US2161489A - Vibratory system - Google Patents

Vibratory system Download PDF

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Publication number
US2161489A
US2161489A US167708A US16770837A US2161489A US 2161489 A US2161489 A US 2161489A US 167708 A US167708 A US 167708A US 16770837 A US16770837 A US 16770837A US 2161489 A US2161489 A US 2161489A
Authority
US
United States
Prior art keywords
coil
feedback
stylus
recorder
pole
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
US167708A
Other languages
English (en)
Inventor
Vieth Leonard
Charles F Wiebusch
George R Yenzer
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.)
AT&T Corp
Original Assignee
Bell Telephone Laboratories Inc
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
Priority to NL61306D priority Critical patent/NL61306C/xx
Application filed by Bell Telephone Laboratories Inc filed Critical Bell Telephone Laboratories Inc
Priority to US167708A priority patent/US2161489A/en
Priority to FR844068D priority patent/FR844068A/fr
Priority to GB28295/38A priority patent/GB518442A/en
Priority to DEW718D priority patent/DE868076C/de
Application granted granted Critical
Publication of US2161489A publication Critical patent/US2161489A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01M—CATCHING, TRAPPING OR SCARING OF ANIMALS; APPARATUS FOR THE DESTRUCTION OF NOXIOUS ANIMALS OR NOXIOUS PLANTS
    • A01M23/00—Traps for animals
    • A01M23/02—Collecting-traps
    • A01M23/04—Collecting-traps with tipping platforms
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/34—Negative-feedback-circuit arrangements with or without positive feedback
    • H03F1/36—Negative-feedback-circuit arrangements with or without positive feedback in discharge-tube amplifiers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H04R3/002—Damping circuit arrangements for transducers, e.g. motional feedback circuits
    • 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
    • H04R9/12—Gramophone pick-ups using a stylus; Recorders using a stylus
    • 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
    • H04R9/12—Gramophone pick-ups using a stylus; Recorders using a stylus
    • H04R9/16—Gramophone pick-ups using a stylus; Recorders using a stylus signals recorded or played back by vibration of a stylus in two orthogonal directions simultaneously

