On Mar 3, 6:11*pm, Jim Yanik wrote:
the savings is in not having to build an expensive,big transformer.
all that copper is expensive,too.
transformers,being far less complicated,are more reliable.
Inverters have a lot more components,particularly electrolytic caps,that
increase the odds of failure.

Microwave oven transformers are really quite undersized by
conventional engineering standards for the amount of power going
through them. Years of experience with the intermittent application
and detailed electrical+mechanical+thermal engineering for some
overtemp shutdowns is why they don't burn out despite being
undersized.

I suspect that with some experience under the belt that the inverters
can be made as reliable.

A lot of early consumer switching supplies weren't that good in their
first iterations either - electrolytics was at least one cause of the
problems.

Tim.