Thane Heins BI-TOROID TRANSFORMER

[Myzter]

thanks very interesting post

[teslaalset]

That's a cool idea. Since the BTT follows known physics "laws" the simulation should give some interesting results.

A small update.
I added a traditional transformer layout, so a simultaneous comparison between the Thane's solution and a traditional trafo can be made more easy.
Exacly the same coils are used, with exactly the same currents. Also same materials are used.
The updated Femm file is attached.

Next is to interpret the flux densities and calculate coil voltages and current/voltage phases out of the currents and the flux results.

[CRANKYpants]

HI GUYS,

THE BITT IS ACTUALLY THE ABOVE (SMALLER) TRANSFORMER WITH AN AIR GAP BETWEEN IT AND THE OUTER TOROID RING SO THE FLUX PATTERN SHOULD BE VERY SYMMETRICAL.

I NOTICED IN THE BELOW VIDEO TEST THAT THERE IS INDEED FLUX IN THE OUTER RING ON NO LOAD AS THE FEMM SUGGESTS ALTHOUGH I WOULD HAVE NOT PREDICTED IT.
http://www.youtube.com/user/ThaneCHeins?feature=mhum#p/u/1/Eiu-dCe8bnA

CHEERS
T

[broli]

A small update.
I added a traditional transformer layout, so a simultaneous comparison between the Thane's solution and a traditional trafo can be made more easy.
Exacly the same coils are used, with exactly the same currents. Also same materials are used.
The updated Femm file is attached.

Next is to interpret the flux densities and calculate coil voltages and current/voltage phases out of the currents and the flux results.

Can I ask you to keep as much of your data you'll find in graphical form. A lot of people including me are FEMM illiterate, especially when it comes to lua scripting and extracting graphs from a FEMM model.

[teslaalset]

HI GUYS,

THE BITT IS ACTUALLY THE ABOVE (SMALLER) TRANSFORMER WITH AN AIR GAP BETWEEN IT AND THE OUTER TOROID RING SO THE FLUX PATTERN SHOULD BE VERY SYMMETRICAL.

I NOTICED IN THE BELOW VIDEO TEST THAT THERE IS INDEED FLUX IN THE OUTER RING ON NO LOAD AS THE FEMM SUGGESTS ALTHOUGH I WOULD HAVE NOT PREDICTED IT.
http://www.youtube.com/user/ThaneCHeins?feature=mhum#p/u/1/Eiu-dCe8bnA

CHEERS
T

Hi Thane, thanks for some assistance here.

I made core 2 twice as thin as core 1 because the flux generated by the primary coil splits into two paths to keep the flux density of core 1 identical to core 2.
In your design the flux generated by the primary coil causes the density in core 2 to be half that of the flux density of core 1.

Now, if I understand your principle correct, the BEMF flux caused by the secondary coils should not enter core 2. This means that core 2 should be saturated by the primary coil, right?
Now, in my view it would be better to half the diameter of core 2 to obtain such saturation in a larger portion of the total sinus period.
Can you advise here, if my assumptions are incorrect?