[DennisCNC]

Any one here have experience with ferroresonant transformers and if they will be good for a power supply to drive Geckos?

Thanks

[Alexthehun]

I have used them in cable tv networks. These are usually either 60 or 90Vac output. They have the benefit of stabilising variations in load and input voltage, often up to +-10 percent.
Current capability is often in the tens of amps. Bear in mind that the output voltage is usually more or less square wave, so the rectified output voltage will be much more than a sinewave supply of the same voltage. (Close to the peak voltage of the square wave actually)
Provided that the rectified voltage suits your Gecko drives there should not be a problem using them.
Bear in mind one strange operating effect: if you use them under partial load, i.e. well below their rated current capability they tend to run hotter and noisier than on full load!!(this is to do with the circulating energy in the resonant section, but should not be a show stopper)

[D.L]

Just built one from a $25 flea market arc welder, it gives 62 volts and 40 amps.
Beat that for lunch money!

[bozidar22]

there is some information on cnc home page on rewinding a microwave transformer.