EP0777403B1 - A system of sound diffusion, particularly for large spaces - Google Patents

A system of sound diffusion, particularly for large spaces Download PDF

Info

Publication number
EP0777403B1
EP0777403B1 EP96203376A EP96203376A EP0777403B1 EP 0777403 B1 EP0777403 B1 EP 0777403B1 EP 96203376 A EP96203376 A EP 96203376A EP 96203376 A EP96203376 A EP 96203376A EP 0777403 B1 EP0777403 B1 EP 0777403B1
Authority
EP
European Patent Office
Prior art keywords
terminal
direct
current voltage
signal
secondary winding
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
EP96203376A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0777403A2 (en
EP0777403A3 (en
Inventor
Angelo Martinazzi
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of EP0777403A2 publication Critical patent/EP0777403A2/en
Publication of EP0777403A3 publication Critical patent/EP0777403A3/en
Application granted granted Critical
Publication of EP0777403B1 publication Critical patent/EP0777403B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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

Definitions

  • the present invention relates to a system of sound diffusion, particularly for large spaces.
  • systems made with analog technology that have a central wide-band amplifier that amplifies a source signal, for example a pre-amplified signal originating in a microphone, and a plurality of loudspeakers distributed in the space in question.
  • Each loudspeaker in addition to comprising an electro-acoustical transducer, also has a local amplifier that amplifies the signal from the central amplifier bringing it to a level suitable for driving the electro-acoustical transducer.
  • each loudspeaker to the central amplifier thus requires at least two pairs of wires, a first pair for the wide-band amplified signal, and a second pair to supply the local amplifiers with the necessary voltage. This involves fairly high installation costs.
  • US-A-5081440 discloses a bus coupler for coupling transmission and receiving stations to a two-conductor bus which feeds d-c current for coupling the on-board networks of the stations.
  • an object of the present invention is that of providing a system of sound diffusion that, while still made in analog technology, requires only one pair of wires for the connection of each loudspeaker to the central amplifier, that has a low production cost and that is simple to assemble and to install.
  • the present invention it is possible to provide a system of sound diffusion in analog technology that requires only one pair of wires for the connection of a central amplification device to a peripheral electro-acoustical transducer device, on said pair of wires it being possible to send both the sound signal and a supply voltage of a local amplifier of the peripheral transducer device.
  • the system comprises a transmitter transducer 1 and a plurality (two in the example of the figure) of receiver transducers 2.
  • the transmitter transducer 1 comprises a stabilized power unit 3 that, starting from the mains alternating-current voltage (220 VAC) generates at output, across a positive terminal 8 and a negative terminal 9, a stabilized direct-current voltage V1 of about 24 VDC , whose value can, however, be regulated from the outside for the reasons that will be explained later.
  • the positive terminal 8 of the power unit 3 is connected to an input terminal VI of a voltage regulator 4 with three terminals (known in itself) that, between an output terminal VO and a reference voltage GND of the entire circuit represented by the potential of the negative terminal 9 of the power unit 3, supplies a regulated direct-current voltage V2 of about 18 VDC.
  • the third terminal of the regulator 4 is connected to the reference voltage of the circuit.
  • Condensers C1 and C2 with typical values of 2200 ⁇ F and 1000 ⁇ F, respectively, are connected between the input terminal VI of the regulator 4 and the reference voltage GND, and between the output terminal VO of the regulator 4 and the reference voltage GND, respectively; the condensers C1 and C2 perform in a known manner filtering functions of the input and output voltages of the regulator 4.
  • a 24-volt buffer battery 6 that cuts in to supply the circuit if the line alternating-current voltage were to drop off; a diode 7 connected in series between the positive terminal of the battery 6 and the positive terminal 8 of the power unit 3 insulates the battery 6 from the rest of the circuit when the voltage V1 is above about 23.5 VDC.
  • the voltage V2 supplies a power amplifier 5, for example of the type commercially identified by TDA1905.
  • the amplifier 5 has an invertent terminal 10 and non-invertent terminal 11; the invertent terminal 10 is connected to the reference voltage GND and to a first signal input terminal 12 of the transmitter transducer 1; the non-invertent terminal 11 is connected, through a condenser C3 (for example with a value of 22 ⁇ F) and a potentiometer R1 (for example with a value of 220 ohms), to a second signal input terminal 13 of the transmitter transducer 1.
  • An output terminal 14 of the amplifier 5 is connected, through three coupling condensers C4, C5 and C6 that in this embodiment have values of 1000 ⁇ F, 2200 ⁇ and 2200 ⁇ F, respectively, to a terminal 15 of a primary winding 16 of a line-coupling transformer 17, the other terminal 18 of the primary winding 16 being connected to the positive output terminal 8 of the power unit 3.
  • a resistance R2 that, with the condensers C5 and C6, acts as a high-pass filter for the amplified signal at output from the amplifier 5.
  • a secondary winding 19 of the transformer 17 has a terminal 20 connected, in common with the terminal 18 of the primary 16, to the positive output terminal 8 of the power unit 3.
  • a tap 21 whose position of insertion can be varied along the secondary winding 19 is coupled in feedback, by means of a condenser C7 of 0.18 ⁇ F, to the common terminal of the condensers C4 and C5.
  • the secondary winding 19 of the transformer 17 is wound so as to have phase inversion between the signal on the primary winding 16 and the signal induced on the secondary winding 19.
