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:
Sep. 03, 2002
Filed:
Aug. 09, 2001
Tomoyasu Yamada, Niiza, JP;
Sanken Electric Co., Ltd., , JP;
Abstract
A serial circuit of the primary winding ( ) of a transformer ( ), a switching device ( ) and a current-detecting resistor ( ) is connected between a pair of dc terminals ( ). A smoothing capacitor ( ) is connected to the secondary winding ( ) of the transformer ( ) via a diode ( ). A resonance capacitor ( ) is connected in parallel with the serial circuit of the switching device ( ) and the current-detecting resistor ( ). The current detection signal, the output voltage detection signal, and the switch voltage detection signal are combined to provide control pulses for the switching device ( ). A control circuit ( ) includes a minimum non-conducting period determination circuit for setting a first and a second minimum nonconducting period with hysteresis. The nonconducting periods of the switching device are placed under the limitation of the minimum nonconducting periods when the load is light. The zero-voltage switching of the switching device ( ) is effected upon lapse of the minimum non-conducting periods and upon completion of the release of the stored energy from the transformer ( ).