JPS5627557A - Side-tone preventing circuit - Google Patents

Side-tone preventing circuit

Info

Publication number
JPS5627557A
JPS5627557A JP10220979A JP10220979A JPS5627557A JP S5627557 A JPS5627557 A JP S5627557A JP 10220979 A JP10220979 A JP 10220979A JP 10220979 A JP10220979 A JP 10220979A JP S5627557 A JPS5627557 A JP S5627557A
Authority
JP
Japan
Prior art keywords
damped
tone
signal
voltage
constant rate
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
JP10220979A
Other languages
Japanese (ja)
Other versions
JPS60823B2 (en
Inventor
Hiroshi Kito
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co 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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP10220979A priority Critical patent/JPS60823B2/en
Publication of JPS5627557A publication Critical patent/JPS5627557A/en
Publication of JPS60823B2 publication Critical patent/JPS60823B2/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/58—Anti-side-tone circuits
    • H04M1/585—Anti-side-tone circuits implemented without inductive element

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Interconnected Communication Systems, Intercoms, And Interphones (AREA)

Abstract

PURPOSE:To obtain the side-tone preventive effect by applying the damped voltage of an input signal between the base and emitter of an amplifying transistor during a call and by reducing its error voltage. CONSTITUTION:While an audio signal having electric power amplified is transmitted from terminal L1 and L2 to subordinate equipment 5 after passing through capacitor C3 and resistor R7, the emitter circuit of transistor TR1 is applied with a signal damped at a constant rate. The base circuit, on the other hand, is applied with a signal, damped at a constant rate from the output of amplifier 3 by way of resistors R6 and R5 and a voltage appearing at receiver R is extremely small, obtaining the side-tone preventive effect.
JP10220979A 1979-08-13 1979-08-13 Sidetone prevention circuit Expired JPS60823B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10220979A JPS60823B2 (en) 1979-08-13 1979-08-13 Sidetone prevention circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10220979A JPS60823B2 (en) 1979-08-13 1979-08-13 Sidetone prevention circuit

Publications (2)

Publication Number Publication Date
JPS5627557A true JPS5627557A (en) 1981-03-17
JPS60823B2 JPS60823B2 (en) 1985-01-10

Family

ID=14321264

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10220979A Expired JPS60823B2 (en) 1979-08-13 1979-08-13 Sidetone prevention circuit

Country Status (1)

Country Link
JP (1) JPS60823B2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6353168A (en) * 1986-08-21 1988-03-07 Toyoda Gosei Co Ltd Steering wheel
JP6981915B2 (en) 2018-04-19 2021-12-17 富士フイルム株式会社 Endoscope optical system and endoscope

Also Published As

Publication number Publication date
JPS60823B2 (en) 1985-01-10

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