GB1604531A - Interference suppression inductor for phase-controlled semi-conductor circuits - Google Patents
Interference suppression inductor for phase-controlled semi-conductor circuits Download PDFInfo
- Publication number
- GB1604531A GB1604531A GB19374/78A GB1937478A GB1604531A GB 1604531 A GB1604531 A GB 1604531A GB 19374/78 A GB19374/78 A GB 19374/78A GB 1937478 A GB1937478 A GB 1937478A GB 1604531 A GB1604531 A GB 1604531A
- Authority
- GB
- United Kingdom
- Prior art keywords
- core
- interference suppression
- inductor
- cores
- carrying
- 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.)
- Expired
Links
- 230000001629 suppression Effects 0.000 title claims abstract description 40
- 239000004065 semiconductor Substances 0.000 title claims description 18
- 239000011230 binding agent Substances 0.000 claims abstract description 14
- 229910052751 metal Inorganic materials 0.000 claims abstract description 13
- 239000002184 metal Substances 0.000 claims abstract description 13
- 238000000034 method Methods 0.000 claims abstract description 9
- 238000004804 winding Methods 0.000 claims abstract description 9
- 239000000843 powder Substances 0.000 claims abstract description 6
- 230000008901 benefit Effects 0.000 claims abstract description 3
- 230000035699 permeability Effects 0.000 claims description 21
- 230000006835 compression Effects 0.000 claims description 14
- 238000007906 compression Methods 0.000 claims description 14
- 239000006247 magnetic powder Substances 0.000 claims description 13
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 239000003990 capacitor Substances 0.000 claims description 7
- 238000000748 compression moulding Methods 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 6
- 239000002245 particle Substances 0.000 claims description 6
- 229910000640 Fe alloy Inorganic materials 0.000 claims description 4
- 238000009747 press moulding Methods 0.000 claims description 4
- 230000033228 biological regulation Effects 0.000 claims description 3
- 239000004020 conductor Substances 0.000 claims description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 2
- 230000008859 change Effects 0.000 claims description 2
- 239000000428 dust Substances 0.000 claims description 2
- 238000005516 engineering process Methods 0.000 claims description 2
- 238000009413 insulation Methods 0.000 claims description 2
- 230000001681 protective effect Effects 0.000 claims description 2
- 239000011162 core material Substances 0.000 description 60
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 11
- 230000010355 oscillation Effects 0.000 description 5
- 229910052742 iron Inorganic materials 0.000 description 4
- 238000007792 addition Methods 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000001939 inductive effect Effects 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 230000002452 interceptive effect Effects 0.000 description 2
- 238000003475 lamination Methods 0.000 description 2
- 239000000696 magnetic material Substances 0.000 description 2
- 230000003071 parasitic effect Effects 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- GOECOOJIPSGIIV-UHFFFAOYSA-N copper iron nickel Chemical compound [Fe].[Ni].[Cu] GOECOOJIPSGIIV-UHFFFAOYSA-N 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 238000009702 powder compression Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F17/00—Fixed inductances of the signal type
- H01F17/04—Fixed inductances of the signal type with magnetic core
- H01F17/06—Fixed inductances of the signal type with magnetic core with core substantially closed in itself, e.g. toroid
- H01F17/062—Toroidal core with turns of coil around it
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F17/00—Fixed inductances of the signal type
- H01F17/04—Fixed inductances of the signal type with magnetic core
Abstract
The radio suppression inductor consists of an annular core and of a winding (4), the annular core being assembled from two soft-magnetic metal-powder blanks (core elements 1, 2). One of the two core elements contains no insulating binding agent, while the other core element consists of a soft-magnetic metal powder and an insulating binding agent. The advantage of such a suppression inductor is, on the one hand, that the two core elements can be produced using the conventional pressing process for moulded cores and, on the other hand, that suppression circuits can be constructed using it, in the case of which fast switching-on processes do not exceed the required interference level. <IMAGE>
Description
(54) AN INTERFERENCE SUPPRESSION INDUCTOR FOR
PHASE-CONTROLLED SEMI-CONDUCTOR CIRCUITS
(71) We, VOGT GMBH & CO KG, Erlautal 7, D 8391 Erlau, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to an interference suppression inductor for phase-controlled semiconductor circuits.
