On 2006-12-28, PeterD wrote:
On 28 Dec 2006 09:09:15 GMT, jasen wrote:

On 2006-12-27, Roddy Meatstick.............. wrote:
Father Haskell wrote:
What goodies do I have?

See if you can figure out why they can't make a QUIET fan in a microwave.

it takes quite a breeze to cool the magnetron


Bye.
Jasen

The fan's job is more than cooling the magnetron. The blades of the
fan are used to disperse the microwaves inside the oven to help
prevent cooking hot spots. Some of the noise is due to the size of the
blades (they are more efficient at dispersing the microwaves than at
moving air!)

theyre doing them like that? I guess that explains much of the noise...

the one I pulled apart had a separate moulded fan mounted outside the oven cavity
and indide the cavity a wind driven stirrer,

Some microwave ovens with turntables have quieter fans because the
need to disperse the microwaves is less of a problem with the
turntable.


--

Bye.
Jasen