US1599418A - Sound-reproducing apparatus - Google Patents

Sound-reproducing apparatus Download PDF

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Publication number
US1599418A
US1599418A US65472A US6547225A US1599418A US 1599418 A US1599418 A US 1599418A US 65472 A US65472 A US 65472A US 6547225 A US6547225 A US 6547225A US 1599418 A US1599418 A US 1599418A
Authority
US
United States
Prior art keywords
transformer
resistance
pick
sound
potentiometer
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
US65472A
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English (en)
Inventor
Edward W Kellogg
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.)
General Electric Co
Original Assignee
General Electric Co
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 BE340865D priority Critical patent/BE340865A/fr
Priority to BE337501D priority patent/BE337501A/xx
Priority to BE338052D priority patent/BE338052A/fr
Application filed by General Electric Co filed Critical General Electric Co
Priority to US65472A priority patent/US1599418A/en
Application granted granted Critical
Publication of US1599418A publication Critical patent/US1599418A/en
Priority to FR32468D priority patent/FR32468E/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R11/00—Transducers of moving-armature or moving-core type
    • H04R11/08—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
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • 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
    • H04R3/04—Circuits for transducers, loudspeakers or microphones for correcting frequency response
    • H04R3/08—Circuits for transducers, loudspeakers or microphones for correcting frequency response of electromagnetic transducers