  • the transmitter transducer 1 is connected to each of the receiver transducers 2 by means of a respective transmission line 22 with two wires, consisting of normal electrical conductors.
  • a first wire 23 of the line 22 is connected to a central point 24 of the secondary winding 19 of the transformer 17; a second wire 24 of the line 22 is connected to the reference voltage GND.
  • the receiver transducers 2 comprise a transformer 25 having a primary winding 26 with a first terminal 27 connected to the wire 23 of the line 22, and thus to the central point 24 of the secondary winding 19 of the transformer 17 in the transmitter transducer 1, and a second terminal 28 coupled, by means of a condenser C8 of 2200 ⁇ F, to the wire 24 of the line 22, and thus to the reference voltage GND.
  • the terminal 28 of the primary winding 26 of the transformer 25 is connected to an input terminal VI of a voltage regulator 29 with three terminals identical to the regulator 4 of the transmitter transducer 1 and that supplies, on an output terminal VO, a regulated voltage V3 of about 18 volts that supplies an amplifier 30, for example identical to the amplifier 5 of the transmitter transducer 1.
  • a third terminal of the regulator 29 is connected to the terminal of the condenser C8 connected to the wire 24, that is to the reference voltage GND.
  • a condenser C9 of 1000 ⁇ F connected between the output terminal VO of the regulator 29 and the reference voltage GND.
  • the condensers C8 and C9 perform functions substantially similar to those performed by the condensers C1 and C2 of the transmitter transducer 1, in addition the condenser C8 allows the signal to be closed again toward the reference voltage GND.
  • the transformer 25 also has a secondary winding 32, wound in phase opposition to the primary winding.
  • a first terminal 31 of the secondary winding 32 of the transformer 25 is connected to the terminal 28 of the primary winding 26.
  • a second terminal 33 of the secondary winding 32 is coupled, by means-of two condensers C10 and C11 for example of 1000 ⁇ F, a potentiometer R3 and a condenser C12 for example of 22 ⁇ F, to a non-invertent input 34 of the amplifier 30; between the common terminal of the condensers C10 and C11 and the reference voltage GND there is connected a resistance R4, for example of 47 kohms, that acts as an impedance adaptor.
  • a central point 35 of the secondary winding 32 is also coupled, by means of a condenser C13 for example of 0.18 ⁇ F, the potentiometer R3 and the condenser C12, to the non-invertent input 34 of the amplifier 30; the central point 35 is also connected, by means of a resistor R5 for example of 10 kohms, to the terminal 31 of the secondary winding 32.
  • the invertent input 36 of the amplifier 30 is connected to the reference voltage GND, and an output terminal 37 of the amplifier 30 drives, through a condenser C14, a loudspeaker (or a set of loudspeakers) 38.
  • the stabilized power unit 3 generates, starting from the alternating-current mains voltage (typically 220 VAC) a stabilized voltage V1 of about 24 volts; the output voltage V1 of the power unit 3 can be regulated (increased) from the outside so as to compensate for the drop in voltage along the line 22 due to the resistance of the wires 23 and 24; moreover, the amp rating of the power unit 3 depends on the total number of receiver transducers that the transmitter transducer 1 has for driving, that is on the total direct current that flows along the line 22.
  • the voltage V1 is taken by the regulator 4 to the regulated voltage V2 of about 18 volts necessary to supply the power amplifier 5 so that the latter can provide an output power of about 4 watts.
  • the source signal Vin to be amplified signal having an amplitude of the order of a few mW that is for example generated by any microphone pre-amplifier with output equal to 0 dBm.
  • the output signal of the amplifier 5 is applied, after being filtered, to the terminal 15 of the primary winding 16 of the transformer 17; to the other terminal 18 of the primary winding 16 there is also applied the direct-current voltage V1, so that on the primary winding 16 of the transformer 17, between the terminals 18 and 15, there is present a signal in alternating current (the signal at output of the amplifier 5) superimposed on a direct-current component (the voltage V1).
  • the primary winding 26 of the corresponding transformer 25 acts as a block impedance that separates the direct-current component present on the transmission line 22 of the signal.
  • the direct-current component that is seen again across the condenser C8, is taken to a regulated voltage of 18 volts by the regulator 29, a voltage that is necessary to supply the amplifier 30 so as to allow an amplification of about 4 watts.
  • the alternating-current signal present on the line 22 is on the other hand induced, in phase opposition and raised in voltage with a ratio of about 1 to 2, in the secondary winding 33; from the secondary winding 33 there are taken, on the terminal 33 and on the point 35, two signals that are coupled by means of the condensers C10, C11 and C13, respectively, to the input of the amplifier 30; the condensers C10 and C11 form part of a low-pass filter, while the condenser C13 forms part of a high-pass filter.
  • the total signal present at the input of the amplifier thus consists of two in-phase signals in separate frequency bands and delayed one with respect to the other due to their different take-off points on the secondary winding. Said total signal is amplified by the amplifier 30, that drives the loudspeaker 38.
  • the system according to the present invention can also be used for the diffusion of high-fidelity stereophonic sound, as well as in high-powered audio systems.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)
EP96203376A 1995-11-29 1996-11-29 A system of sound diffusion, particularly for large spaces Expired - Lifetime EP0777403B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITMI952485 1995-11-29
IT95MI002485A IT1278525B1 (it) 1995-11-29 1995-11-29 Impianto di diffusione sonora,particolarmente per grandi ambienti