Definitions

  • This invention relates to electrically-driven vibratory systems, particularly phonograph-recording systems.
  • the object of this invention is a stable, electromechanical vibrating system of the negative feedggllback type which is capable of substantially distortionless response over the high quality range of frequencies of speech and music.
  • the vibratory system in order to simplify the problem of maintaining proper phase Soirrelations in the feedback circuit, is designed to have only a single resonant peak over the operating range and secondary effects due to resonances of air chambers adjacent Ato the moving system are avoided by providing 35ipaths for the flow of air through the system while it is vibrating. Stable operation is obtained in a compact structure by shielding the feedback element from the main driving element and when necessary any remaining inductive effect of the driving element on the'output of the feedback element may be balancedrout as explained below.
  • the moving system comprises a large 45 ⁇ 2driving coil, a smaller feedback coil and a stylus mounted on the central pole-piece near the feedback coil and connected with it in opposing relationship inthe feedback circuit. Due to the compactness of the structure and the necessity'of using small air-gaps to obtain high efliciency, the moving system has adjacent to it a number of small air chambers. The stiffness of the air entrapped in these chambers would ordinarily be such as to resonate with the mass of the moving system of the recorder or withkthe mass of the air itself to produce secondary resonance effects which would cause singing or irregularities in the response. To prevent these undesirable effects the air stiffness of these chambers is reduced according to the invention by providing a large number of 'small perforations in the diaphragm and driving cone.
  • Fig. 1 is a phonograph recorder, according to the invention.
  • Fig. 2 is an enlarged sectional view showing the vibratory system'of the recorder
  • Fig. V3 is a schematic of a recording system including the recorder of this invention.
  • Figs. 4 to 7 show other vibratory systems which may be used in recorders of this type.
  • the magnet II has a central pole-piece I2 and an outer pole-piece I3 defining an annular gap I4 for the mainsignal driving coil I5 and a second outer pole-piece I 6 which', with the extension piece I1 on the central pole-piece, defines a gap I8 for the feedback coil I9.
  • the stiff cone member on which the coils are mounted is fitted at its apex with a holder 2
  • the feedback coil I9 is shielded from the field set up by the driving coil I5 by a copper ring 26 between the pole-pieces and a second copper ring 10 21 surrounding the pole-piece extension I1.
  • These rings and pole-pieces define adjacent the diaphragm 24 and the cone 26 a number of small air chambers which would ordinarily introduce resonance effects due to the Vstiffness of the con- These resonancesV are avoided in this recorder by providing the diaphragmY and the cone with a larger number of small perforations 28 which allow the air to flow through the vibrating system and thereby reduce the air stiffness to a value which is not objectionable.
  • the rings 26 and 21 constitute between the driving ;'and feedback coils a substantially continuous copper shield which is very effective at the higher frequencies where shielding is most necessary. If the shielding effect so obtained, however, is notV complete enough, particularly at lower fre- 301quencies, it may be ldesirable to provide a third coil 29 in a recess in the ring 21 and adjacent the feedback coil so as to have substantially the same mutual inductance as the latter with the driving coil. This coil when used is then connected in the feedback circuit in serially opposing relation to the feedback coil.
  • Fig. 3 which shows an amplifying system which has been found to work satisfactorily with this recorder
  • the currents representing the signal to be recorded are derived from any suitable source such as a microphone 30 and are amplified to some intermediate level by an amplifier 3l in the usual manner.
  • the output of this amplifier passes through the tube 32 Where it is combined with the feedback energy from the recorder as more fully explained below,
  • the vibrating system of the recorder drives the stylus to cut a record in accord- 70.; ance with the impressed signal currents and also drives the feedback coil I9 to generate a voltage which is proportional to the stylus velocity.
  • the amplifying system may be provided with an internal negative feedback path extending from the plate 43 ofthe tube 35 to the screen grid 44 of the tube 33.
  • This circuit may comprise a resistor 45 shunted by a condenser 46 and the second condenser 41 in series therewith in the connection to the screen grid 44 and a condenser 48 shunting an adjustable portion of the resistor 49 which supplies potential tothe grid 44 from the rectifier 56 in the usual manner.
  • the capacity of the condenser 48 is such as to decrease the feedback at high frequencies and keep the response of the recorder at the proper level in the region where it would otherwise tend to droop and the small condenser 46 controls the phase shift to prevent the feedback from becoming positive and producing instability at super-audible frequencies.
  • This internal feedback loop also reduces harmonic distortion, improves the impedance matching between the tube 35 and the recorder and also reduces the objectionable phase shift of the output transformer 5I.
  • the member 20 carrying the coils I5 and I9 and the stylus 22 of the recorder has been shown and described as a stiff cone, this singly resonant member may take other forms, some of which are shown in Figs. 4 to 7.
