On 8/6/2017 5:50 PM, Leif Asbrink wrote:
The transformer can have a single turn on the primary. In that case, make a short tube that fills most of the inner diameter of the toroid. Distribute the secondary winding evenly over the toroid. That would minimize the leak inductance.
You can even use the loop itself as primary, like in this photo...
In this case the transformer had only two turns as secondary, may be more would have resulted
in a greater efficiency...
73 Alberto I2PHD
Credo Ut Intelligam