EP0192307B1 - Transformer comprising an air gap - Google Patents

Transformer comprising an air gap Download PDF

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Publication number
EP0192307B1
EP0192307B1 EP19860200234 EP86200234A EP0192307B1 EP 0192307 B1 EP0192307 B1 EP 0192307B1 EP 19860200234 EP19860200234 EP 19860200234 EP 86200234 A EP86200234 A EP 86200234A EP 0192307 B1 EP0192307 B1 EP 0192307B1
Authority
EP
European Patent Office
Prior art keywords
air gap
transformer
gauze
core
cement
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
Application number
EP19860200234
Other languages
German (de)
French (fr)
Other versions
EP0192307A1 (en
Inventor
Jan Henricus Maria Hopmans
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
Koninklijke Philips Electronics NV
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Philips Gloeilampenfabrieken NV, Koninklijke Philips Electronics NV filed Critical Philips Gloeilampenfabrieken NV
Publication of EP0192307A1 publication Critical patent/EP0192307A1/en
Application granted granted Critical
Publication of EP0192307B1 publication Critical patent/EP0192307B1/en
Expired legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F3/00—Cores, Yokes, or armatures
    • H01F3/10—Composite arrangements of magnetic circuits
    • H01F3/14—Constrictions; Gaps, e.g. air-gaps

Definitions

  • the invention relates to a transformer comprising a ferromagnetic core in which there is provided at least one air gap which is filled with a non-ferromagnetic material comprising a spacer which is embedded in cement.
  • a transformer comprising a ferromagnetic core in which there is provided at least one air gap which is filled with a non-ferromagnetic material comprising a spacer which is embedded in cement.
  • a spacer in the known device is formed by a quantity of hard grains, for example of glass, which are mixed with the cement. The diameter of the grains determines the width of the air gap.
  • the object of the invention to propose a device of the kind set forth in which the glass grains are replaced by a spacer which is less expensive and easier to procure.
  • the device in accordance with the invention is characterized in that the spacer consists of a plate made of gauze.
  • Gauze is usually readily available at an attractive price because it is also manufactured for other purposes.
  • a very suitable gauze is the kind which is customarily used for silk-screening.
  • Figure 1 shows a transformer comprising a ferromagnetic core 1, for example of ferrite, which consists of two parts, the transformer further comprising a primary coil 3 and a secondary coil 5. At the area of the primary coil 3 the core 1 is interrupted by an air gap 7 (denoted by broken lines).
  • FIG. 2 is a detailed longitudinal sectional view of the air gap 7 together with the surrounding parts of the primary coil 3 and the core 1.
  • the air gap 7 has a predetermined width d. This width equals the thickness of a gauze plate 9 which is situated in the air gap 7.
  • the gauze is embedded in a layer of cement 11.
  • the plate 9 which is drenched in the cement 11 is arranged between the two parts of the core which are subsequently pressed together and the cement is allowed to set, for example by heating.
  • the diameter of the wires 13 constituting the gauze of the plate 9 then automatically determines the thickness d of the air gap without it being necessary to measure and adjust the spacing of the two parts of the core during manufacture.
  • the thickness d is slightly smaller than twice the diameter of the wires 13 because the wires 13 are slightly compressed at the points of contact.
  • a very suitable type of gauze is the type which is customarily used for silk-screening, for example Estal Mono PE 275 which is made by Schweizerische Seidengazefabrik A.G., Thai.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Composite Materials (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Coils Or Transformers For Communication (AREA)
  • Inspection Of Paper Currency And Valuable Securities (AREA)
  • Developing Agents For Electrophotography (AREA)
  • Printing Plates And Materials Therefor (AREA)
  • Soft Magnetic Materials (AREA)

