The field coils are connected in series or parallel with the armature winding.
Some older or simpler arrangements use a single field coil with a pole at each end.
With two suction cups he fixed a field coil over the area.
I'm turning on the field coils in exactly 2 minutes.
The outer field coils draw their power from the grid.
This field may be generated by either a permanent magnet or a field coil.
Most of these used a single transverse field coil mounted above the rotor.
His right went between the field coils and into the negatron stream.
Both dynamos and alternators required a source of power to drive their field coils.
"Anything you can do to fix the field coils in a hurry?"