GB666705A - Improvements in or relating to public address apparatus - Google Patents

Improvements in or relating to public address apparatus

Info

Publication number
GB666705A
GB666705A GB155949A GB155949A GB666705A GB 666705 A GB666705 A GB 666705A GB 155949 A GB155949 A GB 155949A GB 155949 A GB155949 A GB 155949A GB 666705 A GB666705 A GB 666705A
Authority
GB
United Kingdom
Prior art keywords
coil
coils
primary
loud
speakers
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
Application number
GB155949A
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.)
PAMPHONIC REPRODUCERS Ltd
Original Assignee
PAMPHONIC REPRODUCERS Ltd
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 PAMPHONIC REPRODUCERS Ltd filed Critical PAMPHONIC REPRODUCERS Ltd
Priority to GB155949A priority Critical patent/GB666705A/en
Publication of GB666705A publication Critical patent/GB666705A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B5/00Near-field transmission systems, e.g. inductive or capacitive transmission systems
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00Circuits for transducers, loudspeakers or microphones
    • H04R3/12Circuits for transducers, loudspeakers or microphones for distributing signals to two or more loudspeakers

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Circuit For Audible Band Transducer (AREA)

Abstract

666,705. Public address systems. TAYLOR, P. H., and PAMPHONIC REPRODUCERS, Ltd. March 30, 1950 [Jan. 19, 1949], No 1559/49. Class 40 (iv). [Also in Group XL (c)] In a public address system comprising one or more downwardly-directed loud-speakers which are fastened under chairs, pews, &c., and inductively coupled to an audio frequency source over adjacent primary and secondary coils, the use of intermediate amplifiers between the secondary coils and the loud-speakers to provide an adequate power output is avoided by reducing the self-inductance of each coil and hence improving the coupling coefficient, either by spacing each coil turn apart or by forming the coils from a single loop of strip or tubular metal. As shown, the primary coil 1 is located beneath the floor 2 with each turn vertically spaced about 10 inches apart, while the secondary coil comprises a single loop of verticallymounted strip metal 5 embracing a row of chairs and having a narrow portion 8 accommodating a coupling transformer 7 for a loudspeaker 9. Several primary coils may be used, each coil enclosing an area of about 1000 square feet and connected so that the currents in adjacent coil sides are in the same direction. In an alternative arrangement, the coils may be constituted by a metal coating on a wall or other surface. Where suspended loud-speakers are used, the secondary coil may be a square tunnel of copper sheet or a large diameter sheetmetal ring, and the primary loop may be wound outside the building. The primary coils are fed from an amplifier 3 and the lowfrequency coil loading is reduced by a high-pass filter or constant-impedance network. Preemphasis of the high frequencies may also be provided.
GB155949A 1949-01-19 1949-01-19 Improvements in or relating to public address apparatus Expired GB666705A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB155949A GB666705A (en) 1949-01-19 1949-01-19 Improvements in or relating to public address apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB155949A GB666705A (en) 1949-01-19 1949-01-19 Improvements in or relating to public address apparatus

Publications (1)

Publication Number Publication Date
GB666705A true GB666705A (en) 1952-02-20

Family

ID=9724081

Family Applications (1)

Application Number Title Priority Date Filing Date
GB155949A Expired GB666705A (en) 1949-01-19 1949-01-19 Improvements in or relating to public address apparatus

Country Status (1)

Country Link
GB (1) GB666705A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1038116B (en) * 1956-03-13 1958-09-04 Siemens Ag Conductor loop for inductive reception with hearing aids or the like.
US3673334A (en) * 1971-03-19 1972-06-27 Educational Service Programs I Antenna for use with an audio induction communication system
US4428078A (en) 1979-03-26 1984-01-24 The Boeing Company Wireless audio passenger entertainment system (WAPES)
EP2560295A1 (en) * 2011-08-15 2013-02-20 Sony Mobile Communications AB Using a mobile device as a hearing aid

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1038116B (en) * 1956-03-13 1958-09-04 Siemens Ag Conductor loop for inductive reception with hearing aids or the like.
US3673334A (en) * 1971-03-19 1972-06-27 Educational Service Programs I Antenna for use with an audio induction communication system
US4428078A (en) 1979-03-26 1984-01-24 The Boeing Company Wireless audio passenger entertainment system (WAPES)
EP2560295A1 (en) * 2011-08-15 2013-02-20 Sony Mobile Communications AB Using a mobile device as a hearing aid

Similar Documents

Publication Publication Date Title
GB666705A (en) Improvements in or relating to public address apparatus
GB498468A (en) Improved method of and apparatus for the transmission of speech and other sounds
CN205723108U (en) The audio-frequency transformer of low-frequency response can be realized
GB288714A (en) Improvements in telegraphy and telephony
GB495171A (en) Improvements in deaf-aids for use in cinema auditoriums or the like
GB738886A (en) Improvements in and relating to saturable reactors
GB656891A (en) Improvements in or relating to high frequency electric transformers
GB352179A (en) Speech-translating method and apparatus therefor
GB640462A (en) Improvements in and relating to electromagnetic induction apparatus
GB779156A (en) A remote control device for use with apparatus incorporating a loud speaker
GB678391A (en) Distribution of television signals or other carrier waves by wire line
JPS5525265A (en) Multiple mobile coil type speaker
GB1184619A (en) Liquid-Insulated Electrical Device, particularly Transformer or Choke Coil.
GB247774A (en) Improvements in vacuum tube systems for the transmission of high frequency signals
GB291406A (en) Improvements relating to voltage limiting arrangements
GB333460A (en) Improvements in and relating to the distribution of wireless programmes
JPS548404A (en) Talkie sending system
GB841564A (en) Television receiver scanning system
GB392524A (en) Improvements in and relating to sound reproducing devices
US1842558A (en) Amplifier energizing system
GB554367A (en) Inductance apparatus
GB551297A (en) Transformer
GB262979A (en) Improvements in wireless receiving apparatus using current from the supply mains
GB365813A (en) Improvements in or relating to aerials for eliminating local disturbances in wireless reception
GB343087A (en) Improvements in or relating to telephone transmission or like systems