US3911486A - Commutating rotary transformer - Google Patents

Commutating rotary transformer Download PDF

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Publication number
US3911486A
US3911486A US454257A US45425774A US3911486A US 3911486 A US3911486 A US 3911486A US 454257 A US454257 A US 454257A US 45425774 A US45425774 A US 45425774A US 3911486 A US3911486 A US 3911486A
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United States
Prior art keywords
section
primary
windings
winding
disposed
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
US454257A
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English (en)
Inventor
Earl Roger Hibbard
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.)
Omron Business Systems Inc
Original Assignee
American Videonetics 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 American Videonetics Corp filed Critical American Videonetics Corp
Priority to US454257A priority Critical patent/US3911486A/en
Priority to GB1119875A priority patent/GB1457383A/en
Priority to DE2512388A priority patent/DE2512388C2/de
Priority to FR7509152A priority patent/FR2266272B1/fr
Priority to CA222,865A priority patent/CA1032621A/en
Priority to NL7503483A priority patent/NL7503483A/xx
Priority to JP50036513A priority patent/JPS50134413A/ja
Application granted granted Critical
Publication of US3911486A publication Critical patent/US3911486A/en
Assigned to OMRON BUSINESS SYSTEMS, INC. A CORP. OF DE reassignment OMRON BUSINESS SYSTEMS, INC. A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: AMERICAN VIDEONETICS CORPORATON A CA CORP.
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • H01F38/00—Adaptations of transformers or inductances for specific applications or functions
    • H01F38/18—Rotary transformers
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
    • G11B15/02—Control of operating function, e.g. switching from recording to reproducing
    • G11B15/12—Masking of heads; circuits for Selecting or switching of heads between operative and inoperative functions or between different operative functions or for selection between operative heads; Masking of beams, e.g. of light beams
    • G11B15/14—Masking or switching periodically, e.g. of rotating heads
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
    • G11B5/52—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with simultaneous movement of head and record carrier, e.g. rotation of head
    • G11B5/53—Disposition or mounting of heads on rotating support

