"David Lesher" wrote in message
news
"Jim Wilkins" writes:


AC line filters reduce higher harmonics but have little effect at
the
fundamental frequency. The components simply aren't big enough to
store much energy and return it later.

Ferroresonant transformers are 60 Hz sine wave filters with voltage
regulation, but look at the weight:
http://www.hammondmfg.com/CVR.htm

And their output voltage is a function of frequency; so when the
generator speed varies. It's also difficult to design F-R tanks
to deliver sine wave output.

They work well enough to have survived on the market, but I don't see
them as a practical DIY project to clean up a modified square wave
(what they really are) inverter unless you find a suitable second-hand
unit cheap and have the gear to test it. My old Sola constant voltage
isolation transformer isn't nearly big enough to start my fridge's
compressor, which draws 12A for 0.3 seconds.

https://public.magnet.fsu.edu/graf/M...Tranformer.pdf
"In general, the Sola constant voltage
regulator must have a capacity nearly equal to the
maximum demand made on it, even for an instant. "

-jsw