[GreenKeys] M28 selector magnet wiring

[Jim Haynes]

On Thu, 24 Dec 2020, Nick England wrote:

> That is, the magnetic fields are in series through the armature, rather than
> in parallel attracting the armature.
> N1-S1-armature-N2-S2 (with tops of the magnets linked S2-N1 by the core)
> Is my thinking correct?
> 
You want the coils in series magnetically because the magnetic circuit is 
from one end of the armature, through the U-shaped core through the two 
coils, and then to the other end of the armature and through the armature 
back to the starting point.  Think of it like a horseshoe magnet 
attracting the armature.  If the coils were magnetically in parallel
they would have to attract the armature with the magnetic circuit going
through the hinge and the other metal parts to get back to the far end
of the coils.