  • the member 60 comprises an upper cylindrical portion 6I for the coil I5 and a lower cylindrical portion 62 for the feedback coil 63 joined together by the conical portion 64.
  • a single cylindrical portion 65 mounts both the signal coil I5 and the feedback coil 66 which,
  • coil 63 of Fig. 4 is also of the cylindrical type. These coils are not only easier to make and mount than the coil I9 of Fig. 1, but they also permit the use of a short vertical air-gap which gives a higher fiux density at the coil and therefore a higher feedback voltage.
  • the coil support 61 of Figs. 6 and '7 has an upper cylindrical portion 68 for the driving coil I5 and tapers to a thin rectangular end portion 'I0 at the stylus 22. Within this fiattened portion 'I0 at right angles to the plane of the coil I5 a rectangular coil 'II is disposed with one side in the gap defined by the pole-pieces I6. Since the two coils of this structure have substantially no mutual inductance, the shielding problem is greatly simplified and in many cases no shielding between the coils will be necessary,
  • a magnetic circuit having a central pole-piece and two spaced annular pole-pieces forming air-gaps, a vibratory system comprising driving and driven coils disposed in the gaps, a stylus, a rigid member connecting the coils to the stylus and a resilient support for the member, and stationary means between the pole-pieces for shielding the driven -coil from the eld of the driving coil.
  • a recording device comprising a. magnet system having two annular gaps and a vibratory system including a driving coil in one o-f the gaps carrying currents representing sounds to be recorded, a driven coil in the other gap for generating currents to control the motion of the vibratory system, a stylus and means for connecting the coils to the stylus, and a third, stationary coil connected in opposed relationship to the driven coil with respect to currents. induced therein by the field of the driving coil.
  • a magnet system having a central pole-piece and two spaced annular pole-pieces dening gaps anda vibratory system comprising a stylus, a driving coil therefor in one of the gaps, a driven coil in the other gap for controlling the motion of the stylus, a rigid member connecting the coils to the stylus and a resilient support for the member, said member and support dening with the pole-pieces a plurality of small substantially closed air chambers, and perorations in the member and support for reducing the stiffness of the air in the chambers whereby the system has only a single resonant frequency within the operating frequency range of the device.
  • a vibration translating device in a vibration translating device a magnetic circuit having a central pole-piece and two spaced annular pole-pieces forming air-gaps, a vibratory system comprising driving and driven coils disposed in the gaps, a driven member and rigid means interconnecting the member and the coils, resilient supporting means for the system and a substantially continuous member of high conductivity extending between the annular polepieces and shielding the driven coil from the field of the driving coil.
  • a magnetic circuit comprising a magnet having a central pole-piece and an annular pole-piece forming a relatively large upper gap, and a pole-piece extension and a second annular pole-piece forming a smaller lower gap, a vibrating system comprising a driven member, a driving coil in the upper gap, a driven coil in the lower ⁇ gap, and rigid means connecting the driven member and driven coil to the driving coil, a resilient support for the vibratory system, shielding means for the driven coil, and a circuit including an amplifier connecting the driven coil to the driving coil.
  • a magnetic circuit dening two spaced air-gaps a vibrating system comprising a driving coil, a stylus, a feedback coil and means connected to the stylus for mounting the coils for vibration in the gaps and having such mass and stii'lness as to have a single resonant frequency within the operating range, and stationary shielding on both sides of the coil mounting means forming a substantially continuous shield between the coils.
  • a magnetic circuit deiining two spaced air-gaps, a driving coil in one of the gaps, a resilient support therefor, a stylus, a stiff conical member connecting the coil to the stylus and a feedback coil mounted on the conical member and disposed in the other gap.
  • a vibratory system for feedback recorders comprising a driving coil, a resilient support therefor, a stylus, a rigid member connecting the coil to the stylus and a feed-back coil supported by the member and disposed in a plane at rightangles to the plane of the driving coil.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Signal Processing (AREA)
  • Acoustics & Sound (AREA)
  • Pest Control & Pesticides (AREA)
  • Insects & Arthropods (AREA)
  • Power Engineering (AREA)
  • Environmental Sciences (AREA)
  • Zoology (AREA)
  • Wood Science & Technology (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)
  • Apparatuses For Generation Of Mechanical Vibrations (AREA)
  • Amplifiers (AREA)
  • Reciprocating, Oscillating Or Vibrating Motors (AREA)
US167708A 1937-10-07 1937-10-07 Vibratory system Expired - Lifetime US2161489A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
NL61306D NL61306C (de) 1937-10-07
US167708A US2161489A (en) 1937-10-07 1937-10-07 Vibratory system
FR844068D FR844068A (fr) 1937-10-07 1938-09-28 Dispositif pour la conversion de vibrations électro-mécaniques
GB28295/38A GB518442A (en) 1937-10-07 1938-09-29 Electro-mechanical vibration translating systems
DEW718D DE868076C (de) 1937-10-07 1938-10-07 Einrichtung zur elektro-mechanischen Schwingungsuebertragung