'Phase-controlled semiconductor circuits are increasingly used in various fields of electrotechnology for controlling load currents or powers in a.c. circuits, for example for controlling motors or for regulating the brightness of light sources.
The rapid switching phenomena of such switches cause substantial interference voltages which must be attenuated to a specific permissible level by suitable suppression means over a frequency range 0.15 to 30
MHz in accordance with Regulation 0875 of Verband der Deutschen Elektro-Teckniker (vDE).
The serial connection of a toroid core inductor and a capacitor has been found to be a suitable means for interference suppression o fsuch semiconductor circuits, taking into account size and cost. This interference suppression element in the form of a voltage divider is connected in parallel with the semiconductor switch and therefore attenuates the interference signals which are produced in the switch and enter the load circuits via the supply leads.
The load current flows through the inductor and this, due to the low frequency of the supply circuit, usually 50 Hz, does not present any substantial inductive reactance at this frequency. However, the inductive reactance must be large for the high frequencies of the interference voltages, more particularly at 150 kHz, because the interference voltage is a maximum at that frequency. The inductor must therefore have the highest possible inductance of 150 kHz and accordingly the inductor core must have the highest possible permeability at this frequency. known This known interference suppression circuit suffers from an undesirable side effect in that the inductor and capacitor form an oscillating circuit which is closed when the semiconductor switch is conductive and is excited into paracitic oscillations.The frequency of the parasitic oscillations is between 5 and 20 kHz.
Superimposition of the load current and oscillating current in the semiconductor switch gives rise to current fluctuations which in turn result in unintended, interfering switching functions. For example, in light regulators they are responsible for flickering brightness fluctuations of the connected light sources.
This side effect can be avoided by adequate attenuation of the above-mentioned parasitic oscillations. It has been found that the required attenuation can be achieved only at the expense of sufficiently large losses of the inductor core since additional circuit means within the semiconductor switch, for example the inclusion of a resistor, impose an excessive load on the load circuit or excessively reduce the interference suppression action. The core material must therefore have high losses over the frequency range of 5 to 20 kHz.
The two above-mentioned requirements, namely high permeability at 150 kllz and high losses at substantially lower frequencies of 5 to 20 kHz conflict with each other if they are applied to a homogeneous soft iron magnetic material. Either the material has a wide-band characteristic and retains its permeability to the high frequencies in which case it will always have low losses at low frequencies, or it has high losses at low frequencies but this is always associated with a substantial loss of permeability at the higher frequencies.
Although a suitable compromise between both requirements is possible in some applications by using a homogenous inductor core, it is not possible to discover a suitable magnetic core material which satisfies the contradictory requirements in many cases.
This is particularly so if there is a demand for small physical dimensions with increased powers in the load circuit.
Combined inductor cores, comprising two part cores of different soft iron magnetic materials are used in such cases:
1. A "permeability carrying" part core
of wide-band characteristics with an
adequate permeability at 150 kHz:
2. A "loss carrying" part core which
has high losses at 5 to 20 kHz and
thus provides the necessary attenua
tion of the undesired paracitic oscil
lations. However it does not make
any effective contribution to the
permeability at 150 kHz.
It is also a requirement made on the interference suppression inductor that its cost should correspond to the total costs of a semiconductor switch. Since circuit elements, such as capacitors, resistors, thyristors and the like, used mainly in semiconductor circuits, have become substantially less costly in recent years it follows that the interference suppression inductor must also be inexpensive. This means that expensive materials and complex manufacturing procedures must be increasingly avoided.
German Offenlegungsschrift 2 119 950 discloses a two-part inductor whose permeability-carrying part core comprises a ferrite ring with an air gap. Transformer lamination sheets form the loss carrying part core, and due to the need for grinding the air gaps and laminating the sheets this solution to the problem calls for high expenditure in terms of manufacture. The demand for interference suppression means of moderate cost cannot therefore be satisfied. Furthermore, the laminations give rise to magnetostrictive oscillations which are audible and in many cases, for example in the case of domestic light regulators (dimmers) take the form of acoustic interference.
