Types of Armature Windings
The following terms used in connection with armature winding
should be kept in mind:
(A) Conductor: The length of a wire lying in a
magnetic field is called a conductor. It may be made of one or two or more
parallel strands.
(B) Turn: When the two conductors lying in a
magnetic field are connected in series, so that emf induced in them help each
other or the resultant induced emf becomes double (assuming full pitch coil) of
that due to one conductor, it is knows as a turn.
(C) Coil: When one or more turns are connected
in series it is termed as a coil. The group of wires or conductors constituting
a coil side of a multi-turn coil is wrapped with a tape as a unit.
(D) Coil span or coil Pitch: It is the distance measured in terms
of armature slots or armature conductors between two sides of a coil.
(E) Pole pitch: it is defined as the number of
conductors per pole. If there are 24 conductors in a 4 pole generator then pole
pitch = 24/4 = 6
(F) Full pitch: if the coil span is equal to the
pole pitch then the winding is called full-pitched winding. Full pitched
winding have the advantage of giving maximum emf induced because, the coil
sides of a coil lie under opposite poles.