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Expired European patentEurope

Improvements in or relating to rectifier circuits

EP 0157789 B1 · Applicant: AT&T Corp.

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Overview

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Listed from its EPO record in Patent Yard's archive of European patents past their term. Its claims, description and drawings are in the EPO PDF and on Google Patents, and the Claude kit works from them.

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Why it's free to use

  • Filed August 20, 1984 and granted January 13, 1988. A European patent lasts at most 20 years from filing, so its term ended August 20, 2004.
  • A supplementary protection certificate, which can extend a medicine or crop-protection patent, adds at most five and a half years, so even that would have ended by February 20, 2010.
  • We check European rights only. A US or other national patent in its family could still be in force: check its family on Espacenet or Google Patents.
FiledAugust 20, 1984
PublishedOctober 16, 1985
GrantedJanuary 13, 1988
Term endedAugust 20, 2004
Application numberEP 84903155
Classification (CPC)G01R19/02 +1 more

Timeline

Timeline From EPO dates

1985198719891991199319951997199920012003Application filedAug 20, 1984PublishedOct 16, 1985Patent grantedJan 13, 1988Term endedAug 20, 2004

Sources & verification

Official EPO records

Full published documentClaims, description and drawings as a PDF.EPOEuropean Patent RegisterProcedure, status, file inspection and legal events.EPOLinked open EP data recordThe bibliographic record this page is built from.EPO

Cross-check elsewhere

Google PatentsFull text, worldwide family, citing patents and legal events.patents.google.comEspacenetNational family members and their legal status.European Patent Office

Everything on this page comes from the EPO record linked above. EPO data used under CC BY 4.0.