Thane Heins BI-TOROID TRANSFORMER

[broli]

I am not sure this design would work. Look at the flux from primary, the other secondary sees flux from primary and opposing flux from other secondary, they dont add up. Here is a 2d picture of what I mean.

I see now. These are the closests matching cores then:

2x Oval: M-284  >60000µ @ 50Hz 100 EUR

Toroid: M-028 ~30000µ @ 10kHz 100 EUR (25mm thick)
Toroid: M-115 ~30000µ @ 10kHz 120 EUR (30mm thick)
Toroid: M-615 >45000µ @ 10kHz 100 EUR (30mm thick)

So depending on which toroid you chose the price will be around 300 EUR (without shipping costs). It's not that much but you have to ask yourself what the COP will be and how much power you can take from these.

[futuristic]

Perhaps this version would be cheaper and more efficient?

[broli]

Perhaps this version would be cheaper and more efficient?

On the first page of this thread wojwrobel had a similar setup, but there's no experimental data of his setup.

[Jack Noskills]

I thought of this kind of setup too but I realised couple of problems:

Those smaller toroids, they touch each other much less than oval so it could be difficult to wind enough wire for primary coil, same thing for secondary.
Smaller toroids are inside bigger one. What happens if core heats up and there occurs thermal expansion ? I am afraid of core cracking here if fit is too tight.
Price of magnetec cores seem to be same regardless if core is oval or toroid.

Excellent picture broli, thanks for that.

[broli]

It would cost around 404â,¬ apperently if you include 19% taxes, shipping seems costless in europe. If more people can pitch in I'm willing to donate 100â,¬ for the project.