Parallel-mode extended-period quasiresonant convertor

Ka Wai Eric Cheng, P. D. Evans

Research output: Journal article publicationJournal articleAcademic researchpeer-review

43 Citations (Scopus)


A new circuit, a parallel-mode, extended-period, zero-current quasiresonant convertor (PM-EP-ZCQRC), is introduced. It has low switching losses, because the switching conditions are those of a quasiresonant convertor, but it operates at constant frequency by using the dutyratio technique of conventional switched-mode power supplies for output regulation. The modes of operation of the circuit are described and analysed. The results of open-loop tests on a prototype circuit are presented and are shown to agree with predictions. The efficiency of the circuit was found to be 80 to 90% and a comparison of loss components with those in a quasiresonant convertor (QRC) is given.
Original languageEnglish
Pages (from-to)243-251
Number of pages9
JournalIEE Proceedings B: Electric Power Applications
Issue number5
Publication statusPublished - 1 Jan 1991
Externally publishedYes


  • Convertors
  • Power electronics
  • Resonant convertors
  • Switched-mode power supplies

ASJC Scopus subject areas

  • General Engineering


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