German Offenlegungsschrift 1183 643 also discloses an inductor with a two-part core. The permeability-carrying part core comprises a nickel-copper-iron alloy with additions of manganese, molybdenum and chromium, rolled into thin strip. The losscarrying part comprises strip or sheet of iron with additions of silicon or aluminum.
The compositions of the alloys for the permeability-carrying part core is selected so that magnetostriction is very low. This eliminates the disadvantage of interfering noise but the alloys in use, containing between 74 and 84% of nickel, rolled into strip, are too expensive as core material and do not therefore permit the construction of a low-cost interference suppression conductor.
German Offenlegungsschrift 2 505 080 also contains proposals for a two-part inductor core in which expensive materials can be avoided. The permeability carrying part in this case comprises iron powder which is compression moulded with an insulating binder. The loss-carrying part of the core is formed by annular winding of iron wire which is inserted into the mould prior to compression moulding so that after compression moulding it is embedded in the annular core and is surrounded on all sides by iron powder. This solution to the problem undoubtedly results in a reduction of costs in terms of the materials used, but manufacture and piece by piece insertion of the wire coil represent steps which must be performed in addition to the simple powder compression and call for additional devices.
More particularly, iron powder must be poured into the press mould before and after insertion of the wire core, i.e. filing takes place in two phases. Furthermore a device is required for producing and for centrally inserting the wire coils.
According to the invention there is provided an interference suppression inductor for phase-controlled semiconductor switches comprising a toroid core formed of a first permeability carrying core part, and a second loss carrying core part, an insulating winding around said toroid core, said first and second core parts being each compression moulded from metal magnetic powder characterised in that said second core part is compression moulded from metal magnetic powder without the use of insulating binders, and said first core part is compression moulded with insulating binders in the proportion of 0.15,ó to 0.45% by weight.
The metal magnetic powder in the first and second core parts may comprise particle sizes between 10 and 600 ,um.
Preferably the volumetric ratio of the loss carrying to the permeability carrying core part is in the range 0.5 to 1.5.
The second loss carrying core part may be subjected to heat treatment at temperatures of up to 2000 C.
Finally the metal magnetic powder employed may be a soft iron alloy powder.
Thus compression moulding of commercial and inexpensive soft magnetic powder grades with particles sizes between 10 and 600 ,am without the addition of insulating binders, makes it possible to produce loss carrying part cores so as to ensure the required high attenuation in the frequency range of 5 to 20 kHz in combination with a permeability carrying part core. The properties of the loss carrying core part can be influenced and adjusted to desired values by the moulding pressure, the particle size and particle size distribution of the powder and by light heat treatment. It has been found that the electromagnetic properties of such cores, more particularly the losses over the region of 5 to 20 kHz, can be maintained within the tolerances which are required for mass production.It has also been found that the mechanical strength of the cores which are compression moulded without binder, is fully adequate and differs merely insignificantly from the mechanical strength of the cores which are normally used as dust cores with binders in inductors.
The method according to the invention therefore makes it possible to produce the loss carrying part cores for interference suppression conductors by means of the same simple compression moulding prodedure as that used for the permeability carrying part cores, in the same operation and in the same press mould without any additional steps, a feature resulting in a substantial simplification of the manufacturing process.
It is an important advantage of the method that permeability and losses of the combined two-part core can be influenced not only by the above-mentioned factors of press moulding technology and heat treatment of the loss carrying part core but also by the volumetric ratio of the two part cores. In terms of manufacturing technique this can be achieved very simply by appropriate selection of the corresponding heights of the part cores during press moulding. A change of volumetric ratios can be desirable if two capacitors with two different capacitance values are used in a semiconductor switch for interference suppression. The larger capacitance value calls for a higher attenuation at 5 to 20 kHz and the inductance at
150 kHz can be lower. The attenuation for smaller capacitance values on the other hand
can be lower but a higher inductance is required at 150 kHz.The inductor properties are adapted to different requirements simply by setting up of suitable compression moulding heights when the two part cores are produced.