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US167708A US2161489A (en) 1937-10-07 1937-10-07 Vibratory system

Publications (1)

Publication Number Publication Date
US2161489A true US2161489A (en) 1939-06-06

Family

ID=22608481

Family Applications (1)

Application Number Title Priority Date Filing Date
US167708A Expired - Lifetime US2161489A (en) 1937-10-07 1937-10-07 Vibratory system

Country Status (5)

Country Link
US (1) US2161489A (de)
DE (1) DE868076C (de)
FR (1) FR844068A (de)
GB (1) GB518442A (de)
NL (1) NL61306C (de)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2475200A (en) * 1945-06-28 1949-07-05 Rca Corp Signal recording apparatus
US2508783A (en) * 1945-02-16 1950-05-23 Lionel B Cornwell Electrical sound translating device
US2509968A (en) * 1943-07-09 1950-05-30 Hartford Nat Bank & Trust Co Electrodynamic pickup
US2522567A (en) * 1946-06-21 1950-09-19 Emory G Cook Amplifier feed-back system for magnetic motors
US2531242A (en) * 1947-09-05 1950-11-21 Bell Telephone Labor Inc Electrodynamic phonograph pickup
US2617894A (en) * 1947-01-11 1952-11-11 Arentzen Holger Christian Electrodynamic recording device
US2622156A (en) * 1949-01-27 1952-12-16 Donald J Baker Pickup head with removable armature and stylus assembly
US2858375A (en) * 1955-10-11 1958-10-28 Rca Corp Wide range dynamic phonograph pickup
US2962561A (en) * 1956-03-20 1960-11-29 Teldec Telefunken Decca Method and apparatus for dual sound track recording
US3014992A (en) * 1956-03-16 1961-12-26 Telefunken Gmbh Dual sound track transducer head
US3020361A (en) * 1956-01-23 1962-02-06 Jerry B Minter Electromagnetic engraving apparatus
US3236955A (en) * 1960-02-02 1966-02-22 Telefunken Ag Stereophonic electrodynamic transducer

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE357316C (de) * 1922-08-22 Horace Owen Merriman Apparat zum Aufzeichnen von Toenen
GB160223A (en) * 1919-11-18 1921-03-18 Adrian Francis Sykes Improvements in telephonic and like apparatus
US1535538A (en) * 1923-01-03 1925-04-28 Western Electric Co Vibratory system
US1645582A (en) * 1924-11-20 1927-10-18 Studebaker Corp Top construction
GB350954A (en) * 1930-03-10 1931-06-10 Alan Dower Blumlein Improvements in electro-mechanical sound recording devices more especially of the moving coil type

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2509968A (en) * 1943-07-09 1950-05-30 Hartford Nat Bank & Trust Co Electrodynamic pickup
US2508783A (en) * 1945-02-16 1950-05-23 Lionel B Cornwell Electrical sound translating device
US2475200A (en) * 1945-06-28 1949-07-05 Rca Corp Signal recording apparatus
US2522567A (en) * 1946-06-21 1950-09-19 Emory G Cook Amplifier feed-back system for magnetic motors
US2617894A (en) * 1947-01-11 1952-11-11 Arentzen Holger Christian Electrodynamic recording device
US2531242A (en) * 1947-09-05 1950-11-21 Bell Telephone Labor Inc Electrodynamic phonograph pickup
US2622156A (en) * 1949-01-27 1952-12-16 Donald J Baker Pickup head with removable armature and stylus assembly
US2858375A (en) * 1955-10-11 1958-10-28 Rca Corp Wide range dynamic phonograph pickup
US3020361A (en) * 1956-01-23 1962-02-06 Jerry B Minter Electromagnetic engraving apparatus
US3014992A (en) * 1956-03-16 1961-12-26 Telefunken Gmbh Dual sound track transducer head
US2962561A (en) * 1956-03-20 1960-11-29 Teldec Telefunken Decca Method and apparatus for dual sound track recording
US3236955A (en) * 1960-02-02 1966-02-22 Telefunken Ag Stereophonic electrodynamic transducer

Also Published As

Publication number Publication date
FR844068A (fr) 1939-07-18
GB518442A (en) 1940-02-27
DE868076C (de) 1953-02-23
NL61306C (de)

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