EP0767553A1 - Circuit pour produire des impulsions d'interruption du son de courte durée pour un récepteur d'automobile - Google Patents

Circuit pour produire des impulsions d'interruption du son de courte durée pour un récepteur d'automobile Download PDF

Info

Publication number
EP0767553A1
EP0767553A1 EP95115583A EP95115583A EP0767553A1 EP 0767553 A1 EP0767553 A1 EP 0767553A1 EP 95115583 A EP95115583 A EP 95115583A EP 95115583 A EP95115583 A EP 95115583A EP 0767553 A1 EP0767553 A1 EP 0767553A1
Authority
EP
European Patent Office
Prior art keywords
level
signal
input
circuit arrangement
comparison stage
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.)
Granted
Application number
EP95115583A
Other languages
German (de)
English (en)
Other versions
EP0767553B1 (fr
Inventor
Juergen Ing. Grad. Wermuth
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.)
Blaupunkt Werke GmbH
Original Assignee
Blaupunkt Werke GmbH
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 Blaupunkt Werke GmbH filed Critical Blaupunkt Werke GmbH
Priority to DE59510754T priority Critical patent/DE59510754D1/de
Priority to EP19950115583 priority patent/EP0767553B1/fr
Publication of EP0767553A1 publication Critical patent/EP0767553A1/fr
Application granted granted Critical
Publication of EP0767553B1 publication Critical patent/EP0767553B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04H—BROADCAST COMMUNICATION
    • H04H20/00—Arrangements for broadcast or for distribution combined with broadcast
    • H04H20/20—Arrangements for broadcast or distribution of identical information via plural systems
    • H04H20/22—Arrangements for broadcast of identical information via plural broadcast systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04H—BROADCAST COMMUNICATION
    • H04H40/00—Arrangements specially adapted for receiving broadcast information
    • H04H40/18—Arrangements characterised by circuits or components specially adapted for receiving
    • H04H40/27—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95
    • H04H40/36—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95 specially adapted for stereophonic broadcast receiving
    • H04H40/45—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95 specially adapted for stereophonic broadcast receiving for FM stereophonic broadcast systems receiving
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04H—BROADCAST COMMUNICATION
    • H04H2201/00—Aspects of broadcast communication
    • H04H2201/10—Aspects of broadcast communication characterised by the type of broadcast system
    • H04H2201/13—Aspects of broadcast communication characterised by the type of broadcast system radio data system/radio broadcast data system [RDS/RBDS]

