invention, a housing 104 is formed by a quiver-shaped bottom part 106, in which the electronic components are accommodated, and a cover part 108 arranged on the secondary side. The connection between the quiver-shaped bottom part 106 and the cover part 108 is preferably carried out via an ultrasonic welding process. A raised or deepened recessed grip 110 allows the removal of the AC adapter 100 from the power outlet, without claiming the Zugentlastungstülle 112 or the cover member 108. From the strain relief grommet 112, a supply cable 114 leads to a consumer 116 to be supplied. In this case, the consumer 116 may be a mobile telephone, a playback device, such as a CD player, a so-called PDA (the abbreviation PDA stands for Personal Digital Assistant ). or the like.

A sectional view of the plug-in power supply unit from FIG. 1 is shown in FIG. It can be seen that the primary-side and the secondary-side components are accommodated on respectively primary side and secondary side circuit carriers 118, 120 which are separate from one another. According to the invention, the plane of the secondary-side printed circuit board 120 extends transversely to the plane of the primary-side printed circuit board 118. In order to achieve the required electrical insulation, the secondary-side circuit substrate 120 is at least partially accommodated in an insulating trough 122.

The housing 104 is formed by a quiver-shaped bottom part 106 and a cover part 108 arranged on the secondary side. In the quiver-shaped bottom portion 106, which is preferably made of plastic by injection molding, the plug pins 102, as is basically known, injected. The plug pins can be plugged in one direction 124 into a mains socket. Furthermore, it can be seen that the primary-side circuit carrier 118 is arranged substantially parallel to the plug-in direction 124 in the quiver-shaped bottom part 106. The plug pins are connected to the primary side circuit substrate 118 via connectors 126. In the solution according to the invention, the primary side is not subject to any restrictions on the placement of the components. The converter 128 and all other circuit parts can be arranged flexibly to a large extent and thus customized variants can be realized without changing tools. A modified division of the volumes for primary and secondary area is also possible in a simple manner.

In the embodiment shown in FIG. 2, the line filter according to FIG. 6 is realized with two primary electrolytic capacitors C1 and C2 in order to be able to construct the circuit with minimum cost. In this case, in order to make optimal use of the available installation space, the two capacitors C1 and C2 are arranged so that the converter transformer 128 lies between them. The separation of the housing in the upper area advantageously relieves the stress of the ultrasonic welding connection from mechanical stress. As can also be seen from FIG. 2, the cover part 108 has a circumferential collar 130 which offers a travel extension for possibly occurring ESD voltage peaks and thus prevents the components inside the switched-mode power supply 100 from being damaged.

The strain relief grommet 112 has been positioned eccentrically and tangentially in the illustrated embodiment to prevent a user from unplugging the power adapter 100 from the power outlet 114 (not shown). The quiver-shaped bottom part 106 widens circumferentially slightly conically in the direction of the cover part 108 in order to ensure better handling. By this slightly conical shape in conjunction with the convex outwardly shaped recessed grip 110 shown in Figure 1, the device can be safely removed from sockets with large clamping forces without having to reach deep into the socket. Alternatively, the recessed grip 110 can also be recessed concavely inwards.

A sectional view in which only the housing 104 and the spout 112 are cut is shown in FIG. It can be seen from this drawing that the insulating well 122 encloses the secondary side circuit substrate substantially from five sides, namely the bottom surface and the side surfaces, and is opened only at the strain relief spout 112 and toward the lid 108. The connection to the transducer 128 via two soldered leads 132 which are connected to the secondary side outputs of the converter. The supply lines 132 are led into the insulating trough 122 via slots 134. Alternatively, of course, suitable connectors can be provided. Furthermore, an arrangement is possible in which the secondary circuit board is mounted in the tub is that the components point down into the tub and the circuit board acts as a kind of cover for the tub.

A 180 ° rotated overview of the power supply 100 of Figure 1 is shown in Figure 4. Along the section line A-A, the section shown in FIG. 5 runs through the plug-in power supply 100.

As can be seen from FIG. 5, the primary-side circuit carrier 118 is held in two grooves 136, which are attached to the quiver-shaped bottom part 106, by the pressure of the capacitors C1, C2 against the opposite housing wall.

The assembly of the plug-in power supply 100 according to the invention will be explained below with reference to Figures 1 to 5 in detail.

First, the quiver-shaped bottom portion 106 and the lid portion 108 and the insulating pan 122 are manufactured as separate parts. In this case, the plug pins 102 are suitably miteingespritzt in the quiver-shaped bottom portion 106. The primary-side circuit carrier 118 is equipped with the primary-side components, including the transducer 128 and the two primary-side capacitors C1 and C2 and a suitable connector 126, and the necessary electrical connections are made for example by a soldering process.

Furthermore, the secondary side circuit substrate 120 is independently equipped with the components required for the secondary side and also the required electrical connection z. B. produced by soldering.

During assembly, in the embodiment shown, the populated primary-side circuit carrier 118 is first introduced along the direction 124 into the quiver-shaped bottom part 106. In this case, the circuit carrier 118 is guided and held in the grooves 136 on the one hand and by the voltage applied to the capacitors C1 and C2 housing walls on the other hand.

The primary-side circuit carrier 118 is inserted until it comes into contact with the stop edges 138 and at the same time the plug pins 102 with the terminals or primary contact springs 126 are fixed or flexible by spring force. At this time, the leads 132 may be connected to the secondary side outputs of the converter 128. Alternatively, however, they may also be provided already during assembly of the components on the primary-side circuit carrier 118.

