(12) Patent Application Publication (10) Pub. No.: US 2009/ A1

Transcription

1 (19) United State US A1 (12) Patent Application Publication (10) Pub. No.: US 2009/ A1 Lindholm et al. (43) Pub. Date: Dec. 31, 2009 (54) FOIL WINDING PULSE TRANSFORMER (76) Inventor: Mikael Rolf Lindholm, Enkoping (SE); Bengt Anderberg, Uppala (SE) Correpondence Addre: NIXON & VANDERHYE, PC 901 NORTH GLEBE ROAD, 11TH FLOOR ARLINGTON, VA (US) (21) Appl. No.: 11/991,805 (22) PCT Filed: Sep. 18, 2006 (86). PCT No.: PCT/SE2006/OO1062 S371 (c)(1), (2), (4) Date: Sep. 8, 2009 Related U.S. Application Data (60) Proviional application No. 60/718,314, filed on Sep. 20, Publication Claification (51) Int. Cl. HOIF 27/28 ( ) HOIF 4L/06 ( ) (52) U.S. Cl /222:29/605 (57) ABSTRACT A pule tranformer arrangement (100) i built from an uncut pule tranformer core (110) and at leat one foil winding (120-A, 120-B) (each) compriing multiple inulated con ducting trip arranged around the core and ending in foil winding terminal to form multiple independent primary winding. Thi new deign principle ha everal advantage. Making the winding() of foil eliminate the need to cut the core, becaue of the eae of inertion of the foil winding() onto the core. The work to et up a plurality of primary winding i ignificantly reduced. In addition to the elimina tion of the cot for cutting the core, thi alo bring the further advantage of reduced DC reet current, reduced rik for electrical hort and avoidance of exceive loe due to potential high frequency AC reitance problem.

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3 Patent Application Publication Dec. 31, 2009 Sheet 2 of 6 US 2009/ A1 120

4 Patent Application Publication Dec. 31, 2009 Sheet 3 of 6 US 2009/ A1 START PROVIDEAN UNCUTPULSE TRANSFORMER CORE S1 MAKEAFOIL WINDING WITH MULTIPLE INSULATED CONDUCTING STRIPS ENDING AS2 IN TERMINALS TO FORM MULTIPLE INDEPENDENT PRIMARY WINDINGS WRAPPING THE MULTISTRIPFOIL WINDING FORMING MULTIPLE PRIMARY V S3 WINDINGS AROUND THE CORE Fig. 3

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6 Patent Application Publication Dec. 31, 2009 Sheet S of 6 US 2009/ A1