Definitions

  • the invention relates to a circuit arrangement for a car radio according to the preamble of claim 1.
  • Such a circuit arrangement is useful, for example, in the case of a mobile RDS receiver (radio data receiver) with which alternative transmitters are briefly checked for their reception quality. So that interference signals that occur during the duration of the check cannot reach the loudspeaker, it is necessary to briefly mute the LF signal by means of a blanking pulse. However, since an abrupt muting during an existing LF level causes cracking noises that are perceived as disturbing, measures are necessary to reduce them to such an extent that they are as imperceptible as possible.
  • the invention has for its object to provide a circuit arrangement for a car radio, with the control pulses for short-term alternative transmitter checks are generated with simultaneous muting, the muting should not be perceived by the human ear as noise.
  • the advantages achieved by the invention are, in particular, that the short-term muting takes place within the hearing shadow recognized by the circuit arrangement and caused by the decaying process of the hearing. Since frequent testing of alternative transmitters with large reception field strengths and with modulation can take place, a control provided for the selection of transmitters with a decreasing reception field strength is already informed of the transmitter landscape, so that alternative frequency tests do not have to be carried out hastily.
  • the output of an LF bandpass filter 1 provided with an amplifier stage is connected to the input of a double-path logarithmizer 2, the output of which is connected via a double-path rectifier 3 to the input of a second-order low-pass filter 4 having an amplifier stage, which has a cutoff frequency of approximately 23 Hz.
  • the output of the low pass 4 is connected to the input of an adder 5, to the input of a first time constant element 6 and to the input of a second time constant element 7.
  • the output of the adder 5 is connected to the first input A of a level comparison stage 8 designed as a logic circuit.
  • the output of the first time constant element 6 is connected to the second input B of the level comparison stage 8 and the output of the second time constant element 7 is connected to the third input C of the level comparison stage 8, the output D of which is connected to the input of a pulse shaper stage 9.
  • the adder 5 adds a DC voltage level to the input level supplied to it of, for example, 0.6 volts.
  • the first and the second time constant elements 6, 7 are designed such that their output levels change largely linearly as a function of time. A rate of change of, for example, 18 volts per second is provided for the first time constant element 6 and, for example, 1 volt per second for the second time constant element 7.
  • the pulse shaper stage 9 is designed such that it outputs a control pulse (S6) with a duration of, for example, 5 ms when it receives an input signal from the comparison stage and is then blocked for a further period of time equal to or greater than 100 ms.
  • MPX signal a multiplex signal
  • car radio not shown
  • a control pulse with a duration of approximately 5 is used for muting and for a transmitter check to be carried out during this muting time of, for example, 8 ms ms should be generated.
  • the LF signal S1 filtered out of the MPX signal by means of the bandpass filter 1 is fed to the second-order low-pass filter 4 via the two-way logarithmizer 2 and the two-way rectifier 3. 2 shows the course of such an LF signal S1 on a linear scale.
  • a signal S2 can be taken, the course of which corresponds to an envelope of the rectified and screened LF signal, the logarithmic signal S2 being amplified to a value of 1 volt per 10 dB level change.
  • the envelope signal S2, which is raised by a DC voltage level of 0.6 volt, is fed to the first input of the logic circuit 8 as a reference value level S3.
  • the second input B of the logic circuit 8 is fed via the first time constant element 6, the time constant of which largely corresponds to the time constant for swinging-in and swinging-out processes of the human ear, as a hearing-related signal level S4.
  • the third input C of the logic circuit 8 is supplied with the signal taken from the second time constant element 7 as the mean value level S5.
  • the levels S2 and S3 represent the envelope curve profile of the LF signal S1. If, as shown, the level S3 at the first input A of the logic circuit 8 is lower than the level S4 at the second input B at point a and the level S3 at point b is lower than the level S5, output D of the logic circuit 8 is produced a signal that starts the pulse shaper stage 9. This in turn now emits a control pulse with a duration of approximately 5 ms and is then blocked for further controls for a duration of equal to or greater than 100 ms.
  • the level increase by means of the adder 5 in such a way that the envelope level S2 is on the one hand about 6 dB below the ear curve level S4 and on the other hand about 6 dB below the mean level S5.
  • the level increase of 0.6 volts selected in the present exemplary embodiment can be generated in a practical circuit by means of a base-emitter threshold of a transistor.
  • the logarithmization of the LF signal ensures that the different volume (modulation deviation) of the transmitter has no effect on a changing behavior of the system. Only the dynamics of the modulation is the criterion for controlling the short mute and check times.
  • the circuit arrangement according to the invention is also based on the fact that after a hearing shade has been detected - not within about 8 ms - the level rises again. Practical tests have shown that about 8% of the 8 ms muting lies in the so-called hearing shadow. This means that only about every twentieth to thirtieth muting could be heard.
  • the logic provides the processor with a window of about 3 to 5 ms in length for the start of the AF test. If you miss this window, you have to wait for the next one. If there are time problems with critical reception situations, it is up to the software to allow AF jumps without approval.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Noise Elimination (AREA)
  • Amplifiers (AREA)
EP19950115583 1995-10-02 1995-10-02 Circuit pour produire des impulsions d'interruption du son de courte durée pour un récepteur d'automobile Expired - Lifetime EP0767553B1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE59510754T DE59510754D1 (de) 1995-10-02 1995-10-02 Schaltungsanordnung für ein Autoradio zur Erzeugung kurzzeitiger Stummschaltimpulse
EP19950115583 EP0767553B1 (fr) 1995-10-02 1995-10-02 Circuit pour produire des impulsions d'interruption du son de courte durée pour un récepteur d'automobile

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP19950115583 EP0767553B1 (fr) 1995-10-02 1995-10-02 Circuit pour produire des impulsions d'interruption du son de courte durée pour un récepteur d'automobile

Publications (2)

Publication Number Publication Date
EP0767553A1 true EP0767553A1 (fr) 1997-04-09
EP0767553B1 EP0767553B1 (fr) 2003-07-23

Family

ID=8219681

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19950115583 Expired - Lifetime EP0767553B1 (fr) 1995-10-02 1995-10-02 Circuit pour produire des impulsions d'interruption du son de courte durée pour un récepteur d'automobile

Country Status (2)