Irrespective of this, the secondary-side circuit carrier 120 is inserted into the insulating trough 122 and then the trough is inserted into the cup-shaped bottom part 106 until the trough lies flush on the primary-side printed circuit board 118.

The leads 132 may now be inserted through the slots 134 into the insulating well 122.

In a next step, the secondary-side connecting line 114 (not shown in the sectional views) can be passed through the strain relief spout 102 and connected to the secondary-side circuit. Alternatively, the secondary-side connection line 114 can also be connected to it during assembly of the components of the secondary-side circuit carrier. The strain relief spout 112 is then mounted to the quiver-shaped bottom portion 106. The entire housing is closed by means of the lid 108, which is pressed in the direction 124.

In a final ultrasonic welding step, the lid part 108 and the cup-shaped bottom part 106 are firmly connected to each other. Alternatively, of course, other connection methods (such as gluing, screws, rivets, etc.) can be applied.

The implementation according to the invention shown above of a plug-in power supply integrated in a European plug allows a flexible arrangement of the circuit elements, in particular the primary-side components, a more efficient and safe separation of the primary side and the secondary side, a more robust connection technology of the housing parts and improved ESD resistance. The ergonomically designed housing increases user comfort and safety. However, it will be appreciated that the inventive principles are also applicable to plug-in power supplies that satisfy other plug standards, such as Japanese or US American. The number and design of the plug pins can be adapted to the respective standard to be met.

Claims (21)

Plug-in power supply unit with a housing (104) and two separate circuit carriers (118, 120) accommodated therein, which carry a primary-side circuit and a secondary-side circuit,
wherein the primary side circuit is connected to a primary side of a transducer (128) disposed in the housing (104) and the secondary side circuit is connected to a secondary side of the transducer (128), and
wherein the two circuit carriers (118, 120) extend transversely to one another. Plug-in power supply according to claim 1, wherein at least one of the circuit carriers (120) is accommodated in an electrically insulating trough (122) so that it is electrically insulated from the other circuit carrier (118). Plug-in power supply according to claim 1 or 2, wherein the plug-in power supply (100) has two plug pins (102) for connecting the plug-in power supply (100) to a supply voltage and the primary-side circuit carrier (118) is received in the housing (104) so that it substantially along the plug-in direction (124) of the plug pins (102), and the secondary-side circuit carrier (120) is arranged so that it extends transversely to the plug-in direction (124). A power supply according to claim 3, wherein the plug pins (102) are injected in the housing (104). Plug-in power supply according to at least one of the preceding claims, wherein the housing (104) has a quiver-shaped bottom part (106) which accommodates the circuit carriers (118, 120), and a lid part (108) which is separate therefrom for closing the housing (104). Plug-in power supply according to claim 4 or 5, wherein the cover part (108) has a circumferential collar (130) which is received in the bottom part (106). Plug-in power supply according to one of claims 4 to 6, wherein the quiver-shaped bottom part (106) and the cover part (108), preferably by means of ultrasonic welding, welded together. Plug-in power supply according to at least one of the preceding claims, wherein the primary-side circuit (18) has a first (C1) and a second (C2) filter capacitor, which are arranged on the primary-side circuit carrier (118) so that the transducer (128) between the two Capacitors (C1, C2) is located. Plug power supply according to claim 8, wherein the two filter capacitors (C1, C2) are connected to an inductance (L) to a PI filter, so that a primary line filter is formed. Plug-type power supply unit according to at least one of the preceding claims, wherein the electrical connection between the primary-side circuit carrier (118) and the secondary-side circuit carrier (120) via secondary-side terminals of the converter (128). Plug-in power supply according to at least one of the preceding claims, wherein the converter (128) is a transformer having a primary-side and a secondary-side winding. A mains adapter according to claim 11, wherein the secondary-side winding is made of triple-insulated wire. Plug-in power supply according to at least one of the preceding claims, wherein the transducer (128) is a piezoelectric transducer. Plug-in power supply according to at least one of the preceding claims, wherein the plug-in power supply (100) further comprises at least one output terminal (114) for connecting the plug-in power supply with a consumer (116) and the output terminal is arranged outside a central axis of the plug-in power supply. Plug-in power supply according to at least one of the preceding claims, wherein the plug-in power supply (100) is designed so that it in terms of its dimensions, distances and properties of a European standard for power plugs equivalent. A method for producing a plug-in power supply unit with a housing and two separate circuit carriers accommodated therein, which carry a primary-side circuit and a secondary-side circuit, the method comprising the following steps: Introducing the primary-side circuit carrier into the housing, Introducing the secondary-side circuit carrier into the housing so that the two circuit carriers extend transversely to one another. The method of claim 16, wherein prior to introducing the primary side and / or secondary side circuit substrate into the housing, the circuit carrier is introduced into an electrically insulating pan. A method according to any one of claims 16 or 17, wherein the housing has a quiver-shaped bottom part in which the circuit carriers are accommodated, and the method further comprises the step of: Closing the housing with a cover part. The method of claim 18 wherein the step of sealing is by ultrasonic welding. Method according to one of claims 16 to 19, wherein the plug-in power supply has two connector pins for connecting the plug-in power supply to a supply voltage, and is inserted for introducing the primary-side circuit substrate into the housing of the primary-side circuit carrier substantially in a plugging direction of the plug pins until an electrical connection between the connector pins and the primary-side circuit substrate is made. The method of claim 20, wherein the secondary-side circuit carrier is inserted in the plug-in direction of the plug pins in the housing so that it is arranged transversely to the primary-side circuit carrier.

Images