Below some interesting videos from Potential Difference Inc (PDI) Canada which shows the effect...

These videos are published by courtesy of Thane C. Heins CEO of PDI Canada.

BI TOROID TRANSFORMER vs CONVENTIONAL TRANSFORMER by Thane C. Heins

OTTAWA UNIVERSITY BIONYX ReGenX Electric Bike Test

MIT Dr Zahn Bi Toroid Transformer Tutorial

OTTAWA UNIVERSITY - BI-TOROID DEMO

Link to The Thane C. Heins Bi-Toroïd patent

The Electric Vehicle Regenerative Acceleration (ReGenX) demo by Thane C. Heins

Link to the patent of the "Perepitea" motor/generator from Thane C. Heins

to the project page