Country Link
EP (1) EP0767553B1 (fr)
DE (1) DE59510754D1 (fr)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0507096A2 (fr) * 1991-03-29 1992-10-07 Pioneer Electronic Corporation Récepteur RDS
DE4233758C1 (de) * 1992-10-07 1994-01-27 Blaupunkt Werke Gmbh Rundfunkempfänger
EP0597492A1 (fr) * 1992-11-13 1994-05-18 CLARION Co., Ltd. Récepteur pour radiodiffusion RDS
DE4316683A1 (de) * 1993-05-16 1994-11-17 H U C Elektronik Gmbh Verfahren und Schaltungsanordnung zum Rundfunkempfang

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0507096A2 (fr) * 1991-03-29 1992-10-07 Pioneer Electronic Corporation Récepteur RDS
DE4233758C1 (de) * 1992-10-07 1994-01-27 Blaupunkt Werke Gmbh Rundfunkempfänger
EP0597492A1 (fr) * 1992-11-13 1994-05-18 CLARION Co., Ltd. Récepteur pour radiodiffusion RDS
DE4316683A1 (de) * 1993-05-16 1994-11-17 H U C Elektronik Gmbh Verfahren und Schaltungsanordnung zum Rundfunkempfang

Also Published As

Publication number Publication date
EP0767553B1 (fr) 2003-07-23
DE59510754D1 (de) 2003-08-28

Similar Documents

Publication Publication Date Title
DE4021969C2 (de) Automatische Lautstärkeregelung
EP1241797A2 (fr) Procédé de commande d' un système de reproduction sonore à plusieurs canaux et système de reproduction sonore à plusieurs canaux
DE3850289T2 (de) Automatische Lautstärkeregelungsschaltung.
DE3427473A1 (de) Diversityempfaenger
DE69522050T2 (de) AM-Funkempfänger
DE2237404C2 (de) Schaltung zum Bewerten der Qualität von NF-Signalen
DE69700173T2 (de) Empfänger mit automatischer Rauschsperre
DE1158560B (de) UEbertragungssystem fuer Signaluebertragung durch Impulskodemodulation und dabei anzuwendende Sender und Empfaenger
EP0027519A1 (fr) Montage de commande automatique du volume sonore d'un haut-parleur en fonction du niveau de bruit ambiant
DE3927765C2 (fr)
DE1900639A1 (de) Signalkompressor und -expander
DE3220758A1 (de) Verfahren zur selbsttaetigen anpassung der lautstaerke und der dynamik elektroakustischer signale an den am hoerort auftretenden stoerschallpegel
DE2507986A1 (de) Tonfrequenz-unterdrueckungssystem
EP0767553A1 (fr) Circuit pour produire des impulsions d'interruption du son de courte durée pour un récepteur d'automobile
DE4421694B4 (de) Schaltungsanordnung für ein Autoradio zur Erzeugung kurzzeitiger Stummschaltimpulse
DE2945783C2 (de) Tonsignal-Verstärkerschaltung
EP1271816B1 (fr) Procédé de recherche d'une fréquence dans un récepteur radio
EP0653850A2 (fr) Circuit pour reconnaître l'interférence d'un canal adjacent
DE3504407A1 (de) Frequenznachlaufeinrichtung in einem stereo-fm-rundfunkempfaenger
DE2752657C2 (fr)
DE2912566A1 (de) Ton-decodierschaltung
DE2934956A1 (de) Rauschunterdrueckungssystem
DE2539769C3 (de) Digitale Pulsmodulation mit Dynamikbegrenzung
DE3521099C2 (fr)
DE3883485T2 (de) Hörverbesserungsschaltung im Falle eines Trägerschwunds in einem schmalbandigen FM/PM-Empfänger.

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: A1

Designated state(s): DE FR GB IT

17P Request for examination filed

Effective date: 19971009

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): DE FR GB IT

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REF Corresponds to:

Ref document number: 59510754

Country of ref document: DE

Date of ref document: 20030828

Kind code of ref document: P

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 20031028

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

Ref country code: DE

Payment date: 20031215

Year of fee payment: 9

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: 20040426

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 NON-PAYMENT OF DUE FEES

Effective date: 20050503

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

Ref country code: IT

Payment date: 20081028

Year of fee payment: 14

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

Ref country code: FR

Payment date: 20081021

Year of fee payment: 14

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

Ref country code: GB

Payment date: 20081024

Year of fee payment: 14

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20100630

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: 20091102

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: 20091002

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: 20091002