GB2250383A - Coil comprising multi layer printed circuit boards - Google Patents
Coil comprising multi layer printed circuit boards Download PDFInfo
- Publication number
- GB2250383A GB2250383A GB9121061A GB9121061A GB2250383A GB 2250383 A GB2250383 A GB 2250383A GB 9121061 A GB9121061 A GB 9121061A GB 9121061 A GB9121061 A GB 9121061A GB 2250383 A GB2250383 A GB 2250383A
- Authority
- GB
- United Kingdom
- Prior art keywords
- coil
- printed wiring
- high frequency
- wiring boards
- sides
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000010030 laminating Methods 0.000 claims abstract description 10
- 239000000758 substrate Substances 0.000 claims description 19
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 14
- 238000004804 winding Methods 0.000 abstract description 24
- 238000010276 construction Methods 0.000 description 12
- 238000000034 method Methods 0.000 description 8
- 238000004519 manufacturing process Methods 0.000 description 7
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 239000011810 insulating material Substances 0.000 description 3
- 230000006641 stabilisation Effects 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F19/00—Fixed transformers or mutual inductances of the signal type
- H01F19/04—Transformers or mutual inductances suitable for handling frequencies considerably beyond the audio range
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F17/00—Fixed inductances of the signal type
- H01F17/0006—Printed inductances
- H01F17/0013—Printed inductances with stacked layers
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Multimedia (AREA)
- Coils Or Transformers For Communication (AREA)
- Coils Of Transformers For General Uses (AREA)
Abstract
An HF iron-cored transformer 15, for e.g. SMPS's, has windings constructed by laminating boards 22 having spirals printed on one or both sides. Reproducibility is enhanced, and leakage inductance may be reduced by alternating primary and secondary boards. Connections between boards are made by through-holes, and by connection lands on each board. A shield board 23 may be used between primary and secondary stacks. <IMAGE>
Description
"HIGH FREQUENCY INDUCTOR"
The present invention is related to a high frequency inductor, such as a transformer or coil for use as high frequency pulse transformers, choke coils, etc.
The conventional high frequency transformer is constructed by winding a winding coil 1 around an iron core 2 as shown in Figures 9(a) and (b) of the accompanying drawings. The winding coil 1 is comprised of a primary winding coil 3 and a secondary winding coil 4. Reference 5 represents wiring terminals.
The windings of the conventional transformers, choke coils and the like are formed by winding an insulated copper wire, insulating paper, etc. (or bobbin) using a winding machine. However, in high frequency transformers, choke coils and the like, deviations in the capacity (stray capacity) between the respective windings and the degree of coupling between the respective windings give a large problem in the matter of characteristics.
Particularly, an increase of the leakage inductance in a pulse transformer for a switching power supply also causes large pr^lems with respect to its characteristics such as reduction of the transformation efficiency due to waveform variation and increase in the generated noise. Accordingly, usually a high degree of winding skill is required, and the present situation is that skilled coil winding workers are winding such coils.
In addition, as is well known, as the miniaturisation and high performance of switching power supplies are increasingly required, the switching frequency is gradually made higher, but the coil winding method is an important point in the high frequency transformer and choke coil used in switching power supplies, and the following properties are desired:
(1) Fixation of the geometric size of each winding (for stabilisation of capacity).
(2) Tight coupling between each winding and stabilisation (for reduction and stabilisation of leakage inductance).
(3) No winding skill is required.
(4) Cost reduction by mass production is possible.
The present invention was developed in view of the defects and desires in the prior art, and seeks to provide a high frequency inductor which has less deviation between each winding, a high-performance and stability, and is suitable for mass production, by using coil printed wiring boards as the coils of the high frequency inductor.
According to the invention, there is provided a high frequency inductor comprising an iron core and a coil, wherein said coil is constructed by laminating a plurality of coil printed wiring boards, each consisting of a substrate provided with a coil-shaped printed circuit thereon.