Definitions

  • ABSTRACT Commutating rotary transformer having a primary section which rotates with the head assembly and a stationary secondary section which is mounted adjacent to the primary section.
  • the primary section has a plurality of arcuately disposed windings Wound on radially extending magnetic core segments, the number of windings and core segments corresponding to the number of heads.
  • the secondary section has an arcuately disposed winding wound on a radially extending magnetic core segment which is disposed to be aligned successively with different ones of the primary core segments as the primary section rotates, whereby the signals from different ones of the rotating transducer heads are successively coupled to the stationary secondary winding.
  • a transverse scanning recorder of the prior art commonly known as a quadraplex recorder, has four transducer heads spaced in quadrature about an axis extending in a direction generally parallel to the direction of tape travel. As the tape moves past the rotating head assembly, it is scanned successively by the four heads along paths lying generally perpendicular to the direction of tape travel.
  • each transformer has a primary winding and a secondary winding, and the windings are disposed side-by-side along the axis of rotation, with the primary windings constrained for rotation with the head assembly and the secondary windings stationary.
  • This switcher is a complicated network which delivers the signals from different ones of the heads in a predetermined order, and it is generally necessary to amplify the signals from the transformer secondaries before they are applied to the switcher. This requires a separate preamplifier for each of the channels.
  • the transformer includes a primary section which rotates with the head assembly and a stationary secondary section which is mounted adjacent to the primary section.
  • the primary section has a plurality of arcuately disposed windings wound on radially extending magnetic core segments, the number of windings and core segments corresponding to the number of heads.
  • the secondary section has an arcuately disposed winding wound on a radially extending magnetic core segment which is disposed to be aligned successively with different ones of the primary core segments as the primary section rotates, whereby the signals from different ones of the rotating transducer heads are successively coupled to the stationary secondary winding.
  • the primary windings are arranged in two groups disposed along concentric circular paths of different radii
  • the secondary includes two radially extending magnetic core segments with an arcuately disposed winding on each, with each of the secondary windings being disposed to be coupled with the windings in only one of the two primary groups.
  • the secondary windings are arranged to provide a slight overlap at the beginning and end of each scan, and switching be tween the secondary windings is provided by a simple two channel switcher.
  • Another object of the invention is to provide a commutating rotary transformer of the above character which is particularly suitable for use in a transverse scan tape recorder.
  • FIG. 1 is an elevational view of the primary section of a commutating rotary transformer according to the invention.
  • FIG. 2 is an elevational view of the secondary section of a commutating rotary transformer according to the invention.
  • FIG. 3 is a sectional view of the assembled transformer, taken along lines 33 in FIGS. 1 and 2.
  • FIG. 4 is a block diagram illustrating the use of the transformer of FIGS. l3 in a transverse scan tape recorder.
  • FIGS. 1 and 4 the invention is illustrated in connection with the rotating head assembly of a transverse scan recorder having eight circumferentially spaced heads designated Hl-HS.
  • the heads are positioned for scanning a magnetic tape T in a direction generally perpendicular to the direction normal to the plane of the page, and in the vicinity of the head assembly the tape is bowed transversely by a suitable guide, not shown.
  • the spacing between adjacent heads is made less than the width of the tape to provide a few degrees of overlap at the end of one scan and the beginning of the next.
  • the commutating rotary transformer comprises a primary section 10 and a secondary section II.
  • the primary section includes a cup-shaped base 16, and it is affixed to the head assembly and constrained for rotation therewith by a screw 17.
  • a plurality of radially extending magnetic core segments 21-28 are mounted on base 16 and arranged in an inner group consisting of the odd numbered segments.
  • the core segments are generally sector shaped, and the segments in the inner group are spaced in quadrature about a central core section 29.
  • the outer segments are interposed between the inner segments, and they are separated from the inner segments and the central core section by air gaps 31 and 32.
  • Base 16 is preferably fabricated of a nonmagnetic material such as aluminum, and the core segments are fabricated of a ferrite material such as Ferroxcube 4C4. Alternatively, if desired, aluminum or another non-magnetic material can be utilized in place of air gaps 31 and 32 between the inner and outer core segments.
  • Primary windings P1P8 are wound on core segments 21-28 and disposed in arcuately extending slots in the segments.
  • each primary winding consists of seven turns of No. 47 copper wire.
  • the even numbered windings i.e. the windings on the inner group of core segments, are disposed along a circular path having a radius less than the inner radius of the outer core segments.
  • the odd numbered windings are disposed along a circular path which has a radius greater than the outer radius of the inner core segments.
  • connections to the primary windings are made by leads passing through openings 36 in base 16 to a printed circuit board 37 which is mounted in a recessed area at the rear of the base.
  • Connector pins 38 on the circuit board mate with sockets on the head assembly, and connections between the winding leads and the connector pins are made by conductive foil on the circuit board.
  • the odd numbered heads are connected to the windings adjacent to them, and the even numbered heads are connected to the diametrically opposed windings.
  • head H1 is connected to the adjacent winding Pl
  • head H2 is connected to the opposed winding P2, and so on.
  • the secondary section 11 of the transformer includes a cup-shaped base 41 which is preferably fabricated of a nonmagnetic material such as aluminum.
  • a hollow threaded stud 42 extends axially from the rear of the base to provide means for mounting the secondary section.
  • Magnetic core sections 51 and 52 are mounted on the front of base 41. Segments 51 and 52 are generally sector-shaped, and they are fabricated of a high frequency ferrite material such as Ferroxcube 4C4.
  • Secondary windings S1 and S2 are wound on segments 51 and 52 and disposed in arcuately extending slots in the segments.
  • Winding S1 is disposed along a circular path having a radius corresponding to the radius of the outer group of primary windings
  • winding S2 is disposed along a circular path having a radius corresponding to the inner group of primary windings.
  • each of the secondary windings have seven turns of No. 47 copper wire.
  • Leads from the windings pass through openings 54 in base 41 to a printed circuit board 56 which is mounted in the rear of the base. Conductive foil leads on the circuit board provide connections between the winding leads and conductors leading to the circuitry with which the transformer is used.
  • the primary and secondary sections are disposed coaxially of the head assembly, with the axial faces of the core segments confronting each other. These faces are preferably lapped so that segments of the two sections can be in close proximity to minimize losses across the air gap between them.
  • Secondary winding S1 is aligned with the odd numbered primary windings
  • secondary winding S2 is aligned with the even numbered primary windings.
