Electrical transformer

An electrical transformer having primary winding segments and secondary winding segments interconnected, respectively, by first and second multilevel printed circuit boards disposed in a pair of overlaying planes and additional segments disposed perpendicular to the overlaying planes.

TECHNICAL FIELD

This invention relates to electrical transformers, and more particularly to compact electrical transformers.

BACKGROUND

As is known in the art, electrical transformers have a wide variety of applications. The transformer includes a primary winging and an adjacent secondary winding. Changes in electrical current passing through the primary winding induce a corresponding change in a magnetic field around the primary winding. This changing magnetic field induces a corresponding change in current in the adjacent, magnetically coupled secondary winding.

As is also known in the art, it is desirable to reduce the size of the transformer.

SUMMARY

In accordance with the present invention, an electrical transformer is provided having a first dielectric. The first dielectric includes a plurality of first electrically isolated electrical conductor segments. A second dielectric is disposed over, and in registration with, the first dielectric, such second dielectric having a plurality of second electrically isolated electrical conductor segments disposed on the second dielectric. The transformer includes a core having an aperture therein, such aperture extending between the first and second dielectrics. A plurality of third electrically isolated electrical conductor segments is provided. First ends of the third electrically isolated electrical conductor segments are electrically connected to the plurality of first electrically isolated electrical conductor segments and second ends of the third electrically isolated electrical conductor segments are electrically connected to the plurality of second electrically isolated electrical conductor segments to provide a portion of a primary winding and a portion of a secondary winding for the transformer. The primary winding comprises first ones of the first electrically isolated electrical conductor segments, first ones of the second electrically isolated electrical conductor segments, and first ones of the third electrically isolated electrical conductor segments. The secondary winding comprises second ones of the first electrically isolated electrical conductor segments, second ones of the second electrically isolated electrical conductor segments, and second ones of the third electrically isolated electrical conductor segments.

In one embodiment, the first and second dielectrics comprise multilevel printed circuit boards.

In one embodiment, the first and second multilevel printed circuit boards are disposed in a pair of overlaying planes and the plurality of third electrically isolated electrical conductor segments are disposed perpendicular to the overlaying planes.

In one embodiment, the primary and secondary winding provide loops around the core.

In one embodiment, the third electrically isolated electrical conductor segments are embedded within the core.

In one embodiment, the core comprises a toroidal shaped body and the dielectric body is disposed in a central region of the toroidal shaped body.

In accordance with another feature of the invention, an electrical transformer is provided having a first multilayer printed circuit board. The first multilevel printed circuit board includes a plurality of first electrically isolated electrical conductor segments disposed on each one of a plurality of electrically isolated levels of such first multilevel printed circuit board. A second multilayer printed circuit board is, disposed over, and in registration with, the first multilevel printed circuit board. The second multilevel printed circuit board has a plurality of second electrically isolated electrical conductor segments disposed on each one of a plurality of electrically isolated levels of such second multilevel printed circuit board. A pair of dielectric bodies is disposed between the first multilevel printed circuit board and the second multilevel printed circuit board. Each one of such bodies has disposed therein a plurality of third electrically isolated electrical conductor segments. First ends of the third electrically isolated electrical conductor segments are electrically connected to the plurality of first electrically isolated electrical conductor segments and second ends of the third electrically isolated electrical conductor segments are electrically connected to the plurality of second electrically isolated electrical conductor segments to provide a primary winding and a secondary winding for the transformer. The primary winding comprises a first ones of the first electrically isolated electrical conductor segments, first ones of the second electrically isolated electrical conductor segments, and first ones of the third electrically isolated electrical conductor segments. The secondary winding comprises second ones of the first electrically isolated electrical conductor segments, second ones of the second electrically isolated electrical conductor segments, and second ones of the third electrically isolated electrical conductor segments.

In accordance with another feature of the invention, an electrical transformer structure is provided. The structure includes a first multilayer printed circuit board having a plurality of first electrically isolated electrical conductor segments disposed on each one of a plurality of electrically isolated levels of such first multilevel printed circuit board. The structure includes a second multilayer printed circuit board, disposed over, and in registration with, the first multilevel printed circuit board. The second multilevel printed circuit board has a plurality of second electrically isolated electrical conductor segments disposed on each one of a plurality of electrically isolated levels of such second multilevel printed circuit board. A dielectric spacer member is disposed between the first multilevel printed circuit board and the second multilevel printed circuit board. The spacer member has a plurality of apertures therethrough. The apertures in the spacer member pass between a top and a bottom surface of the spacer member. A plurality of toroidal shaped cores is provided. Each one of such cores is disposed in a corresponding one of the plurality of apertures of the dielectric spacer member. Each one of the cores has an aperture therein, the apertures of the cores being coaxial with the apertures in the dielectric spacer member. A plurality of dielectric bodies is provided. Each one of such dielectric bodies is disposed in a corresponding one of the apertures in the cores. A plurality of plurality of dielectric bodies has a corresponding one of the sets of third electrically isolated electrical conductor segments. First ends of the third electrically isolated electrical conductor segments are electrically connected to the plurality of first electrically isolated electrical conductor segments and second ends of the third electrically isolated electrical conductor segments are electrically connected to the plurality of second electrically isolated electrical conductor segments to provide a primary winding and a secondary winding for the transformer. The primary winding comprises first ones of the first electrically isolated electrical conductor segments, first ones of the second electrically isolated electrical conductor segments, and first ones of the third electrically isolated electrical conductor segments. The secondary winding comprises second ones of the first electrically isolated electrical conductor segments, second ones of the second electrically isolated electrical conductor segments, and second ones of the third electrically isolated electrical conductor segments.