The high frequency transformer of the present invention comprises an iron cor and a coil wherein the coil is constructed by laminating a plurality of coil printed wiring boards each comprising a substrate having coil-shaped printed circuits provided thereon.
The high frequency coil of the present invention is characterised by alternately laminating the printed wiring boards for primary and secondary coils, which printed wiring boards each consist of a substrate which is provided with a coil-shaped printed circuit on one or both sides thereof, joiner lands on both sides thereof, and a through-hole land passing through the printed circuit provided on one or both sides thereof, and connecting the respective printed wiring boards for the primary and secondary coils by said joiner lands.Preferably also a plurality of printed wiring boards each consisting of a substrate which is provided with coil-shaped printed circuits on both sides thereof, a through-hole passing through the printed circuits on both sides thereof, and joiner lands on both sides thereof, are connected to each other through the joiner lands thereby to form primary and secondary coils, and the primary and secondary coils are laminated and connected through a shield printed circuit.
By constructing the coil in a high frequency transformer consisting of an iron and a coil by laminating a plurality of coil printed wiring boards, the degree of freedom in selection of the coil characteristics can be increased and the coil characteristics can be stabilised, whereby quality and precision may be increased.
In addition, the geometric size of the coilshaped printed circuits in each coil printed wiring board and the distance between each coil pattern can stably be formed with high precision and without deviation, and the design of circuits corresponding to the number of turns of the coil and adjustment among the respective coil layers can freely be designed by selecting the design of the coil-shaped printed wiring boards or the number of laminated wiring boards and each board thickness, so that the coil of a construction corresponding to the characteristics required for a high frequency coil can be provided independently of the degree of skill of manufacturers.
Further, the respective coil printed wiring boards constituting the high frequency coil can be connected through the respective joiner lands provided on both substrate sides of each wiring board, providing simplicity of lamination.
In order that the invention may be better understood, several embodiments thereof will now be described by way of example only and with reference to the accompanying drawings in which:
Figures 1(a) and (b), Figure 2 and Figures 4 to 8 show a first embodiment of the present invention, in which:
Figures 1 (a) and (b) are a perspective view and longitudinal sectional view of a high frequency transformer, respectively;
Figure 2 is a perspective view of a high frequency coil;
Figure 4 is a perspective view of the coil printed wiring board used for the high frequency coil;
Figure 5 is a sectional view showing a connection state of the coil printed wiring boards;
Figure 6 is a perspective view of the side board of the high frequency coil;
Figure 7 is a perspective view of the shield wiring board of the high frequency coil;;
Figure 8 is an explanatory view showing the manufacturing process of the coil printed wiring boards;
Figure 3 is a perspective view showing a second embodiment of the present invention; and
Figures 9(a) and (b) are explanatory views of a known high frequency transformer.
A first embodiment of the invention will now be described with reference to Figures 1(a) and (b),
Figure 2 and Figures 4 to 8.
In Figure 1, reference 10 is the coil of a high frequency transformer 15 and reference 12 is the iron core thereof.
The coil 10 of the high frequency transformer 15 is constructed, as shown in Figure 1(b) and Figure 2, by connecting primary and secondary coils 13 and 14 formed by laminating a plurality of coil printed wiring boards 22 through a shield printed wiring board 23, and mounting the coil 10 on the iron core 12 thereby to construct the high frequency transformer 15.
In addition, the mounting of the coil 10 on the iron core 12 is performed by fitting the core frames 12c and 12d in the centre of the upper and lower iron cores 12a and 12b in the mounting hold 35 of the coil 10, respectively, and fitting the side frames 12e and 12f of the upper and lower iron cores 12a and 12b over the side portions of the coil 10, with the upper and lower iron cores 12a and 12b being coupled.
Further, a side board 21 is laminated on the coil 10 in addition to the primary and secondary coils 13 and 14, and lead terminals 11 are provided on the side board 23 so as to outwardly project.
The construction of the high frequency coil 10 in the high frequency transformer 15 is now described in detail with reference to Figures 4 to 8.