The two part cores are assembled and together are coated with an insulated protective film in known manner and are then wound. The invention will now be described by way of example with reference to the sole accompanying drawing which shows an interference suppression inductor according to an embodiment of the invention.
The suppression inductor shown in the drawing has a two part core 1 and 2 both of which are together coated with an insulation 3. The inductor is provided with a winding 4. The inductor shown is an embodiment suitable as a brightness regulator or dimmer for controlling power between 60 and 600 W. The external diameter of the combined and coated cores is 39 mm, the internal diameter is 20 mm and the height is 8.5 mm. The volumetric ratio of the permeability carrying part core to the loss
carrying part core in this example is 1.5.
The winding comprises 140 turns of emamelled copper wire having a diameter of 0.75 mm. When used in conjunction with a capacitor having a capacitance of 0.22 uF, this inductor will suppress the semiconductor switch so as to maintain the desired interference suppression grade N comply with
VDE Regulation 0875. The inductor according to the invention therefore satisfies the requirements made upon it although only inexpensive materials and greatly simplified manufacturing procedures are employed.
WHAT WE CLAIM IS:- 1. An interference suppression inductor for phase-controlled semiconductor switches comprising a toroid core formed of a first permeability carrying core part, and a second loss carrying core part, an insulating winding around said toroid core, said first and second core parts being each compression moulded from metal magnetic powder characterised in that said second core part is compression moulded from metal magnetic powder without the use of insulating binders, and said first core part is compression moulded with insulating binders in the proportion of 0.15% to 0.45% by weight.
2. An interference suppression inductor as claimed in Claim 1 wherein metal magnetic powder with particle sizes between 10 and 600 om is used for said first and second core parts.
3. An interference suppression inductor according to any preceding claim wherein the volumetric ratio of the loss carrying to the permeability carrying core part is in the range 0.5 to 1.5.
4. An interference suppression inductor according to any preceding claim wherein the loss carrying part core is subjected to heat treatment at temperatures of up to 200"C.
5. An interference suppression inductor according to any preceding claim wherein the metal magnetic powder is a soft iron alloy powder.
6. An interference suppression inductor according to any one of Claims 1 to 5 wherein said first and second core parts are compression moulded in the same press mould.
7. An interference suppression inductor as claimed in any preceding claim and substantially as hereinbefore described with reference to the drawing.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (7)
- **WARNING** start of CLMS field may overlap end of DESC **.that the mechanical strength of the cores which are compression moulded without binder, is fully adequate and differs merely insignificantly from the mechanical strength of the cores which are normally used as dust cores with binders in inductors.The method according to the invention therefore makes it possible to produce the loss carrying part cores for interference suppression conductors by means of the same simple compression moulding prodedure as that used for the permeability carrying part cores, in the same operation and in the same press mould without any additional steps, a feature resulting in a substantial simplification of the manufacturing process.It is an important advantage of the method that permeability and losses of the combined two-part core can be influenced not only by the above-mentioned factors of press moulding technology and heat treatment of the loss carrying part core but also by the volumetric ratio of the two part cores. In terms of manufacturing technique this can be achieved very simply by appropriate selection of the corresponding heights of the part cores during press moulding. A change of volumetric ratios can be desirable if two capacitors with two different capacitance values are used in a semiconductor switch for interference suppression. The larger capacitance value calls for a higher attenuation at 5 to 20 kHz and the inductance at150 kHz can be lower. The attenuation for smaller capacitance values on the other hand can be lower but a higher inductance is required at 150 kHz.The inductor properties are adapted to different requirements simply by setting up of suitable compression moulding heights when the two part cores are produced.The two part cores are assembled and together are coated with an insulated protective film in known manner and are then wound. The invention will now be described by way of example with reference to the sole accompanying drawing which shows an interference suppression inductor according to an embodiment of the invention.The suppression inductor shown in the drawing has a two part core 1 and 2 both of which are together coated with an insulation 3. The inductor is provided with a winding 4. The inductor shown is an embodiment suitable as a brightness regulator or dimmer for controlling power between 60 and 600 W. The external diameter of the combined and coated cores is 39 mm, the internal diameter is 20 mm and the height is 8.5 mm. The volumetric ratio of the permeability carrying part core to the loss carrying part core in this example is 1.5.The winding comprises 140 turns of emamelled copper wire having a diameter of 0.75 mm. When used in conjunction with a capacitor having a capacitance of 0.22 uF, this inductor will suppress the semiconductor switch so as to maintain the desired interference suppression grade N comply with VDE Regulation 0875. The inductor according to the invention therefore satisfies the requirements made upon it although only inexpensive materials and greatly simplified manufacturing procedures are employed.WHAT WE CLAIM IS:- 1. An interference suppression inductor for phase-controlled semiconductor switches comprising a toroid core formed of a first permeability carrying core part, and a second loss carrying core part, an insulating winding around said toroid core, said first and second core parts being each compression moulded from metal magnetic powder characterised in that said second core part is compression moulded from metal magnetic powder without the use of insulating binders, and said first core part is compression moulded with insulating binders in the proportion of 0.15% to 0.45% by weight.
