In article op.tmmhywbk4buhsv@fx62, "Peter Hucker"
wrote:

On Tue, 23 Jan 2007 16:49:43 -0000, Snap Whipcrack..............
wrote:
Microwave ovens don't care what you put inside. They do not have
feedback loops. You can cook a raisin or a melon or nothing at all.

But where do you think the power ends up if it is not absorbed?

Peter-

If there is nothing in the microwave, there is no load, or at least very
little. If there is no load, there is no power dissipated. It is
somewhat like having 120 VAC at the wall socket with nothing plugged-in.

The problem isn't heat as much as voltage. With no load, the magnetron
voltage will be higher than normal. The question is really whether or
not damage will occur from over-voltage.

Someone in another thread a few weeks ago, said that only very early
microwave ovens would be damaged by running them empty. I know that one
I bought in 1976 came with a warning about running it empty, as well as
not putting anything metallic in it. However, two that were bought
about ten years ago did NOT come with such warnings, and even came with
metal racks!

Fred