DETAILED DESCRIPTION

Referring now toFIG. 1, an electrical transformer10is shown having a core12, here, for example, a ferrite core, disposed between a pair of dielectrics14,16, here, for example, a pair of multilevel printed circuit boards14,16as shown. The first multilayer printed circuit board14has a plurality of first electrically isolated electrical conductor segments14a-14fdisposed on each one of a plurality of electrically isolated levels, or dielectric boards141and142of such first multilevel printed circuit board14. Thus, electrically isolated electrical conductor segments14a-14dare on different electrically isolated regions of dielectric board141of board14and electrically isolated electrical conductor segments14eand14fare on different electrically isolated regions of dielectric board142of board14.

The second multilayer printed circuit board16is disposed under, and is in registration with, the first multilevel printed circuit board14. The second multilevel printed circuit board has a plurality of second electrically isolated electrical conductor segments16a-16ddisposed on each one of a plurality of electrically isolated levels of such second multilevel printed circuit board16. Thus, electrically isolated electrical conductor segments16aand16bare on different electrically isolated regions of dielectric board161of board16, electrically isolated electrical conductor segment16cis on dielectric board162of board16, and electrical conductor segment16dis on dielectric board163of board16. Each one of the boards has electrically conductive plated through holes, one portion of the plated through holes being indicated by the numerical designation18and the other portion being indicated by the designation S2-S9and P2-P9.

It is noted that:

electrically conductive segment14ahas ends thereof connected between port P1and plated through hole P2;

electrically conductive segment14bhas ends thereof connected between plated through hole S9and port S10;

electrically conductive segment14chas ends thereof connected between plated through hole S2and port S1;

electrically conductive segment14dhas ends thereof connected between plated through hole P9and port P10;

electrically conductive segment14ehas ends thereof connected between plated through hole S5and plated through hole P5;

electrically conductive segment14fhas ends thereof connected between plated through hole P6and plated through hole P5;

electrically conductive segment16ahas ends thereof connected between plated through hole P3and plated through hole P4;

electrically conductive segment16bhas ends thereof connected between plated through hole P7and plated through hole P8;

electrically conductive segment16chas ends thereof connected between plated through hole S8and plated through hole S7; and

electrically conductive segment16dhas ends thereof connected between plated through hole S4and plated through hole S3.

The core12, shown more clearly inFIG. 2, has a plurality of apertures20a,20btherethrough. When assembled, the apertures20a,20bextends between the first and second multilevel printed circuits boards14,16, as shown inFIG. 1. Apair of dielectric bodies, here for example, printed circuit boards22a,22bare disposed in the apertures20a,20b, respectively as shown. Each one of the dielectric bodies22a,22bhas disposed therein a plurality of electrically isolated electrical conductor segments,24athrough24h, as shown. Thus, here body22ahas electrical conductor segments24a-24dthereon and body22bhas electrical conductor segments24e-24h, thereon, as shown.

The core12with the dielectric bodies22a,22bwith the electrical conductor segments24a-24hare inserted into a dielectric spacer30, as shown inFIGS. 1 and 3.

It is noted that the first and second multilevel printed circuit boards14,16are disposed in a pair of overlaying planes and the plurality of electrically isolated electrical conductor segments24a-24hare disposed perpendicular to the overlaying planes.

When assembled, first ends, here the upper ends inFIG. 1, of the electrically isolated electrical conductor segments24a-24hare electrically connected to the electrically isolated electrical conductor segments14a-14fand second ends, here the lower ends of the electrically isolated electrical conductor segments24a-24hare electrically connected to the electrically isolated electrical conductor segments16a-16hthrough the electrically plated through holes S2-S9and P2-P9. More particularly, when assembled:

the upper ends of electrical conductor segments24a-24hare electrically connected to plated through holes S9, P2, P6, S5, S6, P5, P9and S2, respectively; and

the lower ends of electrical conductor segments24a-24hare electrically connected to plated through holes S8, P3, P7, S4, S7, P4, P8and S3, respectively

With such connections, a primary winding of the transformer10comprises port P1, electrical conductor segments14a,24b,16a,24f,14f,24c,16b,24h,14dand port P10and a secondary winding comprises port S1, electrical conductor segments14c,24h,16d,24d,14e,24e,16d,24a,14band port S10.

