Patent ID: 8138744
Filing Date: 2012-03-20
Classification: H01F,H02M

Abstract:
1. A voltage buck/boost circuit comprising: a combined type transformer comprising: a transformer core; an inductor core; and first and second coils each wound around said transformer core and also said inductor core and each generating magnetic flux when energized, said first and second coils being each connected at one end thereof to a positive-pole terminal of a first terminal; wherein the transformer core and said first and second coils form a transformer, and said inductor core and said first and second coils form an inductor, wherein said first coil and said second coil are connected with each other and wound in opposite winding directions so that a direction of the magnetic flux generated from said first coil is opposite to a direction of the magnetic flux generated from said second coil, and wherein said first and second coils each have a plurality of first winding portions contributing to a function of the transformer and generating magnetic flux passing through the transformer core, and a plurality of second winding portions contributing to a function of the inductor and generating magnetic flux passing through the inductor core, the first winding portions and the second winding portions being disposed alternatively with each other; a first switching element connected at one end thereof to another end of the first coil and connected at another end thereof to a common reference terminal; a second switching element connected at one end thereof to the other end of said first coil and connected at another end thereof to a positive-pole terminal of a second terminal; a third switching element connected at one end thereof to another end of the second coil and connected at another end thereof to the common reference terminal; and a fourth switching element connected at one end thereof to the other end of said second coil and connected at another end thereof to the positive-pole terminal of said second terminal.