First, in the coil printed wiring boards 22, as shown in Figure 4, a coil-shaped printed circuit 31 is formed of a copper foil on both sides of a substrate 30 formed of an insulating material, and one end 3ia of the printed circuit 31 is connected to joiner lands 33 provided on both sides of the substrate 30, while the other end 31b is connected to a through-hole land 34 provided in the vicinity of a mounting hole 35 provided in the centre of the substrate 30.
Also, as to such coil printed wiring boards 22, as shown in Figure 8, it is possible to manufacture a plurality of coil printed wiring boards 22 using a double-sided copper-clad laminate 40 such as is used in manufacturing conventional wiring boards - That is, after grooves (e.g. V-grooves) 41 for dividing the respective coil printed wiring boards 22 are cut in the double-sided copper-clad laminate 40 and the work of the mounting hole 35 and through-hole (not shown) of the respective coil printed wiring boards 22 are made, the coil-shaped circuits 31 are formed by an etching process, and after dividing the respective coil printed wiring boards 22 through the dividing grooves 41, a required outer diameter work is done, whereby the coil printed wiring boards 22 shown in Figure 4 can be formed.
In addition, the joiner lands 33 and throughhole land 34 of the respective coil printed wiring boards 22 can be formed simultaneously with the formation of the coil-shaped printed circuits 31, and the printed wiring boards 22 for the primary and secondary coils 13 and 14 can also be formed at the same time on the double-sided copper-clad laminate 40 as shown in Figure 8.
The printed circuits 31 on oth sides are electrically connected through the through-hole lands 34, and their connecting circuit is also formed by a conventional known through-hole plating method or the like.
Moreover, although mention has been made above to. the fact that the coil-shaped printed circuit 31 is provided on both sides of the substrate 30, the provision only on one side can of course be implemented.
However, in the case of a one sided implementation, one terminal 31b of the printed circuit of each coil printed wiring board 22 is electrically connected to the terminal 31b of another printed wiring board 22 through the through-hole land 34.
The method for laminating the respective coil printed wiring boards 22 is constructed by electrically connecting the joiner lands 33 provided on both sides of the respective printed wiring boards 22 laminated one upon another by means of soldering or the like, as shown in Figure 5, and one terminal 31a of the respective circuits 31 are connected to each other by the connection of such joiner lands 33, and the other terminals 31b are electrically connected through the respective through-hole lands 34, for instance, by a method such as filling the respective through-hole with a connecting conductor, whereby the respective printed circuits 31 of the respective coil printed wiring boards 22 can be electrically connected.
Next, referring to Figure 6, in the side board 21 for forming the primary and secondary coils 13 and 14, first a coil-shaped printed circuit 37 is provided on one side of a substrate 36 made of an insulating material, and one end of the printed circuit 37 is connected to a tap land 32a while the other end 37b is connected to a through-hole land 39, which is electrically connected to a joiner land 38 provided on the rear side of the substrate 36.
In addition, a mounting hole 35 is made in the centre of the substrate 36 as in the individual printed wiring board 22, and lead terminals 11 and 16 are provided in the upper end of the substrate 36, and connecting lands 17 and 18 are provided for the lead terminals 11 and 16, respectively.
Moreover, in the printed circuit 37 of the substrate 36, a plurality of tap lands 32b, 32c and 32d for adjusting the number of turns are provided intermediately of the circuit.
As to the side board 21 used for the secondary coil 14, a side board is used which has a pattern opposite to the construction shown in Figure 6, which is used for the primary coil 13.
The side board 21 of such construction can be manufactured by a method similar to the coil printed wiring board 22.
The construction of the shield printed circuit 23 interposed between the primary and secondary coils 13 and 14 will now be described with reference to
Figure 7. Shield layers 51 are deposited on both sides of a substrate 50 formed of an insulating material, and a mounting hole 35 is made in the centre of the substrate 50 as in the individual printed wiring board 22, and in the shield layers 51 on both sides, earth lands 52 and 53 are provided and an earth terminal 54 is provided.
