The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 09, 2001
Filed:
Jan. 22, 1999
Barry K. Kates, Austin, TX (US);
John Cummings, Round Rock, TX (US);
Dell USA, L.P., Round Rock, TX (US);
Abstract
A switching flyback regulator circuit for providing a plurality of regulated DC voltage power supplies. The flyback regulator circuit includes a primary inductive element coupled in series with a first switch to turn charging current flow through the primary inductive element ON and OFF. A first secondary inductive element having a first end coupled to supply a first power source. A second secondary inductive element has a first end coupled to produce the second power source, and a second end coupled to a second switch to turn current flow through the second secondary inductive element ON and OFF. The first secondary inductive element and the second secondary inductive element are magnetically coupled to the primary inductive element. A control circuit generates a ramped voltage signal having a negative slope to control the ON and OFF duty cycle of the second switch such that when the first switch is operated to allow the primary inductive element to discharge, current flows through the first secondary inductive element before current flows in the other secondary inductive element. The current through the second switch is zero when the second switch is turned OFF and ON, thereby eliminating switching losses and improving efficiency of the flyback regulator circuit.