  • the secondary core segments and windings are wider than the primary core segments and windings, and in the preferred embodi ment each of the primary windings has an arc length on the order of 45 and each of the secondary windings has an arc length on the order of 90.
  • втори ⁇ еска ⁇ ⁇ тор ⁇ ⁇ иров S1 and S2 are connected to the inputs of preamplifiers 61 and 62, respectively.
  • the outputs of the preamplifiers are connected to a two channel switcher 63 of known design.
  • the output of the switcher is connected to the playback circuitry 64 of the tape recorder.
  • Switcher 63 operates in synchronization with the head assembly, alternately passing the signals from the two secondary windings to the playback circuitry. In a video recorder where each scan ofa head across the tape corresponds to a number of horizontal lines of the picture, for example 10 to 20 lines, switching occurs just before the horizontal sync pulse during the front porch interval for the first line of each scan.
  • the primary section is mounted coaxially of the rotating head assembly of a transverse scanning recorder and constrained for rotation therewith.
  • the secondary section is mounted in a fixed position coaxially of the primary section with the core segments of the primary section in close axial proximity to the core segments of the secondary section. As the head assembly and primary section rotate, the secondary core segments are aligned with successive ones of the primary segments to provide coupling with successive ones of the primary windings.
  • primary core segments 21 and 24 are aligned with secondary core segment 51, and primary segments 25 and 28 are aligned with secondary segment 52.
  • Windings Pland S1 are coupled by core segments 21 and 51, and windings P8 and S2 are coupled by segments 28 and 52. None of the other primary windings are coupled to the secondary windings.
  • core segments 24 and 51 are aligned, there is no coupling between primary winding P4 and secondary winding S1 because these windings lie on different radii.
  • there is no coupling between windings P5 and S2 because they also lie on different radii.
  • head H1 scans across tape T, and the output signal from this head is delivered to the playback circuitry by windings P1 and S1 and switcher 63.
  • head H2 begins to scan the tape. While head H2 scans the tape, primary core segment 22 is aligned with secondary segment 52, and primary winding P2, which is connected to head H2, is coupled to secondary winding S2.
  • the switcher delivers the signal from secondary winding S2 to the playback circuitry.
  • the process continues, and the output signals from the different heads are delivered to the playback circuitry in the desired sequence.
  • each head begins its scan slightly before the proceeding head has completed its scan, there is a slight overlap in the signals delivered to the secondary windings for successive portions of the picture. This overlap is eliminated by the switcher and is not visible in the picture. The switching occurs during the retrace interval between lines, and there is no loss of picture information during it.
  • the record signal is fed.
  • the record signal is coupled to the odd numbered and even numbered heads as they scan the tape in sequence. No external signal switching is performed during the record process, hence each head records a path on the tape which extends more than 45 in arc length.
  • the redundant recording at the beginning and end of each scan provides the overlap for the playback process.
  • a commutating rotary transformer for successively coupling signals to or from a plurality of rotating transducer heads in a tape recorder, said transformer comprising: a primary section constrained for rotation about an axis with the transducer heads, said primary section having a plurality of radially extending magnetic core segments and an arcuately disposed primary winding on each of the core segments, each primary winding being connected to a different one of the transducer heads, and a stationary secondary section comprising a radially extending magnetic core segment and an arcuately disposed winding on the core segment, the secondary section being disposed coaxially of the primary section and spaced axially therefrom with the secondary core segment in close proximity to the primary core segments and positioned to be aligned successively with different ones of the primary segments as the primary section rotates, whereby different ones of the rotating transducer heads are successively coupled to the stationary secondary winding.
  • a commutating rotary transformer for coupling electrical signals with a plurality of circuits carried by a rotative member, said transformer comprising: a first section disposed coaxially of the rotative member and constrained for rotation therewith, said first section having a plurality of radially extending magnetic core segments and a plurality of spaced apart arcuately disposed windings wound on the core segments, said windings being connected to the circuits carried by the rotative member, and a second section comprising a radially extending magnetic core segment and an arcuately disposed winding wound on the core segment, said sec ond section being disposed coaxially of the first section and spaced axially therefrom with the core segment of the second section in close proximity to the core segments of the first section, the core segment of the sec ond section being aligned successively with different ones of the core segments of the first section as said first section rotates whereby the winding on the second section is coupled successively to the windings on the first section.
  • the commutating rotary transformer of claim 2 wherein the windings of the first section are disposed along a circular path of predetermined radius centered about the axis of rotation and the winding of the second section is disposed on an arcuate path of the predetermined radius.
  • a commutating rotary transformer for successively coupling signals to or from a plurality of rotating transducer heads in a tape recorder, said transformer comprising: a primary section constrained for rotation about an axis with the transducer heads, said primary section having a plurality of radially extending mag netic core segments and an arcuately disposed primary winding on each of the core segments, each primary winding being connected to a different one of the transducer heads, and a stationary secondary section comprising a radially extending magnetic core segment and an arcuately disposed winding on the core segment, the primary windings being arranged in two groups disposed respectively along circular paths of first and second predetermined radii centered about the axis of rotation and the secondary section having two radially extending magnetic core segments and an arcuately disposed winding on each of said segments, the secondary windings being spaced from the axis of rotation by distances corresponding respectively to the first and second radii, the secondary section being disposed coaxially of the
  • a commutating rotary transformer for coupling electrical signals with a plurality of circuits carried by a rotative member, said transformer comprising: a first section disposed coaxially of the rotative member and constrained for rotation therewith, said first section having a plurality of radially extending magnetic core segments and a plurality of spaced apart arcuately disposed windings wound on the core segments, said windings being connected to the circuits carried by the rotative member, and a second section comprising a radially extending magnetic core segment and an arcuately disposed winding wound on the core segment, the windings of the first section being arranged in two groups disposed respectively along circular paths of first and second predetermined radii centered about the axis of rotation and the second section having two radially extending magnetic core segments and two windings disposed respectively on arcuate paths of said first and second radii, the second section being disposed coaxially of the first section and spaced axially therefrom with the core segment of the second section in

