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Expired Canadian patentCanada

Zero voltage switching buck derived converter

CA 2270816 C · Owner: Davidson, Christopher Donovan · Inventors: Davidson, Christopher Donovan

CIPO record

Overview

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A buck derived isolated DC-DC converter includes a half or full bridge of switching devices which are asymmetrically controlled so that top and bottom switches are opened and closed at mutually exclusive times. Primary side and secondary side DC blocking capacitor(s) and a small valued inductor are placed in series with an isolation transformer. A single secondary rectification non controlled switch and inductor-capacitor output filter are included. Additionally a voltage clamping circuit is added across the rectifier which includes an active switch which also may be connected to a tap on the output inductor.

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

Why it's free to use

  • Filed May 3, 1999 and granted December 23, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 3, 2019.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 3, 2021.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 3, 1999
GrantedDecember 23, 2003
Term endedMay 3, 2019
Patent numberCA 2270816 C
Classification (IPC)H02M3/33

Timeline

Timeline From CIPO dates

2000200220042006200820102012201420162018Application filedMay 3, 1999Patent grantedDec 23, 2003Term endedMay 3, 2019

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.