Accordingly, by connecting a plurality of coil printed wiring boards 22 shown in Figure 4 through the joiner lands 33 and connecting the side board 21 through the joiner land 38 to the joiner land 33 of the outermost printed wiring board 22 of the individual printed wiring boards 22, the primary and secondary coils 13 and 14 can be formed.
In addition, by integrating the primary and secondary coils 13 and 14 by interposing the shield printed circuit 23 therebetween, the high frequency coil 10 can be constructed.
Further, the coil-shaped printed circuits 31 of the respective printed wiring boards 22 of the primary and secondary coils 13 and 14 are connected through the joiner lands 33 and through-hole land 34, and connected to the side boards 21 of the primary and secondary sides through the joiner land 38 and lead terminals 11 and 16, and fine adjustment of the number of turns of the primary and secondary coils 13 and 14 can be performed by selection between any of the respective tap lands 32a to 32d of the side boards and the connecting land 17, and the earth connection between the individual coils 13, 14, the shield printed wiring board 23 and the shield layers 51, 52 is provided through the earth lands 52 and 53.
By mounting the high frequency coil 10 of such construction on the iron core 12, the high frequency transformer 15 can be formed.
Incidentally, the high frequency coil 10 shown in Figure 2 has a construction corresponding to the conventional part-winding type, and is characterised in that stray capacity Cs can be made small.
And, structurally, to make this smaller, adjustment can be provided by inserting spacer boards for adjusting the space between the individual printed wiring boards 22, and the printed wiring boards 22 of such construction is optimum for space winding.
Reference is now made to Figure 3 which is a perspective view of a high frequency coil showing a second embodiment of the present invention.
The high frequency coil 24 shown in Figure 3 is constructed by forming printed wiring boards 25 and 26 for the primary and secondary coils by printed wiring boards 22 of the construction shown in the first embodiment, and alternately laminating both printed wiring boards 25 and 26, and the remaining construction is the same as the first embodiment, so that specific description thereof is omitted.
The high frequency coil 24 shown in Figure 3 corresponds to the sandwich winding type of the traditional coil. Leakage inductance can be reduced by tight coupling between the individual coils.
With respect to the high frequency coils 10 and 24 of the first and second embodiments, a high frequency coil of a construction suitable for desired characteristics can simply be formed by combining those coils or by any other proper construction.
As described above, in accordance with the present invention, by fundamentally improving the winding method of a transformer or coil, from the design to the manufacture of a transformer or coil of a higher performance are enabled in a short period of time and at a low cost, and the following inventive effects are provided over the prior art product.
(1) No high degree of skill is required.
(2) By the printed wiring technique, the size precision can be stabilised, and a high performance and high quality can be provided.
(3) Since it is only needed to laminate, combine and adjust printed coils (pieces), the period of design and development can substantially be shortened.
(4) Since coil windings are replaced by printed wirings, more mass production, shorter delivery time and higher cost reduction are enabled.
Claims (5)
1. A high frequency transformer comprising an iron core and a coil, wherein said coil is constructed by laminating a plurality of coil printed wiring boards, each consisting of a substrate provided with a coil-shaped printed circuit thereon.
2. A high frequency coil which is constructed by alternately laminating primary coil printed wiring boards with secondary coil printed wiring boards, each said printed wiring board consisting of a substrate which is provided with a coil-shaped printed circuit on one or both sides thereof, joiner lands on both sides thereof, and a through-hole land passing through the printed circuit provided on one or both sides thereof, and wherein said respective printed wiring boards for the primary and secondary coils are connected by said joiner lands.
3. A high frequency coil comprising a plurality of printed wiring boards, each consisting of a substrate which is provided with coil-shaped printed circuits on both sides thereof, a through-hole passing through the printed circuits on both sides thereof, and joiner lands on both sides thereof, wherein said printed wiring boards are connected to each other by said joiner lands thereby to form primary and secondary coils, and wherein said primary and secondary coils are laminated and connected through a shield printed wiring board.
