N_Cook wrote:



So like a smaller version of a central heating circulation pump,
magneticc oupling through a membrane. At least washing m/c get used
through the summer , so nver a chance to seize up

Well, I've seen magnetic-coupled pumps. These have a totally standard
induction motor turning a magnet outside the housing, and a magnet turning
the impeller inside.

This is different - there is only one magnet, and the stator poles outside.
So, it is a 2-pole permanent magnet synchronous motor. The only trick is to
make sure the thing starts every time power is applied.

Jon