A power supply control system for a power supply having a first half-bridge leg and a second half-bridge leg. In the control system, a first plurality of drive signals are configured to operate a half-bridge as a forward leg while a second plurality of drive signals are configured to operate a half-bridge as a backward leg. A switch element is intermediate the first and second plurality of drive signals and the first and the second half-bridge legs, the switch element being adapted to operate the first half-bridge as a forward leg and the second half-bridge as a backward leg in a first operating mode, the switch element being further adapted to operate the first half-bridge as a backward leg and the second half-bridge as a forward leg in a second operating mode.

A power supply control system for a power supply having a first half-bridge leg and a second half-bridge leg. In the control system, a first plurality of drive signals are configured to operate a half-bridge as a forward leg while a second plurality of drive signals are configured to operate a half-bridge as a backward leg. A switch element is intermediate the first and second plurality of drive signals and the first and the second half-bridge legs, the switch element being adapted to operate the first half-bridge as a forward leg and the second half-bridge as a backward leg in a first operating mode, the switch element being further adapted to operate the first half-bridge as a backward leg and the second half-bridge as a forward leg in a second operating mode.

To form a center tap (CT), at least two coils must be formed. This increases the number of steps in the winding process and decreases the workability. To prevent this, a conductor having a plurality of plate portions that are connected to each other at one vertex of a rectangular shape is formed. The conductor is wound on a winding shaft, thus forming two coils.

Optimal operating techniques are disclosed for using coreless printed-circuit-board (PCB) transformers under (1) minimum input power conditions and (2) maximum energy efficiency conditions. The coreless PCB transformers should be operated at or near the 'maximum impedance frequency' (MIF) in order to reduce input power requirement. For maximum energy efficiency, the transformers should be at or near the "maximum efficiency frequency" (MEF) which is below the MIF. The operating principle has been confirmed by measurement and simulation. The proposed operating techniques can be applied to coreless PCB transformers in many circuits that have to meet stringent height requirements, for example to isolate the gates of power MOSFET and IGBT devices from the input power supply.

A high-frequency transformer, comprises: a ring core made of amorphous magnetic material; a core protection box made of conductive material and enclosing the ring core; and a high-voltage winding, consisting of enamel-insulated wire wound on the core protection box. Wherein, on the ring top wall of the core protection box there is a ring gap in the peripheral direction, and at inner fringe and outer fringe of the ring gap, a plurality of leading wires are respectively arranged in the peripheral direction. The leading wires at inner fringe and outer fringe of the ring gap are electrically-connected together respectively and form two terminals. The core protection box and the two terminals constitute low-voltage winding of the high-frequency transformer. If the low-voltage winding comprises two or more core protection boxes, it can have a central tap or have multi-turn. A thus fabricated high-frequency transformer has a smaller size, a lighter weight and is more apt to industrial batch manufacture. Further, the magnetic coupling between the high-voltage winding and the low-voltage winding can be increased.

Embodiments of the invention include a transformer device (10) having a saturation region for limiting ingress noise and other noise. The transformer comprises a magnetic core (28), an input coil (32) and an output coil (34) arranged so that the output signal caused by the magnetic linkage between the input and output coils through the magnetic core is based on the magnitude of the input signal. According to an embodiment of the invention, the magnetic core includes a saturation region (42) that limits the output signal regardless of the magnitude of the input signal once the saturation region reaches its saturation magnetization state. The saturation region comprises a reduced saturation magnetization level caused by a geometrically constricted region of the magnetic core or, alternatively, by a modified, magnetic-equivalent region having properties similar to a geometrically constricted region.

A magnetic or electromagnetic circuit component includes an embedded magnetic material (e.g., ferromagnetic) in an HDI structure with alternating dielectric and metal or winding layers. In one embodiment, the ferromagnetic material is situated in a substrate well, or cavity, with or without an adhesive. Alternatively, the ferromagnetic material is co-fired with the ceramic substrate and then machined to achieve a required core shape. An electroplating process is employed to construct the metal layers, such process including differential plating for varying the thickness of metal layers and/or other portions of the circuit. Laser ablation or any other suitable technique is employed to make through-holes for insertion of the posts of a ferromagnetic core plate used to complete a magnetic circuit, if required. Advantageously, a magnetic or electromagnetic component may have a height of less than about 0.1 inch. Furthermore, such magnetic or electromagnetic circuit components allow for very low inductance interconnections between these components and other circuit elements. Moreover, in a power supply, for example, not only can the complete power supply be built using HDI technology, but power density is increased at relatively low cost and at a high level of reproducibility.