Publications (3)

Publication Number Publication Date
EP0777403A2 EP0777403A2 (en) 1997-06-04
EP0777403A3 EP0777403A3 (en) 2001-06-27
EP0777403B1 true EP0777403B1 (en) 2003-10-01

Family

ID=11372616

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96203376A Expired - Lifetime EP0777403B1 (en) 1995-11-29 1996-11-29 A system of sound diffusion, particularly for large spaces

Country Status (3)

Country Link
EP (1) EP0777403B1 (it)
DE (1) DE69630187D1 (it)
IT (1) IT1278525B1 (it)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006006862A1 (de) * 2006-02-13 2007-08-30 Technisat Digital Gmbh Schaltungsanordnung zum Betrieb eines Lautsprechers

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6015026A (en) * 1997-06-06 2000-01-18 Owens-Corning Fiberglas Technology, Inc. Acoustical diffuser assembly and method of installation
AUPO862197A0 (en) 1997-08-15 1997-09-11 Leisuretech Electronics Pty Ltd A distributed stereo system

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0365696A1 (de) * 1988-10-24 1990-05-02 Siemens Aktiengesellschaft Übertragungssystem

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1499983A (en) * 1975-03-04 1978-02-01 Gen Electric Co Ltd Audio-frequency amplifiers
US4691345A (en) * 1986-05-12 1987-09-01 Rice Multiphones, Inc. Multifunction two line telephone system
GB2265265A (en) * 1992-03-11 1993-09-22 Chevin Associates Limited Converters, inverters and power supplies

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0365696A1 (de) * 1988-10-24 1990-05-02 Siemens Aktiengesellschaft Übertragungssystem

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006006862A1 (de) * 2006-02-13 2007-08-30 Technisat Digital Gmbh Schaltungsanordnung zum Betrieb eines Lautsprechers

Also Published As

Publication number Publication date
DE69630187D1 (de) 2003-11-06
EP0777403A2 (en) 1997-06-04
EP0777403A3 (en) 2001-06-27
ITMI952485A1 (it) 1997-05-29
ITMI952485A0 (it) 1995-11-29
IT1278525B1 (it) 1997-11-24

Similar Documents

Publication Publication Date Title
US4414433A (en) Microphone output transmission circuit
US4536888A (en) Voice communication instrument system with line-powered receiver conditioning circuit
US7974426B2 (en) IC chip type hearing aid module for mobile communication terminal
TWI509986B (zh) 聲訊放大器及將聲訊放大器變組態的方法
CA2571245A1 (en) Amplifier for unshielded twisted pair wire signals
EP0777403B1 (en) A system of sound diffusion, particularly for large spaces
KR20020064769A (ko) 출력 트랜스포머를 갖는 증폭기
EP0738047A2 (en) Portable radio telephone device
US20080260179A1 (en) Active loudspeaker
US5459792A (en) Audio input circuit for voice recognition
KR20000029950A (ko) 전자오디오신호의고조파개선장치및방법
JPH05267944A (ja) トランス駆動回路
EP2190114B1 (en) Local broadcasting system
US3080454A (en) Intra-plant voice communication system
CN103095238A (zh) 音频输出放大器
EP0186214A2 (en) Battery-feed circuit for exchange
US5530770A (en) Multiple output transformers network for sound reproducing system
US9467110B1 (en) Electronic system of a hybrid amplifier
JPH08205277A (ja) マイクロホンの電源供給回路
KR100662792B1 (ko) 전력선 노이즈 제거회로
GB2218594A (en) Induction loop driving ampliflier
KR20150041828A (ko) Ｐｌｃ 조명스피커 시스템
JP2004112161A (ja) 音声出力装置
JP2011071885A (ja) 安定化電源音響出力装置
SU1656690A1 (ru) Устройство дл двустороннего усилени тональной частоты

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE ES FR GB IT

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE ES FR GB IT

RIC1 Information provided on ipc code assigned before grant

Free format text: 7H 04R 3/00 A, 7H 04R 27/00 B

17P Request for examination filed

Effective date: 20010728

17Q First examination report despatched

Effective date: 20021126

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE ES FR GB IT

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 69630187

Country of ref document: DE

Date of ref document: 20031106

Kind code of ref document: P

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040103

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20040112

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20040702

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20041124

Year of fee payment: 9

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20051129

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20051129

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20071025

Year of fee payment: 12

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20090731

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20101019

Year of fee payment: 15

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20081130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20121129