GB2017437A - Overload protection circuit for video amplifiers - Google Patents

Overload protection circuit for video amplifiers

Info

Publication number
GB2017437A
GB2017437A GB7904854A GB7904854A GB2017437A GB 2017437 A GB2017437 A GB 2017437A GB 7904854 A GB7904854 A GB 7904854A GB 7904854 A GB7904854 A GB 7904854A GB 2017437 A GB2017437 A GB 2017437A
Authority
GB
United Kingdom
Prior art keywords
transistor
switch
protection circuit
high frequency
signal transfer
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
GB7904854A
Other versions
GB2017437B (en
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.)
RCA Corp
Original Assignee
RCA Corp
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
Priority claimed from US05/960,930 external-priority patent/US4197558A/en
Application filed by RCA Corp filed Critical RCA Corp
Publication of GB2017437A publication Critical patent/GB2017437A/en
Application granted granted Critical
Publication of GB2017437B publication Critical patent/GB2017437B/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/52—Circuit arrangements for protecting such amplifiers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/14—Picture signal circuitry for video frequency region
    • H04N5/148—Video amplifiers

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Picture Signal Circuits (AREA)
  • Amplifiers (AREA)
  • Television Receiver Circuits (AREA)
  • Processing Of Color Television Signals (AREA)
  • Protection Of Static Devices (AREA)

Abstract

To avoid excessive dissipation in a video output stage, particularly in Class B or C operation, signal transfer of higher frequencies, e.g. noise, is selectively attenuated. Accordingly transferred signals, e.g. en route to the output stage, are sampled 17, 15, differentiated 53, clamped 56, rectified 55 and then integrated 57 to switch on a normally off transistor 52 whenever high frequency signals are incident. Since the integrator 57 has a bleeder shunt 58, only high density high frequency signals will switch on the alarm transistor 52. If these occur, the video signal transfer is progressively reduced, e.g. by conditioning the output 62 of the luminance contrast control 60, whereof a resistance 65 may pass the collector current of the alarm transistor 52. <IMAGE>
GB7904854A 1978-02-16 1979-02-12 Overload protection circuit for video amplifiers Expired GB2017437B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB626078 1978-02-16
US05/960,930 US4197558A (en) 1978-02-16 1978-11-15 Overload protection circuit for video amplifiers

Publications (2)

Publication Number Publication Date
GB2017437A true GB2017437A (en) 1979-10-03
GB2017437B GB2017437B (en) 1982-06-30

Family

ID=26240560

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7904854A Expired GB2017437B (en) 1978-02-16 1979-02-12 Overload protection circuit for video amplifiers

Country Status (15)

Country Link
JP (1) JPS54129855A (en)
AU (1) AU531219B2 (en)
BE (1) BE874250A (en)
CA (1) CA1112756A (en)
DE (1) DE2906010C3 (en)
DK (1) DK147475B (en)
ES (1) ES477796A1 (en)
FI (1) FI790441A (en)
FR (1) FR2417904A1 (en)
GB (1) GB2017437B (en)
IT (1) IT1111128B (en)
NO (1) NO790503L (en)
NZ (1) NZ189661A (en)
PL (1) PL122976B1 (en)
SE (1) SE430289B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998038734A2 (en) * 1997-02-27 1998-09-03 Koninklijke Philips Electronics N.V. Amplifier arrangement
US5994958A (en) * 1997-02-27 1999-11-30 U.S. Philips Corporation Amplifier arrangement

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1215248B (en) * 1985-03-13 1990-01-31 Ates Componenti Elettron ELECTRONIC VOLTAGE REGULATION DEVICE WITH THERMAL DISSIPATION COMPENSATION, IN PARTICULAR FOR ALTERNATORS.

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3637923A (en) * 1970-10-30 1972-01-25 Zenith Radio Corp Automatic brightness limiter
US3984631A (en) * 1975-02-24 1976-10-05 Warwick Electronics Inc. Automatic peaking control circuit for low level T.V. signal reception
JPS56698Y2 (en) * 1976-01-09 1981-01-09

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998038734A2 (en) * 1997-02-27 1998-09-03 Koninklijke Philips Electronics N.V. Amplifier arrangement
US5994958A (en) * 1997-02-27 1999-11-30 U.S. Philips Corporation Amplifier arrangement
WO1998038734A3 (en) * 1998-02-16 1998-12-03 Koninkl Philips Electronics Nv Amplifier arrangement

Also Published As

Publication number Publication date
DE2906010B2 (en) 1981-06-04
NO790503L (en) 1979-08-17
CA1112756A (en) 1981-11-17
DK65679A (en) 1979-08-17
BE874250A (en) 1979-06-18
SE7901135L (en) 1979-08-17
PL213478A1 (en) 1979-12-17
DE2906010C3 (en) 1982-02-11
NZ189661A (en) 1982-12-21
IT7920197A0 (en) 1979-02-14
AU531219B2 (en) 1983-08-18
PL122976B1 (en) 1982-09-30
DK147475B (en) 1984-08-20
GB2017437B (en) 1982-06-30
FI790441A (en) 1979-08-17
DE2906010A1 (en) 1979-08-30
ES477796A1 (en) 1979-10-16
JPS54129855A (en) 1979-10-08
AU4393279A (en) 1979-08-23
SE430289B (en) 1983-10-31
FR2417904A1 (en) 1979-09-14
IT1111128B (en) 1986-01-13

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee