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:
Nov. 19, 2002
Filed:
Feb. 01, 2001
Cornelis Johannes Adrianus Schetters, Eindhoven, NL;
Johannus Emmanuel Maria Lammers, Eindhoven, NL;
Tijmen Cornelis Van Bodegraven, Eindhoven, NL;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
DC/DC conversion circuit ( ), includes a transformer ( ) having a primary winding ( ), a secondary winding ( ), and an auxiliary winding ( ); a switching transistor (T), including a series circuit with the primary winding ( ) between first and second direct current input terminals ( ); a start circuit (R , C ) connected to a control electrode of the switching transistor (T) for switching the switching transistor (T) on by powering the direct current input terminals ( ); a control transistor connected to the control electrode of the switching transistor (T) for switching off the switching transistor (T) in dependence on a current flowing through the series circuit during operation. The auxiliary winding ( ) and the control transistor (Q) connect to a voltage control circuit ( ) for setting an output power provided at the secondary winding ( ) of the transformer ( ) during operation by a controlled switching-on of the switching transistor (T) in dependence on the magnitude of a current flowing in the primary winding ( ). The conversion circuit ( ) is arranged such that during operation via the auxiliary winding ( ) a voltage required at the control electrode of the switching transistor (T) for on thereof is built up in a time period which is inversely proportional to the amount of output power provided at the secondary winding ( ).