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8 US 2009/ A1 Dec. 31, 2009 FOIL WINDING PULSE TRANSFORMER TECHNICAL FIELD The preent invention relate to pule tranformer, a novel winding arrangement a well a a method of effi ciently making a pule tranformer with Such a winding arrangement. BACKGROUND 0002 Electrical power ytem can be found in virtually all indutrial area, and they normally involve ome form of circuitry for controllably tranferring electrical power or energy to the intended load. A particular example of a com monly ued power ytem i a power modulator, which can be regarded a a device that control the flow of electrical power. When a power modulator i deigned for generating electrical pule it i alo referred to a a pule modulator or pule generator. In it mot common form, a power modulator deliver high power electrical pule to a pecialized load. By way of example, high power electrical pule are utilized for powering microwave amplifier tube in driving electron accelerator Sytem and/or microwave generating ytem for application uch a medical radiation application and radar application A key component in power modulator i the pule tranformer, which baically comprie a tranformer core, one or more primary winding and one or more econdary winding. The pule tranformer i ued for tranferring pule energy from the primary ide to the econdary ide, normally with a change in Voltage and current. The tranformer core i made of Some magnetic material, and the winding are gen erally made of copper wire. In operation, the tranformer i often placed inapule tranformer tank, where a uitable fluid Such a oil can cool the component efficiently and provide electrical inulation Tranformer core for hort pule in the range of a few microecond are uually made of wound tape of ilicon iron. Thi tape i typically only 0.05 mm thick. Thi i nec eary for the reduction of loe in the core. To allow for practical application of the coil/winding, the core i gener ally cut into two halve. When the halve are reconnected, the gap left mut be minimized and therefore the urface have to be ground flat and poibly etched to eliminate hort between the tape layer. There mut alo be a thin inulation between the halve for thi reaon. SUMMARY The preent invention overcome thee and other drawback of the prior art arrangement It i a general object of the invention to provide an improved pule tranformer deign It i alo an object of the invention to provide a novel method of manufacturing a pule tranformer arrangement The invention propoe a new way to deign a pule tranformer arrangement. The conventional way i to cut a tranformer core into halve, inert winding on the cut core and reconnecting the core halve while minimizing the gap between the halve. The invention on the other hand provide a pule tranformer arrangement which i built from an uncut pule tranformer core and a foil winding compriing mul tiple inulated conducting trip arranged around the core and ending in foil winding terminal to form a et of multiple independent primary winding Thi new deign principle ha everal advantage. Making the winding() of foil eliminate the need to cut the core, becaue of the eae of inertion of the foil winding() onto the core. The work to et up a plurality of primary winding i ignificantly reduced. In addition to the elimina tion of the cot for cutting the core, thi alo bring the further advantage of reduced DC reet current, reduced rik for electrical hort and avoidance of exceive loe due to potential high frequency AC reitance problem Preferably, the multiple primary winding and their termination may be formed on a ingle conducting foil depoited on an inulating foil. Advantageouly, the multi trip foil winding only need to be wrapped a ingle turn around the uncut tranformer core to form a plurality of independent (i.e. inulated from each other) primary wind ing with end terminal ready for connection. The connec tion can then be made for example imply by attaching tandard multi-pin connector or any other conventional con nection arrangement to the end of the conducting foil trip It i alo poible to efficiently form a econdary winding by diplacing the wire pattern of a multi-trip foil winding by one trip when the foil i wrapped around the core and Soldering the meeting end together to form a econdary winding with a ingle tarting end and a ingle terminating end The invention offer at leat the following advan tage: 0013 Cot-effective deign Reduced manufacturing cot Reduced DC reet current Reduced rik for electrical hort Avoidance of exceive loe due to potential high frequency AC reitance problem Decreaed inductance and reduced rik for park ing. (0019. Other advantage offered by the invention will be appreciated when reading the below decription of embodi ment of the invention. BRIEF DESCRIPTION OF DRAWINGS The novel feature believed characteritic of the invention are et forth in the appended claim. The invention itelf, however, a well a other feature and advantage thereof will be bet undertood by reference to the detailed decription of the pecific embodiment which follow, when read in conjunction with the accompanying drawing, wherein: 0021 FIG. 1 i a chematic drawing illutrating an example of a pule tranformer arrangement according to a preferred embodiment of the invention FIG. 2 illutrate a multi-trip foil winding accord ing to an exemplary embodiment of the invention FIG. 3 i a chematic flow diagram of a method for manufacturing a pule tranformer arrangement according to an exemplary embodiment of the invention FIG. 4 illutrate a winding according to another exemplary embodiment of the invention FIG. 5 how a tranformer arrangement with mul tiple primary foil winding according to an exemplary embodiment of the invention.