4. A high frequency transformer substantially as hereinbefore described with reference to Figures 1, 2 and 4 to 8 of the accompanying drawings.
5. A high frequency coil substantially as hereinbefore described with reference to Figure 3 of the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26885890A JPH04144212A (en) | 1990-10-05 | 1990-10-05 | High frequency transformers and coils using printed wiring boards |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9121061D0 GB9121061D0 (en) | 1991-11-13 |
| GB2250383A true GB2250383A (en) | 1992-06-03 |
Family
ID=17464247
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9121061A Withdrawn GB2250383A (en) | 1990-10-05 | 1991-10-03 | Coil comprising multi layer printed circuit boards |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH04144212A (en) |
| GB (1) | GB2250383A (en) |
Cited By (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0656636A1 (en) * | 1993-12-01 | 1995-06-07 | Robert Bosch Gmbh | Transformer with shielding and its use |
| GB2311417A (en) * | 1996-03-22 | 1997-09-24 | Murata Manufacturing Co | Laminated balun transformer |
| US5929733A (en) * | 1993-07-21 | 1999-07-27 | Nagano Japan Radio Co., Ltd. | Multi-layer printed substrate |
| DE19805914A1 (en) * | 1998-02-13 | 1999-08-19 | Thomson Brandt Gmbh | Compact planar transformer for high frequency switched mode power supplies |
| GB2337863A (en) * | 1998-05-09 | 1999-12-01 | Frederick E Bott | Method and means of forming a desired coil configuration |
| US6127911A (en) * | 1998-02-13 | 2000-10-03 | Deutsche Thomson-Brandt Gmbh | Transformer |
| DE19915649A1 (en) * | 1999-04-07 | 2000-10-12 | Rohde & Schwarz | Impedance transformer for a push-pull amplifier of a short or ultra short wave transmitter |
| EP1122873A2 (en) * | 2000-02-07 | 2001-08-08 | Nihon Protector Co., Ltd. | Uninterruptible switching regulator |
| GB2369251A (en) * | 2000-05-22 | 2002-05-22 | Payton Ltd | Method of insulating a planar coil circuit |
| CN101458987B (en) * | 2007-12-11 | 2011-05-04 | 英业达股份有限公司 | Inductive device and manufacturing method thereof |
| WO2011109158A1 (en) * | 2010-03-04 | 2011-09-09 | Bose Corporation | Planar audio amplifier output inductor with current sense |
| US8350537B2 (en) | 2010-03-04 | 2013-01-08 | Bose Corporation | Power supply transient response improving |
| US8384478B2 (en) | 2010-03-04 | 2013-02-26 | Bose Corporation | Versatile audio power amplifier |
| US8400788B2 (en) | 2006-12-20 | 2013-03-19 | Primozone Production Ab | Power supply apparatus for a capacitive load |
| CN103247419A (en) * | 2012-02-09 | 2013-08-14 | 成都市华森电子信息产业有限责任公司 | Inductive element and method for manufacturing the same |
| CN103366931A (en) * | 2012-03-29 | 2013-10-23 | 三星电机株式会社 | Thin film coil and electronic device having the same |
| US8922278B2 (en) | 2010-03-04 | 2014-12-30 | Bose Corporation | Versatile audio power amplifier |
| CN104282421A (en) * | 2013-07-03 | 2015-01-14 | 艾默生过程控制流量技术有限公司 | Coil assembly, manufacturing method thereof and on-site instrument |
| CN104882260A (en) * | 2015-05-18 | 2015-09-02 | 成都锐思灵科技有限公司 | Planar transformer |
| CN108140473A (en) * | 2015-10-28 | 2018-06-08 | 陆蜂株式会社 | Transformer |
| US12160232B2 (en) | 2017-10-06 | 2024-12-03 | Allegro Microsystems, Llc | Low-latency switch drive circuit with power transfer |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002367827A (en) * | 2001-06-08 | 2002-12-20 | Shinki Kagi Kofun Yugenkoshi | Inductor using printed circuit board |
