Wild_Bill wrote:

AC PM motors don't exist, as far as I know. Even weed string trimmer
motors will utilize one diode for DC, when a PM motor is utilized, which
is all that's required without variable speed regulation.
A rectifier/diode after a variac (for example) will provide variable
speed, but not speed regulation.

FWIW, I once found one of those leaf blowers in the dumpster. I took
it home and took it apart - the plastic brush holders were melted. It
had a full-wave bridge rectifier (4 diodes).

Got a couple of way kewl magnets out of it! ;-)

Cheers!
Rich