cupoftea
Advanced Member level 6

Hi,
Doing 4kW Full Bridge LLC converter resonant inductor of 24.9uH.
ETD59 with 1mm gap for AL=508.
(7 turns of 3 strands of TEX-ELZ 7/0.3mm)
100kHz.
Irms is 11.9A
Ipk is 17.2A. (+/-17.2A)
Bpk is 0.166T. Will the core losses be too excessive?
There are fans but not mounted right next to this inductor.
I can reduce the Bpk to 0.142T by using the 1.5mm gap ETD59 (AL = 381) and winding 8 turns.....but i thought the bigger gap will give more fringing flux problems?
On the same type of subject...
Hi,
We need ETD59 in N87 material ungapped.
However, ungapped is only available in 3C90
At 100kHz and 200mT, N87 is at 350kW/m^3, whereas 3C90 is at 450kW/m^3
That would mean the 3C90 ETD59 core dissipating 23W, but the N87 ETD59 dissipating 17.9W.
Would you say, with those dissipations, that even with a fan right on it, either 3C90 or N87 would go over the Curie temperature, and the transformer coils all go short circuit?
3C90
N87
Doing 4kW Full Bridge LLC converter resonant inductor of 24.9uH.
ETD59 with 1mm gap for AL=508.
(7 turns of 3 strands of TEX-ELZ 7/0.3mm)
100kHz.
Irms is 11.9A
Ipk is 17.2A. (+/-17.2A)
Bpk is 0.166T. Will the core losses be too excessive?
There are fans but not mounted right next to this inductor.
I can reduce the Bpk to 0.142T by using the 1.5mm gap ETD59 (AL = 381) and winding 8 turns.....but i thought the bigger gap will give more fringing flux problems?
--- Updated ---
On the same type of subject...
Hi,
We need ETD59 in N87 material ungapped.
However, ungapped is only available in 3C90
At 100kHz and 200mT, N87 is at 350kW/m^3, whereas 3C90 is at 450kW/m^3
That would mean the 3C90 ETD59 core dissipating 23W, but the N87 ETD59 dissipating 17.9W.
Would you say, with those dissipations, that even with a fan right on it, either 3C90 or N87 would go over the Curie temperature, and the transformer coils all go short circuit?
3C90
N87
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