| US7352270B1 (en) | 2006-10-27 | 2008-04-01 | Itt Manufacturing Enterprises, Inc. | Printed circuit board with magnetic assembly |
| JP2008166625A (en) * | 2006-12-29 | 2008-07-17 | Matsushita Electric Works Ltd | Substrate transformer |
| JP2008177486A (en) * | 2007-01-22 | 2008-07-31 | Matsushita Electric Works Ltd | Transformer |
| JP5902503B2 (en) * | 2012-02-16 | 2016-04-13 | 株式会社日本自動車部品総合研究所 | Printed coil |
| JP2014075535A (en) | 2012-10-05 | 2014-04-24 | Toyota Industries Corp | Induction apparatus |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB700458A (en) * | 1948-10-05 | 1953-12-02 | Harold Vezey Strong | Improvements relating to the production of electric windings |
| GB868116A (en) * | 1956-07-13 | 1961-05-17 | Emi Ltd | Improvements relating to printed circuit components |
| GB993265A (en) * | 1962-04-10 | 1965-05-26 | Tokyo Denshi Seiki Kabushiki K | Electrical coils |
| GB1139795A (en) * | 1965-07-15 | 1969-01-15 | Johnson Matthey Co Ltd | Improvements in and relating to electrical components |
| GB1180923A (en) * | 1966-02-21 | 1970-02-11 | Plessey Co Ltd | Improvements relating to Electric Coil Assemblies. |
| US4873757A (en) * | 1987-07-08 | 1989-10-17 | The Foxboro Company | Method of making a multilayer electrical coil |
-
1990
- 1990-10-05 JP JP26885890A patent/JPH04144212A/en active Pending
-
1991
- 1991-10-03 GB GB9121061A patent/GB2250383A/en not_active Withdrawn
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB700458A (en) * | 1948-10-05 | 1953-12-02 | Harold Vezey Strong | Improvements relating to the production of electric windings |
| GB868116A (en) * | 1956-07-13 | 1961-05-17 | Emi Ltd | Improvements relating to printed circuit components |
| GB993265A (en) * | 1962-04-10 | 1965-05-26 | Tokyo Denshi Seiki Kabushiki K | Electrical coils |
| GB1139795A (en) * | 1965-07-15 | 1969-01-15 | Johnson Matthey Co Ltd | Improvements in and relating to electrical components |
| GB1180923A (en) * | 1966-02-21 | 1970-02-11 | Plessey Co Ltd | Improvements relating to Electric Coil Assemblies. |
| US4873757A (en) * | 1987-07-08 | 1989-10-17 | The Foxboro Company | Method of making a multilayer electrical coil |
Cited By (34)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5929733A (en) * | 1993-07-21 | 1999-07-27 | Nagano Japan Radio Co., Ltd. | Multi-layer printed substrate |
| EP0656636A1 (en) * | 1993-12-01 | 1995-06-07 | Robert Bosch Gmbh | Transformer with shielding and its use |
| GB2311417A (en) * | 1996-03-22 | 1997-09-24 | Murata Manufacturing Co | Laminated balun transformer |
| GB2311417B (en) * | 1996-03-22 | 1998-10-07 | Murata Manufacturing Co | Laminated balun transformer |
| US6388551B2 (en) | 1996-03-22 | 2002-05-14 | Murata Manufacturing Co., Ltd. | Method of making a laminated balun transform |
| DE19805914A1 (en) * | 1998-02-13 | 1999-08-19 | Thomson Brandt Gmbh | Compact planar transformer for high frequency switched mode power supplies |
| US6127911A (en) * | 1998-02-13 | 2000-10-03 | Deutsche Thomson-Brandt Gmbh | Transformer |
| GB2337863B (en) * | 1998-05-09 | 2002-08-14 | Frederick E Bott | Coil substrate |
| GB2337863A (en) * | 1998-05-09 | 1999-12-01 | Frederick E Bott | Method and means of forming a desired coil configuration |
