GB708136A - Improvements in or relating to magnetic circuits comprising a highly-permeable part and a substantially flat thin permanent magnet - Google Patents

Improvements in or relating to magnetic circuits comprising a highly-permeable part and a substantially flat thin permanent magnet

Info

Publication number
GB708136A
GB708136A GB20141/51A GB2014151A GB708136A GB 708136 A GB708136 A GB 708136A GB 20141/51 A GB20141/51 A GB 20141/51A GB 2014151 A GB2014151 A GB 2014151A GB 708136 A GB708136 A GB 708136A
Authority
GB
United Kingdom
Prior art keywords
permanent magnet
airgap
edge
magnet
flux
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
GB20141/51A
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.)
Philips Electrical Industries Ltd
Original Assignee
Philips Electrical Industries Ltd
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 Electrical Industries Ltd filed Critical Philips Electrical Industries Ltd
Publication of GB708136A publication Critical patent/GB708136A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/0302—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity characterised by unspecified or heterogeneous hardness or specially adapted for magnetic hardness transitions
    • H01F1/0311—Compounds
    • H01F1/0313—Oxidic compounds
    • H01F1/0315—Ferrites
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/02—Permanent magnets [PM]
    • H01F7/0205—Magnetic circuits with PM in general
    • H01F7/021—Construction of PM
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
    • H04R9/02—Details
    • H04R9/025—Magnetic circuit
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2209/00—Details of transducers of the moving-coil, moving-strip, or moving-wire type covered by H04R9/00 but not provided for in any of its subgroups
    • H04R2209/022—Aspects regarding the stray flux internal or external to the magnetic circuit, e.g. shielding, shape of magnetic circuit, flux compensation coils

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Power Engineering (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Electromagnetism (AREA)
  • Hard Magnetic Materials (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)

Abstract

708,136. Magnetic structures. PHILIPS ELECTRICAL INDUSTRIES, Ltd. Aug. 27,1951 [April 23,1951], No. 20141/51. Class 38(2) A magnetic structure for use in magnetic filters, measuring instruments and loudspeakers comprises one or more parts 4, 5 of high permeability together with a substantially flat thin permanent magnet 1 magnetized across its thickness 9 and having a coercivity of at least 750 Oersteds and a.low-remanence (e.g. less than 5,000 Gauss), the parts of high permeability having a portion 7 in which the flux is parallel to the flux in the permanent magnet and touching the permanent magnet or spaced from it by a distance 8 which is less than one half, preferably less than one quarter the thickness 9 of the permanent magnet, there being an air gap 10 adjacent an edge of the magnet. Owing to the characteristics of the permanent magnet material, there is little leakage flux at the edge 14, but by turning up the edge of part 4, the space 8 and airgap 10 are arranged circumferentially and leakage is considerably reduced. Many other constructions are described with reference to the other figures, in some the distance 8 being zero, and the airgap being partly bounded by the permanent magnet, e.g., Fig. 10. The airgap may be between a permanent magnet and either a part of high permeability, Fig. 3, when it may be used as a braking magnet for a Ferraris meter, or another permanent magnet, Fig. 12 (not shown). Suitable materials for the permanent magnets is that sold under the name Vectolite, and those forming the subject of Specifications 590,392, 596,875 and 708,127. Specifications 708,121, 708,131, 708,132, 708,133, 708,134, 708,135, 708,137 and 708,140 also are referred to.
GB20141/51A 1951-04-23 1951-08-27 Improvements in or relating to magnetic circuits comprising a highly-permeable part and a substantially flat thin permanent magnet Expired GB708136A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL313462X 1951-04-23

Publications (1)

Publication Number Publication Date
GB708136A true GB708136A (en) 1954-04-28

Family

ID=19783713

Family Applications (1)

Application Number Title Priority Date Filing Date
GB20141/51A Expired GB708136A (en) 1951-04-23 1951-08-27 Improvements in or relating to magnetic circuits comprising a highly-permeable part and a substantially flat thin permanent magnet

Country Status (5)

Country Link
US (1) US2698917A (en)
BE (1) BE505468A (en)
CH (1) CH313462A (en)
FR (1) FR1041525A (en)
GB (1) GB708136A (en)

