Abstract: A voltage transformer comprises a multi-limb transformer core having a central limb, a first outer limb, and a second outer limb. The voltage transformer also comprises a first primary winding wound about the central limb, a second primary winding wound about the central limb, a first secondary winding wound about the central limb, and a second secondary winding wound about the central limb. A first balance winding is wound about the first outer limb and coupled in series with the first primary winding, and a second balance winding is wound about the second outer limb and coupled in series with the second primary winding. The first and second balance windings are coupleable together via mutual inductance in response to first and second currents flowing therethrough.

Abstract: A switched mode power supply includes a multilevel buck power converter and a control circuit. The power converter includes a first buck circuit and a second buck circuit each having a power switch, a rectifier, and an inductor. The power supply may further include a resonant power converter coupled to the multilevel buck power converter. In some examples, the control circuit is configured to generate control signals for the first buck circuit's power switch and the second buck circuit's power switch to control the power converter, and adjust a switching frequency of the control signals to control the amount of reverse current flowing in the first buck circuit and the second buck circuit to achieve zero voltage switching of the first buck circuit's power switch and the second buck circuit's power switch. Other example multilevel buck power converters and power supplies are also disclosed.

Abstract: A power conversion apparatus comprises a main transformer having first and second windings wound about a core and coupled together via mutual inductance. First and second voltage converters are coupled to a first and second input voltage sources and configured to supply first and second currents simultaneously to the first and second windings. The power conversion apparatus also comprises a secondary transformer having a first winding configured to generate a first magnetic flux in a first direction in response to the first current flowing therethrough and having a second winding configured to generate a second magnetic flux in a second direction opposite the first direction in response to the second current flowing therethrough. The first and second windings of the secondary transformer are coupled together via mutual inductance in response to the first and second currents flowing therethrough.

Abstract: A power conversion apparatus comprises a main transformer having first and second windings wound about a core and coupled together via mutual inductance. First and second voltage converters are coupled to a first and second input voltage sources and configured to supply first and second currents simultaneously to the first and second windings. The power conversion apparatus also comprises a secondary transformer having a first winding configured to generate a first magnetic flux in a first direction in response to the first current flowing therethrough and having a second winding configured to generate a second magnetic flux in a second direction opposite the first direction in response to the second current flowing therethrough. The first and second windings of the secondary transformer are coupled together via mutual inductance in response to the first and second currents flowing therethrough.

Abstract: A switched mode power supply includes a multilevel buck power converter and a control circuit. The power converter includes a first buck circuit and a second buck circuit each having a power switch, a rectifier, and an inductor. The power supply may further include a resonant power converter coupled to the multilevel buck power converter. In some examples, the control circuit is configured to generate control signals for the first buck circuit's power switch and the second buck circuit's power switch to control the power converter, and adjust a switching frequency of the control signals to control the amount of reverse current flowing in the first buck circuit and the second buck circuit to achieve zero voltage switching of the first buck circuit's power switch and the second buck circuit's power switch. Other example multilevel buck power converters and power supplies are also disclosed.