US3222455A - Aural stereophonic balance indicator - Google Patents

Aural stereophonic balance indicator Download PDF

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Publication number
US3222455A
US3222455A US198834A US19883462A US3222455A US 3222455 A US3222455 A US 3222455A US 198834 A US198834 A US 198834A US 19883462 A US19883462 A US 19883462A US 3222455 A US3222455 A US 3222455A
Authority
US
United States
Prior art keywords
secondary windings
switch
aural
output
load
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
US198834A
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English (en)
Inventor
Edwin R Golik
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
Application filed by General Electric Co filed Critical General Electric Co
Priority to US198834A priority Critical patent/US3222455A/en
Priority to OA50703A priority patent/OA00614A/fr
Application granted granted Critical
Publication of US3222455A publication Critical patent/US3222455A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04S—STEREOPHONIC SYSTEMS 
    • H04S7/00—Indicating arrangements; Control arrangements, e.g. balance control
    • H04S7/40—Visual indication of stereophonic sound image

Definitions

  • this objective is achieved by the provision of a switch that connects the outputs of the two channels in a series circuit in such relative polarities that the voltages in the outputs tend to cancel.
  • the channel gains are adjusted so as to be equal, the output voltages of the channels cancel, and an aural null is produced in the sounding emanating from the acoustic transducers for each channel.
  • the balancing circuit set up by the switch may cause the amplifier to oscillate as the desired aural null is approached, thus making it difiicult to secure the desired balanced condition.
  • Input terminals 2 and 4 are respectively connected to ungrounded ends of balancing potentiometers 6 and 8.
  • the movable contact arms 10 and 12 are ganged together in such a manner that one moves farther from ground as the other moves toward it and vice versa, as indicated by the arrows.
  • Amplifiers 14 and 16 have their inputs respectively connected to primary windings 18 and 20 of output transformers 22 and 24. Positive direct current operating potential is supplied to the amplifiers 14 and 16 by connection of a suitable source between ground and the ends of the secondary windings 18 and 20 that are remote from the amplifiers.
  • Secondary windings 26 and 28 of the transformers 22 and 24 have ends of like polarity connected to a point of reference potential such as ground.
  • load impedances herein shown as voice coils 36 and 38 for loudspeakers 40 and 42, are connected in parallel with the secondary Windings 18 and 20.
  • the switch 30 When the switch 30 is closed, the electrical connections are conventional, but the provision of a switch which enables the ground connection to the junction of the voice coils 36 and 38 to be broken is novel and is a part of this invention and operates in the following manner.
  • the switch 30 To balance the relative gains of the two channels, the switch 30 is opened, as shown, and if the signals applied to the input terminals 2 and 4 are not known to be identical a switch 44 is closed so as to connect the terminals 2 and 4 together and thus apply identical signals to the potentiometers 6 and 8.
  • the switches 44 and 30 can be mechanically connected so that closing one 3,222,455 Patented Dec. 7, 1965 opens the other.
  • the secondary windings 26 and 28 and the voice coils 36 and 38 form a closed loop in which the audio voltages inducted in the secondary windings 18 and 20 oppose each other.
  • the gains of the channels are unequal, one of these induced audio voltages will be greater than the other with the result that sound will emanate from both of the loudspeakers 40 and 42.
  • the volume of the sound increases with the degree of imbalance. Equating the gains of the two channels with a means such as the balance control potentiometers 6 and 8, causes the audio voltages induced in the secondary windings 26 and 28 to be substantially identical. In this conditon substantially no current flows in the loop 26, 28, 36 and 38, and hence the loudspeakers receive no energy.
  • an aural null is produced in the sound emanating from the loudspeakers 40 and 42.
  • the polarities of the secondary windings 26 and 28 indicate the polarities of the audio signal voltages produced across the secondary windings where the same signal is applied to each of the terminals 2 and 4. If the channels are identical, the polarities are the same as the windings sense of the secondary windings 26 and 28 with respect to the primary windings 18 and 20.
  • a circuit for aiding in indicating where the gains of two separate audio signal channels are in balance comprising a first channel having a first output transformer, a second channel having a second output transformer, each of said transformers having a secondary winding with a predetermined polarity, means electrically connecting an end of one of said secondary windings to an end of like polarity of the other of said secondary windings, first and Second load irnpedances, and a single pole single throw switch connected so that said first and second load irnpedances are respectively connected in parallel with said secondary windings when said switch is closed and said secondary windings and said load impedances are connected in series when said switch is open.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)
US198834A 1962-05-31 1962-05-31 Aural stereophonic balance indicator Expired - Lifetime US3222455A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US198834A US3222455A (en) 1962-05-31 1962-05-31 Aural stereophonic balance indicator
OA50703A OA00614A (fr) 1962-05-31 1964-12-02 Perfectionnement aux dispositifs d'équilibrage pour chaînes stéréophoniques.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US19906262A 1962-05-31 1962-05-31
US198834A US3222455A (en) 1962-05-31 1962-05-31 Aural stereophonic balance indicator