Families Citing this family (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2778803A (en) * 1953-02-06 1957-01-22 Aerovox Corp Magnetically hard materials
DE1011466B (en) * 1955-06-18 1957-07-04 Philips Patentverwaltung Magnet system for electroacoustic transducers
DE1020098B (en) * 1955-10-03 1957-11-28 Stepper & Co Brake magnet arrangement for a rotor disk, in particular for electricity counters
US2943246A (en) * 1956-02-28 1960-06-28 Howard C Riordan Magnetic detachable holding device
US2920253A (en) * 1956-03-06 1960-01-05 Engineered Products Company Magnetic catch
US2972745A (en) * 1956-04-17 1961-02-21 Hamilton Watch Co Electric wrist watch
US2966106A (en) * 1957-01-05 1960-12-27 Schneider Co Optische Werke Magnetic system for producing arcuate motions
US2923783A (en) * 1957-06-17 1960-02-02 Stanley F White Electro-acoustical transducer
US3095525A (en) * 1958-01-20 1963-06-25 Crucible Steel Co America Permanent magnet assembly
US3090107A (en) * 1958-07-24 1963-05-21 Sylvania Electric Prod Method of making a permanent magnet
US3022398A (en) * 1959-05-15 1962-02-20 Fluidwick Company Inc Electric control device
US3049636A (en) * 1959-06-22 1962-08-14 Chrysler Corp Magnetically driven devices
US3000016A (en) * 1960-03-03 1961-09-19 Stockwell A Ridge Magnetic securing means
DE1172384B (en) * 1960-03-03 1964-06-18 Magnetfab Bonn Gmbh Magnetic flexible layer body
US3034320A (en) * 1960-03-21 1962-05-15 Coro Inc Magnetic earring construction including means to concentrate the magnetic force
US3071939A (en) * 1960-05-27 1963-01-08 Coro Inc Magnetic earring with slidably pivoted clamp members
US3134057A (en) * 1960-07-11 1964-05-19 Sumitomo Metal Ind Magnetic circuit for the deflection of flux leakage
US3140430A (en) * 1960-07-15 1964-07-07 Radio Frequency Lab Inc Standard magnet structure with predetermined air-gap
US3173067A (en) * 1962-03-22 1965-03-09 Westinghouse Electric Corp Temperature-compensated permanent-magnet devices
US3413551A (en) * 1964-06-22 1968-11-26 Westinghouse Electric Corp Induction devices having low side thrust
US3304527A (en) * 1965-04-26 1967-02-14 Ibm Magnetic holding and aligning device
BE755398A (en) * 1969-11-28 1971-02-01 Honeywell Inc MAGNET EXCITATION ARRANGEMENT FOR A MAGNETO-SENSITIVE DEVICE, AND PROCESS FOR ACHIEVING IT
US4077242A (en) * 1976-12-15 1978-03-07 Sedley Bruce S Metal magnetic key
US5125134A (en) * 1985-12-27 1992-06-30 Tamao Morita Magnetic fastener
FR2614656B1 (en) * 1987-04-30 1989-06-16 Comadur Sa MAGNETIC ASSEMBLY DEVICE, PARTICULARLY FOR DENTAL PROSTHESIS
US4857841A (en) * 1987-12-29 1989-08-15 Eaton Corporation Proximity detector employing magneto resistive sensor in the central magnetic field null of a toroidal magnet
JP2561109B2 (en) * 1988-01-27 1996-12-04 株式会社応用技術研究所 Magnetic hook
JPH02105503A (en) * 1988-10-14 1990-04-18 Oyo Gijutsu Kenkyusho:Kk Magnetic tool for latching and locking
JP3161673B2 (en) * 1994-05-30 2001-04-25 松下電器産業株式会社 Magnetic circuit unit for micro speaker and method of manufacturing the same
JPH11275678A (en) * 1998-03-25 1999-10-08 Sony Corp Loudspeaker device
US7372968B2 (en) * 2000-11-08 2008-05-13 New Transducers Limited Loudspeaker driver
US20040005074A1 (en) * 2002-07-08 2004-01-08 Sun Technique Electric Co., Ltd. Hi-fi tweeter
US8358801B2 (en) 2007-02-12 2013-01-22 Robert Katz Magnetic circuit for electrodynamic moving voice coil actuators
US10978230B2 (en) * 2018-11-07 2021-04-13 Livivos Inc. Magnet arrangement for producing a field suitable for NMR in a concave region

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB406086A (en) * 1932-11-03 1934-02-22 Darwins Ltd Improvements in or relating to permanent magnets
FR867783A (en) * 1939-11-24 1941-11-27 Thomson Houston Comp Francaise Improvements to permanent magnets
GB549643A (en) * 1941-05-27 1942-12-01 Standard Telephones Cables Ltd Improvements in or relating to telephone transmitters and receivers

Also Published As

Publication number Publication date
FR1041525A (en) 1953-10-23
BE505468A (en)
US2698917A (en) 1955-01-04
CH313462A (en) 1956-04-15

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