Roger Hayter wrote:

Andy Burns wrote:

how universal are the "so called" universal motors?

AIUI the only universal thing about them is that they could work on AC
or DC

Wouldn't a synchronous motor have "some difficulty" running on DC?

which is unlikely to be an available choice in the context. Just
a kind of brush using motor.

The phrasing of "universal microwave motor" rather than "microwave
universal motor" implies to me more about what it's intended to fit,
that how it works internally, but interested to hear other opinions ...