Definitions

  • My present invention relates to apparatus for the reproduction of sound, and more particularly to systems in which electric currents produced from sound records are amplified by means of thermionic amplifiers and employed for sound reproduction.
  • the prefera le means for accomplishing this is to control the voltage supplied to the input ofthe amplifier. In some cases this may be accomplished by means of a variable.
  • rat1o transformer which may be an' autotransformer, between the pick-up device by which the electric currents are produced and the-input circuit of the amplifier.
  • sistance potentiometer control is preferable to the use-of a variable ratio transformer.
  • the resistance potentiomter can in general be more cheaply constructed than the transformer, and if properly designed it introduces less distortion of the audio fre quency current than does atransformer.
  • Transformers give -rise to distortion because .of distributed capacity in their windings,
  • the ob ect of my invention is to provide a means .for controllin the intensity of they sound produced by sue a system in such a way as to avoid distortion-
  • a more specific ob ect of my invention is to provld'e an apparatus in which all uencies will be re-" 1 produced substanti y their with particularity n the appended claims;
  • the out- 3 put O1IC 111t- 0f the device includes the primary of a-transformer '4.
  • the w1nd1ng ,5' of this transformer is arrang to supply current to the actuating 00116 of a repr0du'cing'device.-
  • This coil may be employed to actuate a diaphragm 7, desired -'type.
  • the currents supphed to t e input circuit of the ampl bomb may be produced byapick-up de- V106 comprising an armature 8, which is' adapted to be, vibra'tedby a stylus 9 operatinglin the groove of an ofdinary phonogrep record.
  • the armature 8 may be.
  • Theflux ispro ijced by a magnet which is not indicated.
  • I include" in the circuitbetween coil 10 and 'the primary of transformer 2 a potentiometer com prising a resistance 11, which is shunted tap 12 the amount of-this resistance which'is included .shunt to the primarypf- .the l transformer .2 may be varied sit-will and thereby the voltage appliedto'the amplifier. and ,theintensi ofthe sound produced by ⁇ the (iliaphragm may be controlled as. deslre I I I havethat in; a "suchjas shownand described, there must be certain relations between the. reactance ofthe mag netic. pickup,t ?the" reactance of the; trans-' former'primary the resistance of-thei o'-- tentiometer, in" order that distortion may be avoided.
  • the-po tentiometer must have a total J which exceeds the maximum reactancej of the pick-up at the frequencies to be reproduced; At the same time the minimungiren transformer circuit.
  • tentiometer is set for per cent of the actance'of the transformer primary winding high frequency components. should exceed the maximum. resistance which coil has a lower "inductanceor the transcanbe introduced into the transformer cirformer a higher inductance than required cuit by the potentiometer.
  • a greater ometer is .set for maximum' intensity, that latitude in the choice of resistance for the is, with the. tap 12 connected to the end of potentiometer and the range of frequency the resistance 11, so that the total resistance which can be covered without appreciable is included in shunt to the transformer. distortion is increased.
  • the potentiometer may have simply constitutes an extra load across the, any value of resistance desired, between pick-up device.
  • the po- 25,000 and 75,000 ohms When, however, the po- 25,000 and 75,000 ohms.
  • any other setting of the former connected in the input'circu-it of said tap 12 will give a'lower resistance in the amplifier and arranged to be supplied with I current from said-pick-up device, and a po-
  • Thetransformer reactance will be a minimum of 100 cycles and will be equal to w This should preferably exceed a quarter of the resistance of the potentiometer, orin.
  • the potentiometer resistance should be less than/ix 18,800, or 75,000 ohms. If this condition is not complied with there will be an unduly large loss of low fre- "qiiencies' in their reproduction. With the value'given, current at 100 cycles would suffer a loss of about 30 per cent as compared with a 1000 cycle current but this loss is not ordinarily suflicient to injure the acoustic reproduction. If the potentiometer resistance is made higher thanthe value given, the low frequencies will be reduced to a much greater extent. On the other hand, a lowering of the resistance makes only a slight reduction in the diiference between.
  • the pick-up coil must be made to have a maximum reactance which will not exceed 75,000 ohms. Since this reactance .will be greatest at the highest fre] quency required, and 4000has been assumed as the upper frequency limit, the inductance of the pick-up coil .must not exceed as the maximum reactancye of said pic -up dycleswithoutfappreciable dis-.- device and the minimum reactance of the primary winding of said transformer being at least bstantially 'as great as the maximum resistance introduced in the circuit of the transformer by the potentiometer.
  • a thermionic amplifier adapted to amplify audio frequency currents, a pick-up device for producing elec-' tric currents from sound records, a trans- If the pick-up former connected in the input circuit of. said amplifier and arranged to be supplied" with current from said pick-up device, a
  • I w 3 The combinationin a sound reproduc- .in apparatus of a thermionic amplifier ad apted to amplify audio frequency currents, a pick-up device adapted to produce electric currents from sound records, a transformer connected in the input circuit of said amplifier and arranged to 'be supplied with current from said pick-up device, a resis ,tance connected in shunt to said pick-up device and.
  • means'for including a variable portion of said resistance in shunt to the' primary of said transformer, the value of said resistance being substantially as great as the maximum reactance of said pick-up resistance connected in shunt to said piclztimes the minimum reactance of the primary of said transformer at the frequencies to be reproduced.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Electromagnetism (AREA)
  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Amplifiers (AREA)
US65472A 1924-07-29 1925-10-28 Sound-reproducing apparatus Expired - Lifetime US1599418A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
BE340865D BE340865A (enrdf_load_stackoverflow) 1925-10-28
BE337501D BE337501A (enrdf_load_stackoverflow) 1925-10-28
BE338052D BE338052A (enrdf_load_stackoverflow) 1925-10-28
US65472A US1599418A (en) 1925-10-28 1925-10-28 Sound-reproducing apparatus
FR32468D FR32468E (fr) 1924-07-29 1926-10-25 Perfectionnements à la fabrication des phonogrammes

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US65472A US1599418A (en) 1925-10-28 1925-10-28 Sound-reproducing apparatus

Publications (1)

Publication Number Publication Date
US1599418A true US1599418A (en) 1926-09-14

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ID=22062953

Family Applications (1)

Application Number Title Priority Date Filing Date
US65472A Expired - Lifetime US1599418A (en) 1924-07-29 1925-10-28 Sound-reproducing apparatus

Country Status (2)

Country Link
US (1) US1599418A (enrdf_load_stackoverflow)
BE (1) BE337501A (enrdf_load_stackoverflow)

Also Published As

Publication number Publication date
BE337501A (enrdf_load_stackoverflow)

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