In message , Andy Dingley
writes
On Tue, 04 Sep 2007 00:10:34 GMT, raden wrote:

Total ******** - more volts - faster rotation

the shaded pole is the pair of thick copper wires on the laminations,
its there to determine the direction of rotation, it has no effect on
the speed

Shaded poles motors may be synchronous or non-synchronous, depending on
how their rotor is constructed. For the small low-torque models used to
drive timers, they're almost universally synchronous.

You have looked at the photo he linked to, I presume


Evenm the non-synchronous ones are pretty insensitive to increased
voltage, as they're limited by the magnetic saturation of the core.

I should have said "within a range" up to where they approach saturation
....

Of the boiler fans which run at two speeds (purge and full), most are
voltage controlled - its cheaper than having a second winding



--
geoff