9 US 2009/ A1 Dec. 31, FIGS. 6A-B how different view of an example of a tranformer with a novel foil-type primary winding accord ing to a preferred embodiment of the invention. DETAILED DESCRIPTION For a better undertanding of the invention it may be ueful to tart with an analyi of the conventional way to deign a pule tranformer To allow for practical application of the coil/wind ing, the core i traditionally cut into two halve. When the halve are reconnected, the gap left mut be minimized and therefore the urface have to be ground flat and poibly etched to eliminate hort between the tape layer. There mut alo be a thin inulation between the halve for thi reaon However, the inventor have recognized that the introduction of the cut ha ome effect on the performance of the tranformer: 0030 Auming, by way of example, that the remaining gap at the cut i around 0.05 mm it will require ome H-field (ay 80 ampere turn) to drive a 1 T field acro the gap. Thi i advantageou in the way that it will bring the remnant field to near Zero at Zero current, leaving omething like 1 to 1.5 T field rie available for the pule. With no gap the remnant field may be around 1 T, leaving only 0 to 0.5 T for the pule. However, for the efficient ue of the core, a DC current i often applied on an extra winding to offet the field at Zero primary current to a negative field of about 1 to 1.5 T. Thereby a field Swing of up to 3 T i left for the pule. The gap require mot of thi current, and ha therefore a negative effect, requiring larger current upply component. With no cut the DC reet current i typically reduced by a factor of four. In addition to the extra cot involved for cutting the core, there i alo an increaed rik for electrical hort The type of pule tranformer uing everal primary upplie, e.g. a decribed in our U.S. Pat. No. 5,905,646, alo publihed a International PCT Application PCT/SE97/ with International Publication Number WO 98/28845 A1, and our U.S. Pat. No. 6,741,484, alo publihed a Inter national PCT Application PCT/SE02/02398 with Interna tional Publication Number WO 03/061125A1, reult in mul tiple primary winding. With conventional technique, the work to et up all thee winding and to make connection for the winding i time conuming and cotly There i thu a general need for an improved pule tranformer deign A baic idea of the preent invention i to provide a pule tranformer arrangement baed on an uncut pule tran former core and at leat one foil winding having multiple inulated conducting trip arranged around the core and ending in foil winding terminal to form multiple indepen dent primary winding In the example chematically illutrated in FIG. 1, the pule tranformer arrangement 100 baically comprie an uncut core 110, two foil winding 120-A, 120-B and two econdary winding 130-A, 130-B. Each foil winding 120 ha multiple inulated conducting trip arranged around the core to form multiple independent primary winding in a multi wire' pattern. Each foil winding can alo be referred to a a primary foil winding with a multi-wire pattern In a preferred exemplary embodiment of the inven tion, the multiple primary winding and their termination are formed on a ingle conducting foil depoited on an inulating foil. The conducting foil i made of ome Suitable conducting material Such a for example copper. Conveniently, the multi trip foil winding 120 only need to be wrapped a ingle turn around the uncut tranformer core to form a et of indepen dent (i.e. inulated from each other) primary winding with end terminal ready for connection. The multiple conducting trip are generally inulated from each other and extend around the core The wire (conducting trip) are preferably haped on the conducting foil with a common photo-chemical method, for example by uing tandard printed circuit board manufacturing technique In a preferred exemplary embodiment of the inven tion, with the foil technique, the primary winding and their termination are haped on a ingle conducting foil (depo ited on an inulating foil) and the connection are made im ply by attaching for example tandard multi-pin connector (e.g. 15 pin). Thi i another ignificant advantage offered by the preent invention. Although the multi-pin connector arrangement i highly efficient from a manufacturing point of view, it i indeed poible to ue any other commercially available connection arrangement uch a conventional ter minal block oldered to a printed circuit board or oldered into cable Another advantage with the foil winding i that it may eaily cover the full length of the opening of the core with an almot continuou current heet, which give a Smooth ditribution of the electric field. Thi decreae the inductance and rik for parking Making the winding() of foil eliminate the need to cut the core, becaue of the eae of inertion of the foil winding() onto the core. The work to et up a plurality of primary winding i ignificantly reduced. In addition to the elimination of the cot for cutting the core, thi alo bring the further advantage of reduced DC reet current and reduced rik for electrical hort. A ide effect of the new winding principle i that exceive loe due to potential high frequency AC reitance problem are avoided The econdary winding() can be any conventional winding(), and i/are preferably multi-turn econdary wind ing() Foil winding a uch are known from the prior art 1-4), but for different application and with a different deign principle compared to the invention In reference 1 a foil winding in the form of a ingle-trip foil i wrapped in many layer around a conven tional core with uitable interwinding inulation between lay CS Reference 2 relate to a low-voltage foil winding for a high-voltage televiion line tranformer. The foil wind ing i arranged about a core, and the layer of the winding are inulated from each other by an inulating tape which i wound imultaneouly with a conductive foil. The conductive foil form an uninterrupted conductive urface o that the field line in the central portion extend parallel to the wind 1ng. 0044) Reference 3 relate to a power upply conductor from a conductive foil of a foil winding of a power tran former. The power Supply conductor i formed a a conductor tack of flag-haped folded end-piece at one end of the foil winding, and repreent a imple way to provide a narrow tack-formed end terminal from a wider piece of foil Reference 4 relate to a elf lead foil winding for tranformer and inductor. The end portion of a conventional multi-layered foil winding i cut into flag haped portion that are folded or otherwie formed to create tacked elf lead.