- 2. An interference suppression inductor as claimed in Claim 1 wherein metal magnetic powder with particle sizes between 10 and 600 om is used for said first and second core parts.
- 3. An interference suppression inductor according to any preceding claim wherein the volumetric ratio of the loss carrying to the permeability carrying core part is in the range 0.5 to 1.5.
- 4. An interference suppression inductor according to any preceding claim wherein the loss carrying part core is subjected to heat treatment at temperatures of up to 200"C.
- 5. An interference suppression inductor according to any preceding claim wherein the metal magnetic powder is a soft iron alloy powder.
- 6. An interference suppression inductor according to any one of Claims 1 to 5 wherein said first and second core parts are compression moulded in the same press mould.
- 7. An interference suppression inductor as claimed in any preceding claim and substantially as hereinbefore described with reference to the drawing.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19772721967 DE2721967A1 (en) | 1977-05-14 | 1977-05-14 | SPARK CONDUCTORS FOR PHASE-GATE CONTROLLED SEMI-CONDUCTOR CIRCUITS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1604531A true GB1604531A (en) | 1981-12-09 |
Family
ID=6009037
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB19374/78A Expired GB1604531A (en) | 1977-05-14 | 1978-05-12 | Interference suppression inductor for phase-controlled semi-conductor circuits |
Country Status (9)
| Country | Link |
|---|---|
| AT (1) | AT376518B (en) |
| CH (1) | CH630199A5 (en) |
| DE (1) | DE2721967A1 (en) |
| DK (1) | DK210678A (en) |
| FI (1) | FI72404C (en) |
| FR (1) | FR2390818B1 (en) |
| GB (1) | GB1604531A (en) |
| IT (1) | IT7823327A0 (en) |
| SE (1) | SE443680B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1288975A3 (en) * | 2001-08-29 | 2003-04-09 | Matsushita Electric Industrial Co., Ltd. | Magnetic device, method for manufacturing the same and power supply module equipped with the same |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0098285B2 (en) † | 1982-01-15 | 1993-11-03 | Minitronics Pty. Ltd. | Electronic high frequency controlled device for operating gas discharge lamps |
| EP0351861A1 (en) * | 1988-07-21 | 1990-01-24 | Siemens Aktiengesellschaft | Inductive component, especially a transformer |
| DE102017113637A1 (en) * | 2017-06-21 | 2018-12-27 | Insta Gmbh | Phase control |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3663913A (en) * | 1967-12-22 | 1972-05-16 | Tohoku Metal Ind Ltd | Core coil having a improved temperature characteristic |
| DE2058509C3 (en) * | 1970-11-27 | 1975-07-03 | Siemens Ag | Radio interference suppression choke against impulse-like interference voltages |
| DE2119950C3 (en) * | 1971-04-23 | 1975-06-05 | Siemens Ag, 1000 Berlin Und 8000 Muenchen | Radio interference suppression choke |
| DE2505080B2 (en) * | 1975-02-07 | 1979-04-26 | Goetz-Udo 6391 Graevenwiesbach Hartmann | Radio interference suppression choke and process for their manufacture |
-
1977
- 1977-05-14 DE DE19772721967 patent/DE2721967A1/en not_active Withdrawn
-
1978
- 1978-05-11 CH CH516178A patent/CH630199A5/en not_active IP Right Cessation
- 1978-05-12 FR FR7814265A patent/FR2390818B1/en not_active Expired
- 1978-05-12 IT IT7823327A patent/IT7823327A0/en unknown
