Chang Sung Corp recently announced the launch of their new LK series cores (Ellipse cores made out of Mega Flux Material). The improvement in the block material consists of a 7.5 radius edge creating an Ellipse core. This elliptical core design results in a wider window area. In addition the new LK series cores offer better DC Bias characteristics than standard Mega Flux block cores (square blocks), thus LK series cores are the optimum alternative when design engineers are looking for a most economical alternative than “High Flux” cores and at the same time they expect to obtain improved DC Bias performance compared to standard Mega Flux block cores.
Mega Flux Ellipsoidal cores advantages.
The advantages of ellipse core made out of Mega Flux material are:
1.) More effective winding (less copper usage);
2.) Wider window area than regular blocks and cylinder cores
For better illustration, please refer to the below comparison matrix among Std Block core, Cylinder core and Ellipse Core.
3.)
![]() Block Core |
![]() Cylinder Core |
![]() Ellipse Core |
|
|---|---|---|---|
|
Cross Sectional Area (cm2)
|
3.0 x 1.5 = 4.5
|
OD 2.4 = 4.5
|
3.3 x 1.5 = 4.5
|
|
Wire Length per turn (cm)
|
9
|
7.53
|
8.31
|
|
Reference
|
Longer wire length for 1 turn
|
Smaller Window Area
|
wider Wa than block and cylinder cores wire length 8% shorter than block core |
4.) Improved DC Bias Performance
Improved DC Bias performance allowing the reduction of copper usage resulting in lower losses compared to standard Mega Flux block cores.
The usual powder materials used in block cores is Mega Flux, a powder form of Iron and Silicon, and High Flux, a powder form of Iron and Nickel. There are advantages and disadvantages between the Mega Flux and High Flux. The Ellipse core makes a successful compromise between the two materials.
| MegaFlux | High Flux | Ellipse | |
|---|---|---|---|
|
DC Bias
|
++
|
+
|
+++
|
|
Core Loss
|
+
|
+++
|
++
|
|
Cost
|
++
|
+
|
+++
|
From the graph 1 below you can see the LK (Ellipse Mega Flux) shows higher DCB (DC Bias) over most of the scale. This gives the advantage to the Ellipse core.

From the Table below, you can also see that the Ellipse core has advantages over the Block core.
|
Core Loss Units (mW/cc)
|
Material Perm 60u Core Loss | |
|---|---|---|
| @25KHz, 500 Gauss | @ 25KHz, 1KG | |
|
BH ( High Flux Block Core)
|
25
|
137
|
|
LK (MegaFlux Ellipse Core)
|
48
|
218
|
|
BK (MegaFlux Block Core)
|
64
|
257
|
Product Range
Ellipse cores (LK series) are available in 60x35mm and 70×35 mm. Posts are available in 35x15mm and 35x15mm. All ellipse cores are available in 26, 40 and 60 Mega Flux material.
See More: Available LK Cores Specifications and Dimensions
Applications
Ellipse cores are meant to be used mainly in high current applications thus making them suitable for use in Solar power applications, UPS inverters and reactors used in Electrical vehicles, including charges.
Conclusion:
Design engineer will find LK Ellipse core to be a viable alternative (economic wise) in many high current applications versus High Flux and standard Mega Flux block cores, thus they can expect low cost and improved DC Bias performance at the same time.






