IE51834B1 - A laminated magnetic circuit with fixed air gap and procedure for adjustment thereof - Google Patents

A laminated magnetic circuit with fixed air gap and procedure for adjustment thereof

Info

Publication number
IE51834B1
IE51834B1 IE1423/81A IE142381A IE51834B1 IE 51834 B1 IE51834 B1 IE 51834B1 IE 1423/81 A IE1423/81 A IE 1423/81A IE 142381 A IE142381 A IE 142381A IE 51834 B1 IE51834 B1 IE 51834B1
Authority
IE
Ireland
Prior art keywords
magnetic circuit
air gap
laminated magnetic
fixed air
procedure
Prior art date
Application number
IE1423/81A
Other versions
IE811423L (en
Inventor
Gilles Desombre
Marc Dujardin
Gerard Haroux
Original Assignee
Clarel Sa
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 Clarel Sa filed Critical Clarel Sa
Publication of IE811423L publication Critical patent/IE811423L/en
Publication of IE51834B1 publication Critical patent/IE51834B1/en

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00Details of transformers or inductances, in general
    • H01F27/24Magnetic cores
    • H01F27/245Magnetic cores made from sheets, e.g. grain-oriented
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01FMAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F3/00Cores, Yokes, or armatures
    • H01F3/10Composite arrangements of magnetic circuits
    • H01F3/14Constrictions; Gaps, e.g. air-gaps

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Composite Materials (AREA)
  • Chemical & Material Sciences (AREA)
  • Coils Or Transformers For Communication (AREA)
  • Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
  • Paper (AREA)
  • Manufacturing Of Magnetic Record Carriers (AREA)
  • Control Of Electric Motors In General (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)
  • Magnetic Heads (AREA)
  • Switches That Are Operated By Magnetic Or Electric Fields (AREA)
  • Magnetically Actuated Valves (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
  • Magnetic Treatment Devices (AREA)
  • Electron Tubes For Measurement (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
  • Supporting Of Heads In Record-Carrier Devices (AREA)
  • Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
  • Fittings On The Vehicle Exterior For Carrying Loads, And Devices For Holding Or Mounting Articles (AREA)
  • Traffic Control Systems (AREA)

Abstract

1. Laminated magnetic circuit with air gap, comprising and E-shaped part and an I-shaped part (4), and wherein the lenght of the end bars (2) of the E part determines the depth of the air gap opposite the central bar (3) of this E part, characterized in that the side of the I part (4) which rests on the end bars (2) of the E part forms an obtuse angle (alpha) wiht the sides at the end of the part I part (4), and in that the two end bars (2) of the E part each have a prolongation (5) and these are arranged at a distance from one another corresponding to the lenght of the I part (4), so as to fit the shape of the said obtuse angle (alpha) in engaging about the I part (4).

Description

The present invention concerns a laminated magnetic circuit with fixed air gap, composed of an E-shaped part and an I-shaped part in which the length of the outer limbs of the E-part determines the width of the air gap at the face of the middle limb of this E-part.
The object of the invention is to provide such a laminated circuit suitable, for example, as a ballast for fluorescent lamps having high reliability to maintain its reactance value during its life and permitting easy adjustment of the reactance value at the time of manufacture.
According to the present invention there is provided a laminated circuit having a fixed air-gap comprising an E-shaped part and an Ishaped part in which the length of the outer limbs of the E-part determines the width of the air gap from the face of the middle limb of this E-part wherein the side of the I-part resting on the outer limbs of the E-part forms an obtuse angle with the sides of the ends of the I-part, and the two outer limbs of the E-part are each formed with an extension spaced apart the length of the I-part for enclosing the I-part and conforming to the shape of the said obtuse angle.
The invention is hereinafter described with reference to the accompanying drawings showing an embodiment thereof by way of example.
Figure 1 of the drawings is a sectional view of a magnetic circuit according to the invention, taken between two laminae of the E-part and I-part.
Figure 2 is an elevation of a stamped-out sheet.
In a casing 1,1', which is known, for example, by published Patent Specification No. 1,638,339, comprising two outer limbs 2 and a very short middle limb 3, the width of the inter-space is bridged over by a part 4 of the I-part. The side of the part 4 resting on the limbs 2 forms with the sides at the end of the part 4 an obtuse angle a. The two limbs 2 each have an extension 5. The two extensions 5 are arranged apart a distance equal to the length of the part 4 so as to hold the part 4 between them, making a contact angle of a therewith. By this arrangement the part 4 is retained correctly centered with respect to the E-part. The dimensions are chosen in such a manner that a bearing is assured between the extremities of the part 4 of the E-part and the parts of the limbs 2 parallel to the extremities of the middle limb and that a light wedging may be assured between the part 4 and the inclined parts of the extensions 5 in such a way that the principal flux finds a sufficient path and that the dispersion of the flux at the place of contact between the part 4 and the limbs 2 may be reduced to a very weak value. Moreover the lines of force of the dispersed flux do not then traverse the casing 1 and do not produce sounds. The obtuse anqle a is for example from 91° to 120°. It is chosen relatively near to a right-angle in order to avoid the part 4 from becoming detached from the E-part.
As the part 4 is maintained centrally with respect to the E-part it is easy to adjust the mean value of the air gap or what amounts to the value of the reactance as it affects the magnetic circuit of a ballast induction coil, for example. In order to do this it is sufficient to deform one or more laminae of the part 4 of the E-part at one or more places by a limited number of punctiform depressions where it is near to the limb 3.
The procedure involving punctiform depressions, equidistant apart or not, does not permit the introduction of a plastically deformable distancing material into the clearance space, as for example aluminium, as would be the case for example if the whole of the I-part was made the subject of a depression To facilitate the punctiform depressions the section of the laminae of the part 4 of the I-part facing the limb 3 may be weakened, especially by punching out apertures 6. It may be noted here that these apurtures 6 need not be used in assembling the laminations of the part 4. If it is desired to use the apertures 6 in the assembling of the laminations of the part 4, the diameter of the apertures 6 may be sensibly greater than the diameter of a pin which passes through them to enable the puncti15 form depressions of certain of the laminae to be accurately positioned. 4s the depressions do not have to be made on all the laminae, the air gap may be a little irregular. The inconvenience of these irregularities may be avoided by choosing, for example, a series of equidistant places where the depressions are disposed.
When the magnetic circuit described is used in a ballast according to Trench Patent No. 1,291,362, the impregnation ducts are left not only along the clearance space and the coil, but also the perforations 6 which provide an impregnation duct at a particularly critical place which could be the source of sounds, because they are opposite to the air gap. The other impregnation ducts are arranged between the ends of the limbs 2 and the casing where all pressure in the direction of the part 4 is avoided so as not to affect the principal contact between the E and I parts.
The invention enables very great accuracy in the air gap from the start.
In fact, as shown by the view of stamped-out lamination 8, Figure 2, the faces defining the air gap are cut by being punched out (cross-hatched surface 9) much more precisely than by shearing with reference to the line 10.

