| 摘要 |
<p>An AC to DC converter includes a power factor pre-regulating circuit for conditioning input AC current. A DC to DC converter circuit is cascaded to the power factor pre-regulating circuit for supplying an output DC voltage to a load. A first soft switching phase arm defining a zero voltage switching pole is shared by the power factor pre-regulating circuit and the DC to DC converter circuit. A second soft switching phase arm defining a zero current switching pole forms part of the DC to DC converter circuit. A transformer is coupled between first and second switch nodes in the respective first and second phase arms, and a controller is provided for operating the first and second phase arms for switching the control signals. The invention extends to a method of operating an AC to DC converter using first and second control signals having substantially the same duty cycle, and altering the phase between the first and second control signals so as to control the output power to the load.</p> |
