Patent ID: 7012381
Filing Date: 2006-03-14
Classification: H02M,H05B,Y02B

Abstract:
1. A DC-DC converter of the voltage reduction-buck type comprising: a direct current source (Vin); an ON-OFF-controllable main switching device (Qx); a main coil (Lx) which is series connected to the main switching device (Qx); a fly-wheel diode (Dx) which is arranged such that the induction current of the main coil (Lx) flows when the main switching device (Qx) is shifted into the OFF state; a smoothing capacitor (Cx) for smoothing the output of the main coil (Lx); and an auxiliary transformer (Tw) with a primary winding (Pw) and a secondary winding (Sw), wherein the primary winding (Pw), the direct current source (Vin), the main switching device (Qx) and the fly-wheel diode (Dx) are connected in series, and the secondary winding (Sw), a resonant capacitor (Cw) and an ON-OFF-controllable auxiliary switching device (Qw) form a series-connected closed loop, wherein the main switching device (Qx) and the auxiliary switching device (Qw) are controlled such that they are alternatively shifted into the ON state, and wherein the main switching device (Qx) is shifted into the ON state within a given time after the auxiliary switching device (Qw) has been shifted into the OFF state.