| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a high frequency power transformer wherein a primary winding having no center tap and at least a pair of secondary windings having center taps for outputting full-wave rectified current are arranged on a nanocrystal soft magnetic alloy thin belt magnetic core, and a power converter of high efficiency and reliability which uses the high frequency power transformer. SOLUTION: In a no-cut nanocrystal soft magnetic alloy thin belt magnetic core, Fe wherein peak value of magnetizing force is 0.05 A/m and permeability at a frequency of 20 kHz is larger than 30,000 and at most 80,000 is selected as the main component, and fine crystal grains whose crystal grain diameter is at most 50 nm occupies at least 50% of a total volume of the texture. In a high frequency power transformer, a primary winding having no center tap and at least a pair of secondary windings for outputting full-wave rectified current are arranged on the nanocrystal soft magnetic alloy thin belt magnetic core. Two coupling coefficients at 20 kHz of the primary winding and the respective secondary windings which are main outputs of the primary winding are at least 0.9999. A value that a larger leakage inductance which is measured from the primary winding by short-circutting the respective secondary windings as the main outputs is divided by a smaller leakage inductance is at most 1.1.</p> |
