GB666705A - Improvements in or relating to public address apparatus - Google Patents
Improvements in or relating to public address apparatusInfo
- 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
Links
- 239000002184 metal Substances 0.000 abstract 3
- 229910052751 metal Inorganic materials 0.000 abstract 3
- 230000008878 coupling Effects 0.000 abstract 2
- 238000010168 coupling process Methods 0.000 abstract 2
- 238000005859 coupling reaction Methods 0.000 abstract 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 abstract 1
- 239000011248 coating agent Substances 0.000 abstract 1
- 238000000576 coating method Methods 0.000 abstract 1
- 229910052802 copper Inorganic materials 0.000 abstract 1
- 239000010949 copper Substances 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B5/00—Near-field transmission systems, e.g. inductive or capacitive transmission systems
-
- 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
- H04R3/12—Circuits 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.
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)
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 |
-
1949
- 1949-01-19 GB GB155949A patent/GB666705A/en not_active Expired
Cited By (4)
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 |
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