SMPS with toroid transformer

[kubeek]

Hi, I would like to build a SMPS, but since I don´t have any EE or EI cores available, I was thinking about winding a transformer on a toroid core.
Is for example toroid T200-26 up to the task, and what power could I expect form such core say at 50kHz and 100kHz? How do you calculate/guess that?

[lorylaci]

Originally Posted by kubeek

Hi, I would like to build a SMPS, but since I don´t have any EE or EI cores available, I was thinking about winding a transformer on a toroid core.
Is for example toroid T200-26 up to the task, and what power could I expect form such core say at 50kHz and 100kHz? How do you calculate/guess that?

There is a quess for transformer power:
P=k*Ae^2*f

(where if Ae is in cm^2 and f is in kHz, then k for half-bridge resonant is 4, for flyback its about 1)

I don't really know this core, but you should look for its datasheet and calculate its losses at 100kHz. You should look for some ferrite-cores, they have much lower losses! (or try Vacuumschmelze: Home*-*VACUUMSCHMELZE GmbH & Co. KG
You can order (buy) samples from them.

[kubeek]

I hopefully found a source of Epcos ETD ferrtie cores, so the core should no longer be an issue.
Do you know some reliable SMPS schematic that I could use? I am planning for easily scalable 150-500W supply to power a bridged D-class single channel amp, so the output votlage will be in the order of 60V. Is it a good idea to implement PFC, or is that unnecesary?
I was thinking of using a computer PSU schematic as a starting point, but am not sure if that is a good idea.