Description

  • The invention relates to a transformer comprising a ferromagnetic core in which there is provided at least one air gap which is filled with a non-ferromagnetic material comprising a spacer which is embedded in cement. Such a device is known from GB-A-1,246,458. The spacer in the known device is formed by a quantity of hard grains, for example of glass, which are mixed with the cement. The diameter of the grains determines the width of the air gap.
  • It has been found in practice that the manufacture of glass grains having the necessary dimensional precision is comparatively difficult. Moreover, a manufacturer of ferromagnetic cores for transformers or choke coils uses only comparatively small quantities of glass grains, even when large numbers of cores are manufactured. Consequently, the manufacture of glass grains with the necessary precision is not profitable, so that such glass grains are expensive and often difficult to procedure.
  • It is the object of the invention to propose a device of the kind set forth in which the glass grains are replaced by a spacer which is less expensive and easier to procure. To achieve this, the device in accordance with the invention is characterized in that the spacer consists of a plate made of gauze.
  • Gauze is usually readily available at an attractive price because it is also manufactured for other purposes. A very suitable gauze is the kind which is customarily used for silk-screening.
  • The invention will be described in detail hereinafter with reference to the accompanying drawing. Therein:
    • Figure 1 is a diagrammatic side elevation of an embodiment of a transformer in accordance with the invention, and
    • Figure 2 is a longitudinal sectional view at an increased scale of the part of the core of the transformer shown in Figure 1 in which the air gap is situated.
  • Figure 1 shows a transformer comprising a ferromagnetic core 1, for example of ferrite, which consists of two parts, the transformer further comprising a primary coil 3 and a secondary coil 5. At the area of the primary coil 3 the core 1 is interrupted by an air gap 7 (denoted by broken lines).
  • Figure 2 is a detailed longitudinal sectional view of the air gap 7 together with the surrounding parts of the primary coil 3 and the core 1. The air gap 7 has a predetermined width d. This width equals the thickness of a gauze plate 9 which is situated in the air gap 7. The gauze is embedded in a layer of cement 11. During the manufacture of the core 1 the plate 9 which is drenched in the cement 11 is arranged between the two parts of the core which are subsequently pressed together and the cement is allowed to set, for example by heating. The diameter of the wires 13 constituting the gauze of the plate 9 then automatically determines the thickness d of the air gap without it being necessary to measure and adjust the spacing of the two parts of the core during manufacture. The thickness d is slightly smaller than twice the diameter of the wires 13 because the wires 13 are slightly compressed at the points of contact. A very suitable type of gauze is the type which is customarily used for silk-screening, for example Estal Mono PE 275 which is made by Schweizerische Seidengazefabrik A.G., Thai.

Claims (2)

1. A transformer comprising a ferromagnetic core in which there is provided at least one air gap which is filled with a non-ferromagnetic material comprising a spacer which is embedded in cement, characterized in that the spacer consists of a plate made of gauze.
2. A transformer as claimed in Claim 1, characterized in that the plate is made of a type of gauze which is customarily used for silk-screening.
EP19860200234 1985-02-19 1986-02-18 Transformer comprising an air gap Expired EP0192307B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL8500463 1985-02-19
NL8500463A NL8500463A (en) 1985-02-19 1985-02-19 TRANSFORMER WITH AIR SLOT.

Publications (2)

Publication Number Publication Date
EP0192307A1 EP0192307A1 (en) 1986-08-27
EP0192307B1 true EP0192307B1 (en) 1989-06-07

Family

ID=19845550

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19860200234 Expired EP0192307B1 (en) 1985-02-19 1986-02-18 Transformer comprising an air gap

Country Status (4)

Country Link
EP (1) EP0192307B1 (en)
JP (1) JPS61189608A (en)
DE (2) DE8603702U1 (en)
NL (1) NL8500463A (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3908224A1 (en) * 1989-03-14 1990-09-20 Vogt Electronic Ag COMBINED EMISSION CONTROLLER TO REMOVE SYMMETRICAL AND ASYMMETRICAL INTERFERENCE
DE4228642A1 (en) * 1992-08-28 1994-03-03 Tridonic Bauelemente Gmbh Dorn Choke impedance adjustment method
JPH0722258A (en) * 1993-06-30 1995-01-24 Matsushita Electric Ind Co Ltd Reactor and manufacture thereof
US5926946A (en) * 1994-12-28 1999-07-27 Matsushita Electric Industrial Co., Ltd. Method for manufacturing reactor
DE19833190A1 (en) * 1998-07-23 2000-01-27 Bayerische Motoren Werke Ag ignition coil
KR101132086B1 (en) * 2009-06-29 2012-04-02 울산대학교 산학협력단 Implant having controlled cell adhesion and proliferation and method for manufacturing the same

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2494180A (en) * 1946-04-06 1950-01-10 Acme Electric Corp Laminated reactor
JPS5574111A (en) * 1978-11-29 1980-06-04 Hitachi Ltd Transformer
JPS55151307A (en) * 1979-05-14 1980-11-25 Victor Co Of Japan Ltd Closed magnetic circuit device

Also Published As

Publication number Publication date
EP0192307A1 (en) 1986-08-27
DE3663868D1 (en) 1989-07-13
NL8500463A (en) 1986-09-16
DE8603702U1 (en) 1986-04-10
JPS61189608A (en) 1986-08-23

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