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Offline SMPS with two isolated transformers that are too wide for the PCB

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We have an offline SMPS PCB which needs two transformers on it. Both of these transformers have isolated outputs, so therefore both must “straddle” the mains isolation barrier.

The problem is that if the isolation barrier is a straight line running across the PCB, then the two transformers will not fit on the PCB (as shown in the attached diagram).

The PCB is too narrow to fit both transformers on.

Therefore, we wish to make the mains isolation barrier “bent” as also shown in the attached diagram. –This way we can fit the two transformers on the PCB.

However, we worry about noise issues of this unusual shaped isolation barrier. ( noise coupling from primary to secondary side and creating a bigger common mode noise problem). Another point would be where the Y capacitor should go in this “bent” isolation barrier arrangement, so as to best couple noise back to the primary side?

Do you believe that this “bent” isolation barrier is OK?



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Most Helpful Member
Do you believe that this “bent” isolation barrier is OK?
Yes, I believe, I believe.

Why don't you try something like this, with a "U" shaped barrier?
Isolation Barrier.png

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