| 摘要 |
PROBLEM TO BE SOLVED: To reduce a switching loss in the wide conductive ratio of a main switch element and realise a lower cost. SOLUTION: A step-down Buck type converter comprises a DC power supply Vin, a main switch element Qx, a main coil Lx connected in series, a flywheel diode Dx, and a smoothing capacitor Cx. An auxiliary coil Lw, a resonance capacitor Cw, and an auxiliary switch element Qw are provided. The auxiliary switch element Qw and the resonance capacitor Cw constitute a serial circuit; and the serial circuit, the auxiliary coil Lw, and the DC power supply Vin form a serial closed loop. The serial circuit, the main switch element Qx, and the flywheel diode Dx form a serial closed loop. The main switch element Qx and the auxiliary switch element Qw turn on alternately, with the main switch element Qx being so controlled that it turns on within a prescribed timeτzz after the auxiliary switch element Qw turns off. COPYRIGHT: (C)2005,JPO&NCIPI |