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Recording Or Reproducing By Magnetic Means (AREA)
US454257A 1974-03-25 1974-03-25 Commutating rotary transformer Expired - Lifetime US3911486A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US454257A US3911486A (en) 1974-03-25 1974-03-25 Commutating rotary transformer
GB1119875A GB1457383A (en) 1974-03-25 1975-03-18 Commutating rotary transformer
DE2512388A DE2512388C2 (de) 1974-03-25 1975-03-21 Umlaufender Umschalttransformator
CA222,865A CA1032621A (en) 1974-03-25 1975-03-24 Commutating rotary transformer
FR7509152A FR2266272B1 (fi) 1974-03-25 1975-03-24
NL7503483A NL7503483A (nl) 1974-03-25 1975-03-24 Elektrische transformator met een aantal om een as draaibare wikkelingen, en dienende voor het vormen van elektrische verbindingen met ketens die zijn gemonteerd op een om een as draaibaar draagorgaan.
JP50036513A JPS50134413A (fi) 1974-03-25 1975-03-25

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US454257A US3911486A (en) 1974-03-25 1974-03-25 Commutating rotary transformer

Publications (1)

Publication Number Publication Date
US3911486A true US3911486A (en) 1975-10-07

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Application Number Title Priority Date Filing Date
US454257A Expired - Lifetime US3911486A (en) 1974-03-25 1974-03-25 Commutating rotary transformer

Country Status (7)

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US (1) US3911486A (fi)
JP (1) JPS50134413A (fi)
CA (1) CA1032621A (fi)
DE (1) DE2512388C2 (fi)
FR (1) FR2266272B1 (fi)
GB (1) GB1457383A (fi)
NL (1) NL7503483A (fi)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4040101A (en) * 1974-10-17 1977-08-02 Grundig E.M.V. Elektro-Mechanische Versuchsanstalt Max Grundig System for extending the playing time of video cassettes
US4099210A (en) * 1976-10-04 1978-07-04 Dolby Dale P Rotating transducing head assembly
US4139871A (en) * 1975-11-24 1979-02-13 Nippon Hoso Kyokai Eight-head magnetic video tape recording and reproducing apparatus with rotary transformer
US4827360A (en) * 1987-07-20 1989-05-02 Victor Company Of Japan, Ltd. Rotary transformer with winding to cancel crosstalk
EP0399812A2 (en) * 1989-05-23 1990-11-28 Kabushiki Kaisha Toshiba Magnetic recording and reproduction apparatus
US5017901A (en) * 1989-07-15 1991-05-21 Tanashin Denki Co., Ltd. Controller for a movable member
US5126906A (en) * 1989-04-17 1992-06-30 Hitachi, Ltd. Rotary magnetic head device with rotary transformer having high coupling coefficient
US5363263A (en) * 1991-04-19 1994-11-08 Hitachi Ltd. Coil assembly for rotary magnetic head apparatus
US5434720A (en) * 1989-05-23 1995-07-18 Kabushiki Kaisha Toshiba Magnetic recording and reproduction apparatus with plural heads
EP0717872A1 (en) * 1993-08-30 1996-06-26 Conner Peripherals, Inc. Multi-channel rotating transformer
US20110285491A1 (en) * 2009-01-14 2011-11-24 Rolls-Royce Plc Rotary transformer