| DE19915649A1 (en) * | 1999-04-07 | 2000-10-12 | Rohde & Schwarz | Impedance transformer for a push-pull amplifier of a short or ultra short wave transmitter |
| DE19915649B4 (en) * | 1999-04-07 | 2009-10-22 | Rohde & Schwarz Gmbh & Co. Kg | Transformer arrangement for the push-pull amplifier of a short-wave or ultra-short wave transmitter output stage |
| EP1122873A2 (en) * | 2000-02-07 | 2001-08-08 | Nihon Protector Co., Ltd. | Uninterruptible switching regulator |
| EP1122873A3 (en) * | 2000-02-07 | 2003-07-16 | Nihon Protector Co., Ltd. | Uninterruptible switching regulator |
| GB2369251B (en) * | 2000-05-22 | 2004-03-24 | Payton Ltd | Planar coil circuit |
| US6882260B2 (en) | 2000-05-22 | 2005-04-19 | Payton Ltd. | Method and apparatus for insulating a planar transformer printed circuit and lead frame windings forms |
| GB2369251A (en) * | 2000-05-22 | 2002-05-22 | Payton Ltd | Method of insulating a planar coil circuit |
| US8400788B2 (en) | 2006-12-20 | 2013-03-19 | Primozone Production Ab | Power supply apparatus for a capacitive load |
| US9126832B2 (en) | 2006-12-20 | 2015-09-08 | Primozone Production Ab | Power supply apparatus for a capacitive load |
| CN101458987B (en) * | 2007-12-11 | 2011-05-04 | 英业达股份有限公司 | Inductive device and manufacturing method thereof |
| US8922278B2 (en) | 2010-03-04 | 2014-12-30 | Bose Corporation | Versatile audio power amplifier |
| US8384478B2 (en) | 2010-03-04 | 2013-02-26 | Bose Corporation | Versatile audio power amplifier |
| US8243960B2 (en) | 2010-03-04 | 2012-08-14 | Bose Corporation | Planar audio amplifier output inductor with current sense |
| US8350537B2 (en) | 2010-03-04 | 2013-01-08 | Bose Corporation | Power supply transient response improving |
| WO2011109158A1 (en) * | 2010-03-04 | 2011-09-09 | Bose Corporation | Planar audio amplifier output inductor with current sense |
| CN103247419B (en) * | 2012-02-09 | 2016-12-14 | 成都市华森电子信息产业有限责任公司 | Manufacturing method of inductive element |
| CN103247419A (en) * | 2012-02-09 | 2013-08-14 | 成都市华森电子信息产业有限责任公司 | Inductive element and method for manufacturing the same |
| CN103366931A (en) * | 2012-03-29 | 2013-10-23 | 三星电机株式会社 | Thin film coil and electronic device having the same |
| US10103554B2 (en) | 2012-03-29 | 2018-10-16 | Samsung Electro-Mechanics Co., Ltd. | Thin film coil and electronic device having the same |
| US10122183B2 (en) | 2012-03-29 | 2018-11-06 | Samsung Electro-Mechanics Co., Ltd. | Thin film coil and electronic device having the same |
| US10483767B2 (en) | 2012-03-29 | 2019-11-19 | Wits Co., Ltd. | Thin film coil and electronic device having the same |
| CN104282421A (en) * | 2013-07-03 | 2015-01-14 | 艾默生过程控制流量技术有限公司 | Coil assembly, manufacturing method thereof and on-site instrument |
| CN104882260A (en) * | 2015-05-18 | 2015-09-02 | 成都锐思灵科技有限公司 | Planar transformer |
| CN108140473A (en) * | 2015-10-28 | 2018-06-08 | 陆蜂株式会社 | Transformer |
| US12160232B2 (en) | 2017-10-06 | 2024-12-03 | Allegro Microsystems, Llc | Low-latency switch drive circuit with power transfer |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9121061D0 (en) | 1991-11-13 |
| JPH04144212A (en) | 1992-05-18 |
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| Date | Code | Title | Description |
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| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |