US3830986A - Magnetic circuit for an electro-acoustic converter - Google Patents

Magnetic circuit for an electro-acoustic converter Download PDF

Info

Publication number
US3830986A
US3830986A US00315963A US31596372A US3830986A US 3830986 A US3830986 A US 3830986A US 00315963 A US00315963 A US 00315963A US 31596372 A US31596372 A US 31596372A US 3830986 A US3830986 A US 3830986A
Authority
US
United States
Prior art keywords
magnetic
magnetic circuit
voice coil
electro
conductive layer
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 - Lifetime
Application number
US00315963A
Other languages
English (en)
Inventor
I Yamamuro
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.)
Pioneer Corp
Original Assignee
Pioneer Electronic Corp
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 Pioneer Electronic Corp filed Critical Pioneer Electronic Corp
Application granted granted Critical
Publication of US3830986A publication Critical patent/US3830986A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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

Definitions

  • ABSTRACT An improvement in an electro-acoustic converter having a magnetic circuit with an air gap therein, the improvement including an air gap formed of a magnetic material laminated with a conductive layer having a comparatively higher magnetic resistance in the magnetic circuit, thereby increasing a magnetic resistance against a magnetic flux caused by a voice coil and acting the conductive layer as shorting rings to decrease the inductance of the voice coil, and thus eliminating the reproduction distortion caused by the magnetic non-linearity of the magnetic circuit.
  • This invention relates to a magnetic circuit for an electro-acoustic converter such as a speaker or a microphone.
  • the present invention has taken notice of the aforementioned problems and eliminates the distortion caused by the magnetic circuit.
  • the primary object of the present invention is to provide a magnetic circuit for an electro-acoustic converting device characterized in that a portion or all of the magnetic circuit elements defining an air gap have magnetically anisotropic characteristics, thereby increasing the magnetic resistance against magnetic flux caused by the voice coil and eliminating the reproduction distortion caused by the magnetic non-linearity of the magnetic circuit.
  • Another object of the present invention is to provide a magnetic circuit for an electro-acoustic converter which includes an air gap defined by magnetic parts of magnetic material laminated with a conductive layer so as to have the magnetically anisotropic character whereby the reproduction distortion caused by the inductance of the voice coil is sharply reduced.
  • FIGS. la-lc are vertical sections of conventional magnetic circuit portions for an electro-acoustic converter.
  • FIGS. 2 and 3 are vertical sections of embodiments of a magnetic circuit in accordance with the present in: vention.
  • FIG. 4 is an enlarged fragmentary sectional view schematically illustrating directions of magnetic flux of a voice coil.
  • 1 is a yoke
  • 2 is a center pole fixed in the center of the yoke l
  • 3 is a ring-shaped magnet
  • 4 is a plate fixed on the magnet 3
  • 5 is a voice coil cylinder
  • 6 is a voice coil.
  • the upper outside portion of the pole 2 and the inside portion of the plate 4 are respectively constructed with magnetic parts 7 and 8 which alternately laminate a sheet of magnetically anisotropic material or normal magnetic material 9, and a conductive layer 10 having comparatively higher magnetic resistance so as to have characteristics of magnetic anistropy.
  • the easy magnetizing axis and a hard magnetizing axis of the parts 7 and 8 are consequently directed at right angles and parallel to the voice coil 6, respectively.
  • the magnetic flux out of the magnet 3 returns to the same magnet 3 by way of the plate 4, the easy magnetizing axis of the magnetically anisotropic part 8, the air gap, the easy magnetizing axis of the magnetically anisotropic part 7, the center pole 5 and the yoke l.
  • the magnetic flux for driving the speaker passes the air gap through the same path as in the conventional magnetic circuit.
  • the total magnetic resistance of the magnetic circuit is slightly increased as compared to a conventional magnetic circuit, because the magnetic flux for driving the voice coil passes through the easy magnetizing axis of the magnetically anisotropic parts 7 and 8.
  • Magnetic flux caused by the voice coil 6 follows the path shown by dotted lines in FIG. 4, that is, the magnetic flux completes closed loops which pass along both hard magnetizing axes of the magnetically anisotropic parts 7 and 8.
  • the magnetic flux passing the magnetic anisotropic parts is limited because of the high magnetic resistance and the magnetic saturation brought about by the small magnetic flux. Consequently, the reproduction distortion due to the magnetic non-linearity of the magnetic circuit elements decreases greatly because of the weak mutual relation of the magnetic flux of the voice coil 6 and the magnetic circuit parts.
  • the resistance of the two directionalsilicon steel is higher than normal iron, the silicon steel is useful for decreasing eddy current power loss caused by the magnetic flux of the voice coil in the magnetic circuit elements.
  • the conductive layers 10 not only act as magnetic resistance members, but also act as short rings, and thus the reproduction distortion decreases because of the weak mutual relation of the inductance of the voice coil 6 and the surrounding magnetic material.
  • the magnetic circuit of the present invention is composed of laminated magnetic parts which increase the magnetic resistance against the magnetic flux caused by a voice coil.
  • the sheets of the magnetically anisotropic material are oriented such that the direction of the easy magnetizing axis is the same as the direction of the magnetic flux for driving the speaker or the microphone within the air gap. Consequently reproduction distortion is sharply reduced. Since the conductive layers are between the sheets of the magnetic material, the conductive layers function as shorting rings, the inductance of the voice coil is diminished and thus the reproduction distortion is further reduced.
  • a magnetic circuit for an electro-acoustic converter having a magnetic circuit means with an air gap therein, the improvement comprising:
  • said magnetic circuit means includes magnetically anisotropic parts composed of a magnetic material laminated with a conductive layer means.
  • said plate means comprises a magnetic material laminated with conductive layer means.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
US00315963A 1971-12-17 1972-12-18 Magnetic circuit for an electro-acoustic converter Expired - Lifetime US3830986A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP46102519A JPS5235294B2 (de) 1971-12-17 1971-12-17

