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US 5,184,103 AGranted
High coupling transformer adapted to a chopping supply circuit
AssigneeBull SAS
InventorsJean Gadreau, Andre Pascal
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AssigneeBull SAS
InventorsJean Gadreau, Andre Pascal
Estimating the term…
Turns of primary and secondary windings of a chopper power supply transformer are formed by magnetically coupled stacked parallel planar printed circuit conducting layers. The primary winding is between first and second parts of the secondary winding that are connected in series and parallel. Layers at opposite ends of the primary winding are (i) arranged to reduce leakage currents between the secondary winding parts and (ii) positioned between further layers of the primary winding and the secondary winding. Terminals of the first and second layers are connected together as a first input terminal of the transformer. Other terminals of the first and second layers have a common connection. Further layers of the primary winding are connected in series with each other between the common connection and a second input terminal of the transformer. A primary winding shield turn, positioned between a turn of the secondary winding in closest proximity thereto and all other turns of the primary winding, includes an exterior segment for conducting current supplied to the transformer between terminals of the layer forming the shield turn and an interior conducting portion directly connected to the exterior portion. The interior and exterior portions have approximately the same DC potential. A direct connection subsists between the interior portion and one terminal of the shield turn layer. The interior portion is proximate a magnetic core and forms an electrostatic shield for currents having a tendency to flow between the windings.
A transformer adapted to be connected in a chopper power supply driven by a DC source having a terminal, the supply including a switching transistor having an electrode, the transformer comprising a primary winding and a secondary winding having first and second parts on opposite sides of the primary winding, each part of said secondary winding having turns connected in series and parallel, each of said windings including plural turns, individual ones of said turns being formed by a printed circuit electrically conducting layer, said layers being (i) magnetically coupled to each other, (ii) stacked in mutually parallel planes, and (iii) connected to each other so that:
A transformer comprising a primary winding, and a secondary winding including first and second similar spaced parts, each of said windings including plural turns, individual ones of said turns being formed by a printed circuit electrically conducting layer, said layers being (i) magnetically coupled to each other and (ii) stacked in mutually parallel planes so that the layers of the primary winding are between the layers of the first and second parts of the secondary winding each part of said secondary winding having turns connected in series and parallel, first and second of said layers at opposite ends of the primary winding being connected and configured to reduce leakage currents between the spaced parts of the secondary winding relative to the leakage current that would flow between the spaced parts of the secondary winding without said first and second layers being present and being positioned between further layers of the primary winding and the layers of the secondary winding, one terminal of said first and second layers being connected together as a first input terminal of the transformer, a second terminal of said first and second layers having a common connection, further layers of the primary winding being connected in series with each other between the common connection of the second terminals and a second input terminal of the transformer.
The transformer of 16 wherein each of the first and second layers at opposite ends of the primary winding includes:
A transformer comprising a primary winding and a secondary winding including first and second similar spaced parts, between which the primary winding is located, each of said windings including plural turns, the turns of each secondary winding part being connected in series and parallel, individual ones of said turns being formed by a printed circuit electrically conducting layer, said layers being (i) magnetically coupled to each other and (ii) stacked in mutually parallel planes, the primary winding including a shield turn positioned between a turn of the secondary winding in closest proximity thereto and all other turns of the primary winding, the shield turn including an exterior segment for conducting current supplied to the transformer between terminals of said layer forming the shield turn and an interior electrically conducting portion directly connected to the exterior portion so the interior and exterior portions are at approximately the same DC potential, the interior portion being arranged so that there is a direct connection between it and one of said terminals of the layer forming the shield turn, the interior portion being in close proximity to the magnetic core means and providing an electrostatic shield for currents having a tendency to flow between the windings.
Dependencies are inferred from the claim text.