It is noted that the primary and secondary winding provide loops around the portion12a(FIG. 3) of the core12. Further, it is noted that the electrically isolated electrical conductor segments24a-24hare embedded within the core12.

Referring now toFIG. 4, another embodiment is shown. Here, the transformer10′ has the pair of multilevel printed circuit boards,14and16, as described above in connection withFIGS. 1,2and3. Here, however, adjacent portions of a pair of toroidal shaped cores12a,12bprovide the core. The pair of toroidal shaped cores12a,12bare disposed within a pair of apertures provided through the dielectric spacer30′, as shown. A pair of circular shaped dielectric bodies22′a,22′bhaving the electrically conductive segments24a-24bare disposed within a corresponding one of the central, apertured, regions of the toroidal shaped bodies12a,12bas shown.

When assembled, first ends, here the upper ends inFIG. 4, of the electrically isolated electrical conductor segments24a-24hare electrically connected to the electrically isolated electrical conductor segments14a-14fand second ends, here the lower ends of the electrically isolated electrical conductor segments24a-24hare electrically connected to the electrically isolated electrical conductor segments16a-16hthrough the electrically plated through holes S2-S9and P2-P9. More particularly, when assembled:

the upper ends of electrical conductor segments24a-24hare electrically connected to plated through holes S9, P2, P6, S5, S6, P5, P9and S2, respectively; and

the lower ends of electrical conductor segments24a-24hare electrically connected to plated through holes S8, P3, P7, S4, S7, P4, P8and S3, respectively

With such connections, a primary winding of the transformer10comprises port P1, electrical conductor segments14a,24b,16a,24f,14f,24c,16b,24g,14dand port P10and a secondary winding comprises port S1, electrical conductor segments14c,24h,16d,24d,14e,24e,16d,24a,14band port S10.

Thus, here the primary and secondary winding provide loops around the portion12a(FIG. 3) of the adjacent portions12a′ and12b′ of the cores12aand12b. Further, it is noted that the electrically isolated electrical conductor segments24a-24hare embedded within the cores12aand12b, as shown. It is noted that segments24b,24c,24fand24gprovide the vertical portions of the primary loop and segments24h,24d,24eand24aprovide the vertical portions of the secondary loop.

It should be understood that the number of conductive segments through the dielectric bodies22a,22bor22a′,22b′ might be larger than the four segments shown with the number of conductive segments of the printed circuit boards being correspondingly increased. Thus, referring now toFIGS. 5 and 6, a modified exemplary one of the dielectric bodies22′aand22′b, here body22″ais shown. Here, the body22″ahas eight conductive segments24′S1-24′S4and24P1-24P4. The conductive segments24′S1-24′S4provide the vertical portions of the secondary loop and the conductive segments24′P1-24′P4provide the vertical portions of the primary loop. The eight conductive segments24′S1-24′S4and24P1-24P4have upper and lower conductive tabs38for making electrical connection to the plated through holes of the multilevel printed circuit boards14,16. Here, there is an electrically conductive shield40disposed between the segments24′S1-24′S4and the segments24P1-24P4. The electrically conductive shield40has tabs42for connection to a ground plane, not shown, of the multilevel printed circuit boards,14, and16and a vertical cutout that prevents the shield from introducing a shorted turn in the transformer. Here, the electrical conductor segments24′S1-24′S4and24P1-24P4and the shield40are copper and are embedded within an epoxy filler44.

As noted above, the body22″ais disposed within the central region of the toroidal shaped core12a.

Referring now toFIG. 7, an electrical transformer10″ is shown here with the upper multilayer printed circuit board14illustrated with only the electrical conductive segments used to interconnect transformer segments to be described in connection with FIG.8. Here, the dielectric spacer member30″ has a plurality of, here20, apertures therethrough. The apertures in the spacer member30″ pass between a top and a bottom surface of the spacer member. A plurality of toroidal shaped cores12″, as shown inFIG. 4is provided. Each one of such cores12″ is disposed in a corresponding one of the plurality of apertures of the dielectric spacer member30″. Each one of the cores12″ has an aperture therein, the apertures of the cores12″ being coaxial with the apertures in the dielectric spacer member30″. A plurality of dielectric bodies, here the body22″ as described above in connection withFIGS. 5 and 6is provided. Each one of such dielectric bodies22″ is disposed in a corresponding one of the apertures in the cores12″.

Thus, a plurality of plurality of dielectric bodies22″ has a corresponding one of the vertical electrically isolated electrical conductor segments24S1-24S4and24P1-24P4, as described above in connection withFIGS. 5 and 6. The ends or tabs38of the electrical conductor segments are electrically connected to electrically isolated electrical conductor segments of the upper and lower multilevel printed circuits boards. Here, however, the boards14,16are modified to provide not only primary and secondary windings, or loops around each one of the toroidal shaped cores, i.e., to provide a transformer segment10′, as shown inFIG. 8, but the conductor segments on the multilevel printed circuit boards are used to electrically interconnect each one of the transformer segments10′ as shown inFIG. 8, and thereby provide a larger transformer assembly10″.