- 1978-05-12 SE SE7805525A patent/SE443680B/en not_active IP Right Cessation
- 1978-05-12 GB GB19374/78A patent/GB1604531A/en not_active Expired
- 1978-05-12 FI FI781513A patent/FI72404C/en not_active IP Right Cessation
- 1978-05-12 AT AT0346378A patent/AT376518B/en not_active IP Right Cessation
- 1978-05-12 DK DK210678A patent/DK210678A/en not_active Application Discontinuation
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1288975A3 (en) * | 2001-08-29 | 2003-04-09 | Matsushita Electric Industrial Co., Ltd. | Magnetic device, method for manufacturing the same and power supply module equipped with the same |
| US6768409B2 (en) | 2001-08-29 | 2004-07-27 | Matsushita Electric Industrial Co., Ltd. | Magnetic device, method for manufacturing the same, and power supply module equipped with the same |
Also Published As
| Publication number | Publication date |
|---|---|
| SE7805525L (en) | 1978-11-15 |
| CH630199A5 (en) | 1982-05-28 |
| ATA346378A (en) | 1984-04-15 |
| FI72404C (en) | 1987-05-11 |
| FI72404B (en) | 1987-01-30 |
| FR2390818A1 (en) | 1978-12-08 |
| FR2390818B1 (en) | 1986-04-18 |
| DE2721967A1 (en) | 1978-11-16 |
| SE443680B (en) | 1986-03-03 |
| AT376518B (en) | 1984-11-26 |
| DK210678A (en) | 1978-11-15 |
| FI781513A (en) | 1978-11-15 |
| IT7823327A0 (en) | 1978-05-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI579867B (en) | A dust core, a method for manufacturing the dust core, an electronic / electrical component provided with the dust core, and an electronic / electrical device to which the electronic / electrical component is mounted | |
| JPH09120926A (en) | High-current thin inductor and manufacture thereof | |
| JPH09129435A (en) | Coupled magnetic core | |
| JPH0696941A (en) | Partial gap magnetic core device | |
| GB2044550A (en) | Case inductive circuit components | |
| WO2016152578A1 (en) | Inductor and protection circuit | |
| US20200168389A1 (en) | Transformer and Switch-Mode Power Supply | |
| US5635828A (en) | Active filter circuit and power supply apparatus including same | |
| JP2006332245A (en) | Coil component | |
| GB1604531A (en) | Interference suppression inductor for phase-controlled semi-conductor circuits | |
| JP2006319020A (en) | Inductance component | |
| KR101097117B1 (en) | Compact Inductor Core Having Noise Reduction Structure and Inductor Using the Inductor Core | |
| CN212136184U (en) | Low-loss high-power common mode inductor | |
| JPH06112034A (en) | Winding integrated magnetic element and manufacture thereof | |
| JP2021158148A (en) | Powder magnetic core | |
| WO2007055078A1 (en) | Power inductor | |
| JP2001237128A (en) | Shell type power transformer and power converter using the same | |
| JPS6215030B2 (en) | ||
| SU1629921A1 (en) | Magnetic circuit mainly for wideband reactor | |
| JP2001115201A (en) | Alloy powder for high frequency reactor and high frequency reactor using the same | |
| JPH1064628A (en) | Abnormal current suppressing device of electric parts | |
| JPH0456111A (en) | Inductance part and its preparation | |
| Hempstead et al. | 13 Magnetic-Core | |
| JP2001223106A (en) | Dust core and high-frequency reactor using the same | |
| JPS6320813A (en) | Noise filter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| PCNP | Patent ceased through non-payment of renewal fee |