Claims (4)

1. A laminated magnetic circuit having a fixed air-gap comprising an E-shaped part and an I-shaped part in which the length of the outer limbs of the E-part determines the width of the air gap from the 5 face of the middle limb of this E-part wherein the side of the I-part resting on the outer limbs of the E-part forms an obtuse angle with the sides of the ends of the I-part, and the two outer limbs of the E-part are each formed with an extension spaced apart the length of the I-part for enclosing the I-part and conforming to the shape of the said obtuse 10 angle.
2. A magnetic circuit according to claim 1 wherein the I-part comprises a weakening in its cross-section, preferably an aperture opposite the middle limb of the E-part.
3. A method of adjusting the air gap of a magnetic circuit according 15 to Claim 1 or 2, wherein one or more of the laminae of the I-part is deformed by a limited number of punctiform depressions at one or more places in proximity to the middle limb of the E-part.
4. A laminated magnetic circuit constructed substantially as described herein with reference to the accompanying drawings.
IE1423/81A 1980-06-30 1981-06-26 A laminated magnetic circuit with fixed air gap and procedure for adjustment thereof IE51834B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP80400979A EP0042898B1 (en) 1980-06-30 1980-06-30 Laminated magnetic circuit with air gap, and method of adjusting the air gap

Publications (2)

Publication Number Publication Date
IE811423L IE811423L (en) 1981-12-30
IE51834B1 true IE51834B1 (en) 1987-04-15

Family

ID=8187379

Family Applications (1)

Application Number Title Priority Date Filing Date
IE1423/81A IE51834B1 (en) 1980-06-30 1981-06-26 A laminated magnetic circuit with fixed air gap and procedure for adjustment thereof

Country Status (10)

Country Link
EP (1) EP0042898B1 (en)
AT (1) ATE9749T1 (en)
DE (1) DE3069353D1 (en)
DK (1) DK244581A (en)
ES (1) ES272474Y (en)
FI (1) FI75446C (en)
GR (1) GR74360B (en)
IE (1) IE51834B1 (en)
NO (1) NO812219L (en)
PT (1) PT73282B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4480377A (en) * 1982-09-27 1984-11-06 General Motors Corporation Method of making an ignition coil core
DE19645098C2 (en) * 1996-11-01 2000-09-21 Vossloh Schwabe Gmbh Choke and process for its manufacture

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1054551A (en) * 1954-02-11
FR942323A (en) * 1941-01-28 1949-02-04 Thomson Houston Comp Francaise Improvements in the construction of magnetic cores
US3071744A (en) * 1954-12-14 1963-01-01 Advance Transformer Co Electromagnetic core construction
US3219957A (en) * 1957-12-03 1965-11-23 Advance Transformer Co Core for electromagnetic device
DE1638944A1 (en) * 1967-02-09 1970-05-14 Waasner B Core sheet with two sheet metal parts
DE1613628A1 (en) * 1967-03-20 1970-07-30 Blum Eisen & Metallind Two-part iron core, especially for transformers
DE1929566A1 (en) * 1968-06-27 1970-06-18 Idec Izumi Corp Transformer core and process for its manufacture
GB1345523A (en) * 1970-09-10 1974-01-30 Friedland Ltd V E Doggart J Sk Transformer laminations

Also Published As

Publication number Publication date
ES272474U (en) 1984-03-01
ES272474Y (en) 1984-10-01
IE811423L (en) 1981-12-30
GR74360B (en) 1984-06-27
FI75446B (en) 1988-02-29
PT73282A (en) 1981-07-01
FI812017L (en) 1981-12-31
DK244581A (en) 1981-12-31
EP0042898A1 (en) 1982-01-06
ATE9749T1 (en) 1984-10-15
DE3069353D1 (en) 1984-11-08
FI75446C (en) 1988-06-09
NO812219L (en) 1982-01-04
PT73282B (en) 1982-07-01
EP0042898B1 (en) 1984-10-03

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