Publications (1)

Publication Number Publication Date
US3222455A true US3222455A (en) 1965-12-07

Family

ID=26894189

Family Applications (1)

Application Number Title Priority Date Filing Date
US198834A Expired - Lifetime US3222455A (en) 1962-05-31 1962-05-31 Aural stereophonic balance indicator

Country Status (2)

Country Link
US (1) US3222455A (fr)
OA (1) OA00614A (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3382298A (en) * 1964-12-17 1968-05-07 Union Carbide Canada Ltd Stress-crack resistant polyethylene containing a polyvinyl acetal
US4503554A (en) * 1983-06-03 1985-03-05 Dbx, Inc. Stereophonic balance control system
US4594561A (en) * 1984-10-26 1986-06-10 Rg Dynamics, Inc. Audio amplifier with resistive damping for minimizing time displacement distortion
US4856065A (en) * 1987-02-27 1989-08-08 Pioneer Electronic Corporation Power fader for a loudspeaker system
US5434921A (en) * 1994-02-25 1995-07-18 Sony Electronics Inc. Stereo image control circuit
US6219424B1 (en) * 1998-05-04 2001-04-17 Hunter Area Health Service Electronic stereophonic amplifier

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US769638A (en) * 1900-11-28 1904-09-06 Gen Electric Regulation of electric circuits.
US2393885A (en) * 1944-12-23 1946-01-29 Us Government Electroacoustic binaural listening system
US2982452A (en) * 1960-02-23 1961-05-02 H E Anderson Company Apparatus for making bows
US3001019A (en) * 1959-10-26 1961-09-19 Capitol Records Stereo system
FR1291584A (fr) * 1961-03-07 1962-04-27 Thomson Houston Comp Francaise Perfectionnements aux équipements stéréophoniques

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US769638A (en) * 1900-11-28 1904-09-06 Gen Electric Regulation of electric circuits.
US2393885A (en) * 1944-12-23 1946-01-29 Us Government Electroacoustic binaural listening system
US3001019A (en) * 1959-10-26 1961-09-19 Capitol Records Stereo system
US2982452A (en) * 1960-02-23 1961-05-02 H E Anderson Company Apparatus for making bows
FR1291584A (fr) * 1961-03-07 1962-04-27 Thomson Houston Comp Francaise Perfectionnements aux équipements stéréophoniques

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3382298A (en) * 1964-12-17 1968-05-07 Union Carbide Canada Ltd Stress-crack resistant polyethylene containing a polyvinyl acetal
US4503554A (en) * 1983-06-03 1985-03-05 Dbx, Inc. Stereophonic balance control system
US4594561A (en) * 1984-10-26 1986-06-10 Rg Dynamics, Inc. Audio amplifier with resistive damping for minimizing time displacement distortion
US4856065A (en) * 1987-02-27 1989-08-08 Pioneer Electronic Corporation Power fader for a loudspeaker system
US5434921A (en) * 1994-02-25 1995-07-18 Sony Electronics Inc. Stereo image control circuit
US6219424B1 (en) * 1998-05-04 2001-04-17 Hunter Area Health Service Electronic stereophonic amplifier

Also Published As

Publication number Publication date
OA00614A (fr) 1966-07-15

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