Original poster: Steve Conner <steve@xxxxxxxxxxxx>
So my question could you make the transformers to
power a tesla coil be air cored?
Yes. It's possible to make completely air-cored solid state Tesla coils.
There is no HV transformer needed- the coil itself is the step-up
transformer and it could run directly off 30V DC. The high frequency
inverter that drives it can be very small and light too.
However, they may not be the best solution. An air cored transformer needs
to be resonant, and that implies higher current flow for the same output. A
Q of 6 is usual, and that means the wire is carrying 6 times more current
than a non-resonant transformer or C-W multiplier would. So it needs to be
thicker, hence heavier, if it's not to burn out.
Ferrite transformers will work well even if non-resonant. So, while
ferrites are heavy, I would bet they would save more than their own weight
in copper. These are calculations _you_ will have to do if you're
interested in getting an autonomous lifter off the ground ;)
But I notice that military and space HV supplies- where weight really
counts- are all made with a HF inverter driving a ferrite transformer that
drives a C-W multiplier stack.
Then another question is could you make the toroid on
the tesla coil be lightweight?
You don't always need one. Sometimes the self capacitance of the coil is
enough, if not you can add a series string of small ceramic disc caps. If
you use a ferrite transformer then you definitely don't need one ;)