View Single Post
Old 26th Aug 2018, 2:19 pm   #14
julie_m
Dekatron
 
Join Date: May 2008
Location: Derby, UK.
Posts: 7,735
Default Re: Westclock direction

Well, that's really shooting cannons at sparrows, as they say in Düsseldorf!

So assuming I have counted right and estimated right where I could not see to count, it starts as a 12-pole shaded pole induction motor, which would max out at about 470 rpm (just shy of 3000 / (12/2) = 500) and always starts in the same direction by dint of the shading. But there is also a 30-pole synchronous element which will take over as soon as the spindle speed gets up to 400 rpm (the permanent magnet has 4 poles, so we are dividing our 3000 cycles/minute by 30/4 here).

It's all very clever, but still leaves me thinking there must be a simpler way of doing it!
__________________
If I have seen further than others, it is because I was standing on a pile of failed experiments.
julie_m is offline