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6112572Y2 (fi) * 1979-03-14 1986-04-19
JPS62109304A (ja) * 1985-11-08 1987-05-20 Canon Electronics Inc ロ−タリ−トランス
DE3724349A1 (de) * 1987-07-23 1989-02-02 Thomson Brandt Gmbh Drehtransformator fuer einen recorder

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3361878A (en) * 1964-03-11 1968-01-02 Ampex Signal switching system utilizing magnetic switching for rotating head recorders

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA923207A (en) * 1971-01-04 1973-03-20 R. Gooch Beverley Interchannel shield for multichannel rotary transformer

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3361878A (en) * 1964-03-11 1968-01-02 Ampex Signal switching system utilizing magnetic switching for rotating head recorders

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4040101A (en) * 1974-10-17 1977-08-02 Grundig E.M.V. Elektro-Mechanische Versuchsanstalt Max Grundig System for extending the playing time of video cassettes
US4139871A (en) * 1975-11-24 1979-02-13 Nippon Hoso Kyokai Eight-head magnetic video tape recording and reproducing apparatus with rotary transformer
US4099210A (en) * 1976-10-04 1978-07-04 Dolby Dale P Rotating transducing head assembly
US4827360A (en) * 1987-07-20 1989-05-02 Victor Company Of Japan, Ltd. Rotary transformer with winding to cancel crosstalk
US5126906A (en) * 1989-04-17 1992-06-30 Hitachi, Ltd. Rotary magnetic head device with rotary transformer having high coupling coefficient
EP0399812A3 (en) * 1989-05-23 1992-04-01 Kabushiki Kaisha Toshiba Magnetic recording and reproduction apparatus
EP0399812A2 (en) * 1989-05-23 1990-11-28 Kabushiki Kaisha Toshiba Magnetic recording and reproduction apparatus
US5276565A (en) * 1989-05-23 1994-01-04 Kabushiki Kaisha Toshiba Rotary type magnetic recording and reproduction apparatus
US5434720A (en) * 1989-05-23 1995-07-18 Kabushiki Kaisha Toshiba Magnetic recording and reproduction apparatus with plural heads
US5017901A (en) * 1989-07-15 1991-05-21 Tanashin Denki Co., Ltd. Controller for a movable member
US5363263A (en) * 1991-04-19 1994-11-08 Hitachi Ltd. Coil assembly for rotary magnetic head apparatus
EP0717872A1 (en) * 1993-08-30 1996-06-26 Conner Peripherals, Inc. Multi-channel rotating transformer
EP0717872A4 (fi) * 1993-08-30 1996-07-31
US20110285491A1 (en) * 2009-01-14 2011-11-24 Rolls-Royce Plc Rotary transformer
US8350656B2 (en) * 2009-01-14 2013-01-08 Rolls-Royce Plc Rotary transformer

Also Published As

Publication number Publication date
GB1457383A (en) 1976-12-01
DE2512388A1 (de) 1975-10-02
CA1032621A (en) 1978-06-06
DE2512388C2 (de) 1983-12-01
FR2266272B1 (fi) 1978-11-03
JPS50134413A (fi) 1975-10-24
FR2266272A1 (fi) 1975-10-24
NL7503483A (nl) 1975-09-29

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PA Patent available for licence or sale
AS Assignment

Owner name: OMRON BUSINESS SYSTEMS, INC. 1300 NORTH BASSWOOD R

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:AMERICAN VIDEONETICS CORPORATON A CA CORP.;REEL/FRAME:004306/0720

Effective date: 19840809