KR900015501A - Excessive sound pressure prevention circuit in telephone - Google Patents

Excessive sound pressure prevention circuit in telephone Download PDF

Info

Publication number
KR900015501A
KR900015501A KR1019890003505A KR890003505A KR900015501A KR 900015501 A KR900015501 A KR 900015501A KR 1019890003505 A KR1019890003505 A KR 1019890003505A KR 890003505 A KR890003505 A KR 890003505A KR 900015501 A KR900015501 A KR 900015501A
Authority
KR
South Korea
Prior art keywords
circuit
resistor
varistor
capacitor
node
Prior art date
Application number
KR1019890003505A
Other languages
Korean (ko)
Other versions
KR910006052B1 (en
Inventor
박성규
Original Assignee
강진구
삼성전자 주식회사
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 강진구, 삼성전자 주식회사 filed Critical 강진구
Priority to KR1019890003505A priority Critical patent/KR910006052B1/en
Priority to GB9006335A priority patent/GB2231236B/en
Publication of KR900015501A publication Critical patent/KR900015501A/en
Application granted granted Critical
Publication of KR910006052B1 publication Critical patent/KR910006052B1/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/738—Interface circuits for coupling substations to external telephone lines
    • H04M1/74—Interface circuits for coupling substations to external telephone lines with means for reducing interference; with means for reducing effects due to line faults
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
    • H04M1/6033—Substation equipment, e.g. for use by subscribers including speech amplifiers for providing handsfree use or a loudspeaker mode in telephone sets

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
  • Telephone Function (AREA)

Abstract

내용 없음.No content.

Description

전화기에 있어서 과도음압 방지회로Excessive sound pressure prevention circuit in telephone

본 내용은 요부공개 건이므로 전문내용을 수록하지 않았음Since this is an open matter, no full text was included.

제5도는 본 발명에 따른 회로도,5 is a circuit diagram according to the present invention,

제6도는 본 발명에 따른 제5도의 바리스터(VR60)을 다이오드로 구성한 예시도,6 is a diagram illustrating a diode of the varistor VR60 of FIG. 5 according to the present invention;

제7도는 본 발명에 따른 제3기준전압 결정 예시도.7 is an exemplary view of determining a third reference voltage according to the present invention.

Claims (3)

마이크(Mic)와 연결된 제1증폭회로(10)와, 상기 제1증폭회로(10)의 출력신호를 증폭하는 제2증폭회로(20)와, 상기 제2증폭회로(20) 및 키세트 측 트랜스포머(70)와연결되고 저항(R75), 캐피시터(70)로 구성된 입출력회로(50)와 , 상기 입출력회로(50)와 연결되어 수신신호를 증폭하는 제3증폭회로(30)를 구비한 전화기의 과도음압방지회로에 있어서, 상기 제3증폭회로(30)의 출력단에 캐패시터(C78)을 연결하여, 바리스터(VR60)의 일측을 제1노드(41)에 연결하고, 상기 바리스터(VR60)의 타측에 제3기준전압(Vret1)이 인가되도록 제2노드(43)을 연결하여, 상기 제1노드(41)로부터 저항(R77)을 접속하여 연산증폭기(OP4)의 반전단에 연결하고, 상기 제2노드(43)를 연산증폭기(OP4)의 비반전단(+)에 연결하며, 상기 연산증폭기(OP4)의 반전단(-)과 출력단간에 저항(R78)과 캐피시터(C77)을 병렬로 결합하고 출력단에 캐패시터(C80)을 통해 핸드세트 스피커(SPK)가 연결 되도록 구성된 제4증폭회로(40)로 구성됨을 특징으로 하는 회로.A first amplifier circuit 10 connected to a microphone, a second amplifier circuit 20 for amplifying an output signal of the first amplifier circuit 10, the second amplifier circuit 20, and a key set A telephone having an input / output circuit 50 connected to the transformer 70 and composed of a resistor R75 and a capacitor 70 and a third amplification circuit 30 connected to the input / output circuit 50 to amplify a received signal. In the transient negative pressure suppression circuit of the circuit, a capacitor C78 is connected to the output terminal of the third amplification circuit 30, and one side of the varistor VR60 is connected to the first node 41, and the varistor VR60 of the varistor VR60 is connected. The second node 43 is connected to the other side to apply the third reference voltage Vret1, the resistor R77 is connected from the first node 41, and connected to the inverting terminal of the operational amplifier OP4. The second node 43 is connected to the non-inverting terminal (+) of the operational amplifier OP4, and the resistor R78 and the capacitor C77 are paralleled between the inverting terminal (-) and the output terminal of the operational amplifier OP4. Circuit, characterized by consisting of a fourth amplifier circuit (40) configured to be coupled to the handset speaker (SPK) connected via a capacitor (C80) to the output terminal. 제1항에 있어서, 상기 저항(R78)의 값이 저항 (R77)의 값보다 2배가 되도록 구성됨을 특징으로 하는 회로.2. A circuit according to claim 1, characterized in that the value of the resistor (R78) is configured to be twice the value of the resistor (R77). 제1항에 있어서, 상기 바리스터(VR60)를 다이오드(D81,D82)로 구성함을 특지으로하는 회로.The circuit according to claim 1, characterized in that the varistor (VR60) is composed of diodes (D81, D82). ※ 참고사항 : 최초출원 내용에 의하여 공개하는 것임.※ Note: The disclosure is based on the initial application.
KR1019890003505A 1989-03-21 1989-03-21 Transient voice pressure preventing circuit in telephone KR910006052B1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
KR1019890003505A KR910006052B1 (en) 1989-03-21 1989-03-21 Transient voice pressure preventing circuit in telephone
GB9006335A GB2231236B (en) 1989-03-21 1990-03-21 Preventing acoustic shock in a telephone

