Output and power laminations

[Mihkel]

I have studied how transformers are built by disassembling smaller ones and have noticed that power and output transformers have the EI laminations set up differently. A quick sketch to show you what i mean is in the attached picture.


Is there any specific reason why this is done differently?
Could output transformers have the laminations set up the same way?

Thanks

[novosibir]

Could output transformers have the laminations set up the same way?

In chokes and in SE output transformers this even is necessary - called 'air gap' - that the core doesn't run into saturation by the permanently applied DC to the coil. The downside: To reach a respectable inductivity, much more iron is needed than w/o air gap.

PP OT's can be smaller for the same power capability, because they don't have an air gap and nevertheless they are running into saturation, because the both DC currents fed in at the primary center tap are running in the coil vice versa and therefore an occuring premagnetisation is cancelling out each other.

Better can't explain with my German's English - but much better in German

Larry

[Mihkel]

Spreche im Deutsch dann, vielleicht kann ich etwas verstehen!