"Morgans" wrote in message
...

That is why I asked about the wave form. I was assured it was sine wave. I
still wonder. Usually they are proud of true sine wave, and advertise it.

From the Yamaha site: "
a.. Inverter System with Pulse Width Modulation - Industry-leading system
produces higher-quality and cleaner electricity. Results in pure sine wave as
clean or cleaner than commercial power and can operate products with built in
microcomputers."
a..
Note the words: " Results in pure sine wave". Yes, it is pwm (just like any
sine wave inverter I know of), but the resultant waveform is far cleaner than
you will get from most any other generator, particularly from any other consumer
grade generator.

If you look closely at the specifications & instructions that come with cheap
generators, you will often see verbage warning you about operating sensitive
equipment. This is because they can have distorted waveforms, off-frequency
operation, and poor voltage regulation. (That said, they often manage to do the
job amazingly well.)

This conversation started about refrigeration motors which can be quite fussy
about waveform, but it is little understood that modern electronics have
switching power supplies that can be pretty insensitive to waveform. Strangely,
your computer is more likely to run well off of your cheap inverter than your
refrigerator, even though both of them may require about the same wattage.

Vaughn



--
Jim in NC