Publications (1)

Publication Number Publication Date
US3830986A true US3830986A (en) 1974-08-20

Family

ID=14329584

Family Applications (1)

Application Number Title Priority Date Filing Date
US00315963A Expired - Lifetime US3830986A (en) 1971-12-17 1972-12-18 Magnetic circuit for an electro-acoustic converter

Country Status (3)

Country Link
US (1) US3830986A (de)
JP (1) JPS5235294B2 (de)
DE (1) DE2261501C3 (de)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3922501A (en) * 1971-12-17 1975-11-25 Pioneer Electronic Corp Moving voice coil electro-acoustic converter with laminated magnetically anisotropic poles
US4259550A (en) * 1978-04-15 1981-03-31 Yoshiro Nakamatsu Acoustic device with floating vibrating means
EP0029266A1 (de) * 1979-11-20 1981-05-27 Koninklijke Philips Electronics N.V. Magnetsystem für einen elektroakustischen Wandler
US4378471A (en) * 1981-02-18 1983-03-29 Ibuki Kogyo Co., Ltd. Horn speaker with linear grooves in a front surface of a pole piece of a yoke
US5321762A (en) * 1991-08-05 1994-06-14 Aura Systems, Inc. Voice coil actuator
US5381483A (en) * 1993-04-05 1995-01-10 Commonwealth Of Puerto Rico Minimal inductance electrodynamic transducer
WO2001006523A2 (en) * 1999-07-20 2001-01-25 New Transducers Limited Magnet assembly
EP1072168A1 (de) * 1998-03-19 2001-01-31 Jbl Incorporated Kurzschlussringe für lautsprecherantrieb mit doppelspulen und doppelspalten
US6289106B1 (en) 1997-08-08 2001-09-11 Hong Long Industrial Co., Ltd. Cap and center pole apparatus and method of coupling
US20030190052A1 (en) * 1998-03-19 2003-10-09 Jbl Incorporated Shorting rings in dual-coil dual-gap loudspeaker drivers
US6774510B1 (en) 2000-10-25 2004-08-10 Harman International Industries, Inc. Electromagnetic motor with flux stabilization ring, saturation tips, and radiator
US20100246880A1 (en) * 2009-03-30 2010-09-30 Oxford J Craig Method and apparatus for enhanced stimulation of the limbic auditory response
EP2833648A3 (de) * 2013-08-01 2015-03-18 Harman International Industries, Inc. Elektrodynamischer Lautsprecher mit leitenden Elementen
GB2527533A (en) * 2014-06-24 2015-12-30 Amina Technologies Ltd Moving coil drive unit and audio drivers incorporating the same
CN107948802A (zh) * 2017-12-25 2018-04-20 厦门东声电子有限公司 一种受话器