10 US 2009/ A1 Dec. 31, 2009 The flag-haped portion are made Sufficiently long o that the reulting tacked elf lead will reach a mounting board for efficient mounting of the tranformer to the board FIG. 2 illutrate a winding according to an exem plary embodiment of the invention. A foil of uitable conduct ing material (e.g. copper) i depoited on a foil of inulating material (e.g. platic material), and trip of the conducting foil are formed in a Suitable wire pattern, e.g. by uing a conventional etching technique. The foil winding 120 illu trated in FIG. 2 i epecially uitable for multiple primary winding. The eparated multiple conducting trip or wire preferably extend all the way along the foil winding. Prefer ably, the primary foil winding i wrapped a ingle turn around the tranformer core, and one end of the winding i then folded at about 45 degree (a hown a a dotted line in FIG. 2) and the other end i configured with a turn at about 90 degree o that the conductor for the incoming current (input terminal) can be arranged very cloe to the conductor for the outgoing current (output terminal) when the two end are finally collected together. Thi decreae leakage field It hould be undertood that although the primary winding formed from the foil are inulated from each other, two or more of the conducting trip on the foil winding may be connected in parallel for pecial type of operation FIG. 3 i a chematic flow diagram of a method for manufacturing a pule tranformer arrangement according to an exemplary embodiment of the invention. The firt tep (S1) i to provide an uncut pule tranformer core. The next tep (S2) i to make a pule tranformer foil winding with multiple inulated conducting trip ending in foil winding terminal to form a et of confined multiple independent primary wind ing. For example, the multi-trip foil winding i preferably made by depoiting a foil of conducting material on a foil of inulating material, and forming multiple conducting trip in a wire pattern on the conducting foil. Subequently, the multi trip foil winding forming multiple primary winding i wrapped around the uncut tranformer core (S3). Optionally, the terminal or end portion of the multiple conducting trip are connected to a multi-pin connector or imilar connection arrangement to provide connection for the multiple primary winding FIG. 4 illutrate a winding according to another exemplary embodiment of the invention. Thi winding truc ture i epecially Suitable a a tarting point for a econdary winding. The wire pattern' on the foil i preferably di placed by one trip when the foil i wrapped (normally in a tapered overall hape) around the core and the meeting end are oldered together to form the winding, a indicated by the dotted line. The offet by one trip provide a natural tarting end (input) and a terminating end (output) for the winding At preent, foil with a thickne of more than 0.05 mm i not eaily available on the commercial market. Thi may limit the average power of the tranformer, unle everal layer of foil are added in the proce of making the winding FIG. 5 how a tranformer with primary foil wind ing without econdary winding. Pleae note that the tran former of FIG. 5 ha two core leg, and that the primary winding on one of the leg i hown without connector to illutrate the cloe proximity between input and output con ductor due to the mart and effective 45 degree fold, wherea the primary winding on the other leg i attached to a multi-pin COnnectOr FIGS. 6A-B how different view of a complete tranformer with a novel foil-type primary winding. In thi particular realization the econdary winding i a conventional wire-type winding. There i of coure nothing that prevent the econdary winding from being a foil-type winding In accordance with preferred embodiment of the invention, at leat one of the primary and econdary winding i/are made out of foil of ome Suitable conducting material Such a for example copper depoited on inulating foil wrapped around the yoke Should the pule tranformer have more than one tranformer core, it i poible to apply the invention with one or more foil winding on each tranformer core The embodiment decribed above are merely given a example, and it hould be undertood that the preent invention i not limited thereto. Further modification, change and improvement which retain the baic underlying principle dicloed herein are within the cope of the inven tion. REFERENCES 0056 (1 Aluminium and Copper Foil Tranformer', Technical Information, ElectroCube, com, Augut U.S. Pat. No. 4,086, U.S. Pat. No. 5,805, (4 U.S. Pat. No. 6,930, (canceled) 20. A pule tranformer arrangement for tranferring pule energy from a primary ide to a econdary ide, aid pule tranformer arrangement compriing: an uncut pule tranformer core; and a foil winding compriing multiple inulated conducting trip arranged around aid uncut pule tranformer core and ending in foil winding terminal to form multiple independent primary winding, wherein aid multi-trip foil winding i wrapped a ingle turn around aid tran former core and aid multiple conducting trip are inu lated from each other and extend around the core. 21. The pule tranformer arrangement of claim 20, wherein aid multiple conducting trip are formed in a wire pattern on a foil of conducting material depoited on a foil of inulating material. 22. The pule tranformer arrangement of claim 20, wherein the terminal of aid multiple conducting trip are connected to a multi-pin connector to provide foil winding connection. 23. The pule tranformer arrangement of claim 22, wherein aid multi-trip foil winding i made from a flexible printed circuit board adapted for tandard multi-pin connec tors. 24. The pule tranformer arrangement of claim 20, wherein aid foil winding ubtantially cover the length of the opening of aid tranformer core to provide a Smooth ditribution of the electrical field. 25. The pule tranformer arrangement of claim 20, wherein at leat a Subet of aid multiple conducting trip, in operation, are connected in parallel. 26. The pule tranformer arrangement of claim 20, wherein aid foil winding i wrapped around the tranformer core and one end of aid foil winding i folded at about 45 degree and the other end i configured with a turn of about 90 degree o that input terminal can be arranged in cloe prox imity to output terminal when the two end of the foil wind ing are collected together.

