Patent Yard Sign in
Expired European patentEurope

Constant current drive for switching power supply

EP 0142980 B1 · Applicant: TANDEM COMPUTERS INCORPORATED

EPO PDF

Overview

The published document from the EPO: abstract, claims, description and drawings. Open it full size

Read the whole patent

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.

Google PatentsEPO PDF

Why it's free to use

  • Filed November 14, 1984 and granted March 1, 1989. A European patent lasts at most 20 years from filing, so its term ended November 14, 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 May 14, 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.
FiledNovember 14, 1984
PublishedMay 29, 1985
GrantedMarch 1, 1989
Term endedNovember 14, 2004
Application numberEP 84307872
Classification (CPC)H02M1/08 +1 more

Timeline

Timeline From EPO dates

1985198719891991199319951997199920012003Application filedNov 14, 1984PublishedMay 29, 1985Patent grantedMarch 1, 1989Term endedNov 14, 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.