[time-nuts] Building a mains frequency monitor
Hal Murray
hmurray at megapathdsl.net
Mon Apr 11 01:59:30 UTC 2016
cfharris at erols.com said:
> A more modern name for a synchronous motor is a permanent magnet stepper
> motor. Any PM stepper, and a couple of microfarad capacitor becomes a
> synchronous motor when connected to the power line.
The old pre-digital way of generating a rotating field for a synchronous
motor was a shaded pole. They worked well for low torque applications like
clock motors. I saw plenty of them when I was a kid. The rotor was hidden
in a package with the first layer of gears. I assume it was a permanent
magnet but never took a package apart to verify that.
Good pictures here:
https://en.wikipedia.org/wiki/Shaded-pole_motor
--
These are my opinions. I hate spam.
More information about the Time-nuts_lists.febo.com
mailing list