11 US 2009/ A1 Dec. 31, The pule tranformer arrangement of claim 20, further compriing a econdary winding wrapped around the core. 28. A method of manufacturing a pule tranformer arrangement for tranferring pule energy from a primary ide to a econdary ide, aid method compriing the tep of providing an uncut pule tranformer core; making a pule tranformer foil winding with multiple inulated conducting top ending in foil winding termi nal to form multiple independent primary winding; wrapping aid multi-trip foil winding forming multiple primary winding a ingle turn around aid uncut tran former core, aid multiple conducting trip being inu lated from each other and extending around the core. 29. The method of claim 28, wherein aid tep of making a pule tranformer foil winding with multiple inulated con ducting trip comprie the tep of: depoiting a foil of conducting material on a foil of inu lating material; and forming multiple conducting trip in a wire pattern on the conducting foil. 30. The method of claim 28, wherein the terminal of aid multiple conducting trip are connected to a multi-pin con nector to provide connection for aid multiple primary wind 1ngS. 31. The method of claim 30, wherein aid multi-trip foil winding i made from a flexible printed circuit board adapted for tandard multi-pin connector. 32. The method of claim 28, wherein aid multi-trip foil winding i arranged Subtantially over the full length of the opening of aid tranformer core to provide a Smooth ditri bution of the electrical field. 33. The method of claim 28, further compriing the tep of folding, after wrapping aid multi-trip foil winding around aid uncut tranformer core, one end of aid foil winding at about 45 degree and the other end i configured with a turn of about 90 degree o that input terminal can be arranged in cloe proximity to output terminal when the two end of the foil winding are collected together. 34. The method of claim 28, wherein a econdary winding i further wrapped around aid tranformer core. c c c c c