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1019890003505A KR910006052B1 (en) 1989-03-21 1989-03-21 Transient voice pressure preventing circuit in telephone

Publications (2)

Publication Number Publication Date
KR900015501A true KR900015501A (en) 1990-10-27
KR910006052B1 KR910006052B1 (en) 1991-08-12

Family

ID=19284671

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1019890003505A KR910006052B1 (en) 1989-03-21 1989-03-21 Transient voice pressure preventing circuit in telephone

Country Status (2)

Country Link
KR (1) KR910006052B1 (en)
GB (1) GB2231236B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AUPR604201A0 (en) * 2001-06-29 2001-07-26 Hearworks Pty Ltd Telephony interface apparatus
AU2002318963B2 (en) * 2001-06-29 2006-11-02 Hearworks Pty Ltd Digital signal processing system and method for a telephony interface apparatus

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4327250A (en) * 1979-05-03 1982-04-27 Electro Audio Dynamics Inc. Dynamic speaker equalizer
EP0095902A1 (en) * 1982-05-28 1983-12-07 British Broadcasting Corporation Headphone level protection circuit
EP0128894A1 (en) * 1982-12-15 1984-12-27 VAN BENTUM, Abraham Jean Pierre Auditory protection apparatus against sudden overnormal sound volumes

Also Published As

Publication number Publication date
GB2231236B (en) 1993-09-29
KR910006052B1 (en) 1991-08-12
GB9006335D0 (en) 1990-05-16
GB2231236A (en) 1990-11-07

Similar Documents

Publication Publication Date Title
KR900015564A (en) Noise reduction receiver unit
WO2002073792A3 (en) An electret condensor microphone preamplifier that is insensitive to leakage currents at the input
KR910016139A (en) Active filter
US3691311A (en) Telephone user set
KR900015501A (en) Excessive sound pressure prevention circuit in telephone
KR840004833A (en) Integrated Circuit Amplifiers for High Impedance Microphones
KR910010831A (en) Circuitry for detecting output distortion of the last stage of an audio device
KR850002188A (en) cellphone
KR910007238A (en) Amplification circuit
KR920011051A (en) Isolated Amplifier Circuit
KR920005458A (en) Amplification circuit
KR840001014A (en) Amplification furnace
KR960039772A (en) Call connection circuit of telephone handset
KR840008728A (en) Emitter Follower SEPP Circuit
SU1633509A1 (en) Sound-to-current converter
KR890008386Y1 (en) Telephone receiver
GB1525964A (en) Telephone microphone
KR900007558Y1 (en) Apparatus for muting speakers's output signal
KR830001580B1 (en) Voiceless two-wire simultaneous call device for a loudspeaker
KR870001636B1 (en) Noise silence circuit of a automatic gain regulator
JPH0456450A (en) Amplifier circuit
RU2037970C1 (en) Acoustic-electric transducer
JPH0419869Y2 (en)
KR920013892A (en) Signal amplification circuit
KR840003841A (en) Supply circuit for eddy current probe

Legal Events

Date Code Title Description
A201 Request for examination
G160 Decision to publish patent application
E701 Decision to grant or registration of patent right
GRNT Written decision to grant
FPAY Annual fee payment

Payment date: 20020723

Year of fee payment: 12

LAPS Lapse due to unpaid annual fee