Patent ID: 6169675
Filing Date: 2001-01-02
Classification: H02M,Y02B

Abstract:
A synchronous rectifying type DC-DC converter circuit comprising: a plurality of DC-DC converters connected in parallel for supplying a predetermined direct current to a load, and for preventing said current from entering one or more of said converters, each of said converters comprising: a rectifying switch connected in series with a secondary winding of a transformer; a fly wheel switch connected in parallel with said secondary winding of said transformer; and an auxiliary winding induced by a voltage generated on a primary winding of said transformer, and providing an output having polarities opposite to each other to a control terminal of the rectifying switch and to a control terminal of the fly wheel switch; and a drive keeping circuit for keeping an ON-status of said fly wheel switch during a period for which said transformer is magnetically reset, wherein each of said DC-DC converters turns OFF said fly wheel switch when the output value to said load is smaller than the threshold.