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5511278Y2 (de) * 1974-06-07 1980-03-11
JPS5127127U (de) * 1974-08-19 1976-02-27
JPS5152236U (de) * 1974-10-18 1976-04-21
DE3046551A1 (de) * 1980-12-10 1982-07-22 Isophon-Werke Gmbh, 1000 Berlin "dynamischer lautsprecher"
JP5449002B2 (ja) * 2010-04-21 2014-03-19 株式会社オーディオテクニカ 音響用動電型変換器

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1976874A (en) * 1932-11-09 1934-10-16 Brzeski Henryk Loud speaker
US2320402A (en) * 1940-09-30 1943-06-01 Rca Corp Loud-speaker
US3632904A (en) * 1970-03-24 1972-01-04 Paul Mauz Moving coil loudspeaker with eddy current suppression
US3665352A (en) * 1970-05-12 1972-05-23 Deutsche Edelstahlwerke Ag Permanent magnet system for a loudspeaker
US3716677A (en) * 1970-06-05 1973-02-13 Matsushita Electric Ind Co Ltd Multi-channel magnetic head
US3783311A (en) * 1970-12-19 1974-01-01 Coral Audio Corp Magnetic device for use in acoustic apparatus

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE916953C (de) * 1952-05-27 1954-08-23 Helmut Jedlicka Ringspaltmagnet fuer elektrodynamische Lautsprecher
US3440364A (en) * 1965-12-21 1969-04-22 Gen Electric Speaker magnet having curved preferred direction of magnetization
DE1928038A1 (de) * 1969-06-02 1970-12-10 Otto Mayer Selbsttaetig verriegelbares Gelenk

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1976874A (en) * 1932-11-09 1934-10-16 Brzeski Henryk Loud speaker
US2320402A (en) * 1940-09-30 1943-06-01 Rca Corp Loud-speaker
US3632904A (en) * 1970-03-24 1972-01-04 Paul Mauz Moving coil loudspeaker with eddy current suppression
US3665352A (en) * 1970-05-12 1972-05-23 Deutsche Edelstahlwerke Ag Permanent magnet system for a loudspeaker
US3716677A (en) * 1970-06-05 1973-02-13 Matsushita Electric Ind Co Ltd Multi-channel magnetic head
US3783311A (en) * 1970-12-19 1974-01-01 Coral Audio Corp Magnetic device for use in acoustic apparatus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Brailsford, Magnetic Materials, 1960, Methuen & Co., Chaps. 4 & 5. *

Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3922501A (en) * 1971-12-17 1975-11-25 Pioneer Electronic Corp Moving voice coil electro-acoustic converter with laminated magnetically anisotropic poles
US4259550A (en) * 1978-04-15 1981-03-31 Yoshiro Nakamatsu Acoustic device with floating vibrating means
EP0029266A1 (de) * 1979-11-20 1981-05-27 Koninklijke Philips Electronics N.V. Magnetsystem für einen elektroakustischen Wandler
US4378471A (en) * 1981-02-18 1983-03-29 Ibuki Kogyo Co., Ltd. Horn speaker with linear grooves in a front surface of a pole piece of a yoke
US5321762A (en) * 1991-08-05 1994-06-14 Aura Systems, Inc. Voice coil actuator
EP0616751A1 (de) * 1991-08-05 1994-09-28 Aura Systems, Inc. Schwingspulenantrieb
EP0616751A4 (de) * 1991-08-05 1995-05-17 Aura Systems Inc Schwingspulenantrieb.
US5381483A (en) * 1993-04-05 1995-01-10 Commonwealth Of Puerto Rico Minimal inductance electrodynamic transducer
US6289106B1 (en) 1997-08-08 2001-09-11 Hong Long Industrial Co., Ltd. Cap and center pole apparatus and method of coupling
US6473515B2 (en) 1997-08-08 2002-10-29 Ching Tong Wong Cap and center pole apparatus and method of coupling
US6768806B1 (en) * 1998-03-19 2004-07-27 Harman International Industries, Incorporated Shorting rings in dual-coil dual-gap loudspeaker drivers
US6847726B2 (en) * 1998-03-19 2005-01-25 Harman International Industries, Incorporated Shorting rings in dual-coil dual-gap loudspeaker drivers
EP1072168A1 (de) * 1998-03-19 2001-01-31 Jbl Incorporated Kurzschlussringe für lautsprecherantrieb mit doppelspulen und doppelspalten
US20030190052A1 (en) * 1998-03-19 2003-10-09 Jbl Incorporated Shorting rings in dual-coil dual-gap loudspeaker drivers
EP1072168A4 (de) * 1998-03-19 2006-02-08 Jbl Inc Kurzschlussringe für lautsprecherantrieb mit doppelspulen und doppelspalten
WO2001006523A2 (en) * 1999-07-20 2001-01-25 New Transducers Limited Magnet assembly
WO2001006523A3 (en) * 1999-07-20 2001-07-19 New Transducers Ltd Magnet assembly
US7057314B2 (en) 2000-10-25 2006-06-06 Harman International Industries, Inc. Electromagnetic motor system capable of removing heat away from its magnetic gap
US20050179326A1 (en) * 2000-10-25 2005-08-18 Harman International Industries Incorporated Electromagnetic motor with flux stabilization ring, saturation tips, and radiator
US20040239193A1 (en) * 2000-10-25 2004-12-02 Jerry Moro Electromagnetic motor with flux stabilization ring, saturation tips, and radiator
US7012345B2 (en) 2000-10-25 2006-03-14 Harman International Industries, Inc. Electromagnetic motor with flux stabilization ring, saturation tips, and radiator
US6774510B1 (en) 2000-10-25 2004-08-10 Harman International Industries, Inc. Electromagnetic motor with flux stabilization ring, saturation tips, and radiator
US9392357B2 (en) * 2009-03-30 2016-07-12 J. Craig Oxford Method and apparatus for enhanced stimulation of the limbic auditory response
US20110245585A1 (en) * 2009-03-30 2011-10-06 Oxford J Craig Method and apparatus for enhanced stimulation of the limbic auditory response
US20100246880A1 (en) * 2009-03-30 2010-09-30 Oxford J Craig Method and apparatus for enhanced stimulation of the limbic auditory response
EP2833648A3 (de) * 2013-08-01 2015-03-18 Harman International Industries, Inc. Elektrodynamischer Lautsprecher mit leitenden Elementen
US9100738B2 (en) 2013-08-01 2015-08-04 Harman International Industries, Inc. Electrodynamic loudspeaker with conducting elements
GB2527533A (en) * 2014-06-24 2015-12-30 Amina Technologies Ltd Moving coil drive unit and audio drivers incorporating the same
GB2527533B (en) * 2014-06-24 2016-07-13 Amina Tech Ltd Moving coil drive unit and audio drivers incorporating the same
CN107948802A (zh) * 2017-12-25 2018-04-20 厦门东声电子有限公司 一种受话器
CN107948802B (zh) * 2017-12-25 2024-04-23 厦门东声电子有限公司 一种受话器

Also Published As

Publication number Publication date
DE2261501A1 (de) 1973-06-20
DE2261501C3 (de) 1983-04-21
JPS4868219A (de) 1973-09-18
DE2261501B2 (de) 1979-06-21
JPS5235294B2 (de) 1977-09-08

Similar Documents

Publication Publication Date Title
US3830986A (en) Magnetic circuit for an electro-acoustic converter
US3867587A (en) Magnetic circuit for an electro-acoustic converter
US3922501A (en) Moving voice coil electro-acoustic converter with laminated magnetically anisotropic poles
US4868882A (en) Loudspeaker
US7477757B2 (en) Dual-gap transducer with radially-charged magnet
CA1128194A (en) Electroacoustic transducer with magnetic flux directed slantly across a diaphragm
GB2085694A (en) Balanced armature transducers
US3783311A (en) Magnetic device for use in acoustic apparatus
US3766334A (en) Double voice coil loudspeaker
US3881074A (en) Electro-acoustic transducer
US3665352A (en) Permanent magnet system for a loudspeaker
US4295011A (en) Linear excursion-constant inductance loudspeaker
US5381483A (en) Minimal inductance electrodynamic transducer
US3549830A (en) Magnet configuration for a loudspeaker
JP2917578B2 (ja) スピーカ
US2621261A (en) Electroacoustic converter
US1644789A (en) Electromagnetic device
JPH08331691A (ja) 動電型スピーカ
US1630380A (en) Loud-speaker unit
US1420989A (en) Transformer
US2494918A (en) Inductively energized electro-dynamic loud-speaker
US4461933A (en) Electrical/mechanical transducers
US1643169A (en) Telephone receiver
US11290823B2 (en) Double voice coil loudspeaker transducer unit
JP3961960B2 (ja) スピーカ