identically the same as in the other cases described. This arrangement results in an increased speed of rotation.
In Figure 17, for example, the terminals of each set of field coils are connected with the wires to the armature coils in such way that the field coils will maintain opposite poles in advance of the poles of the armature.
In the drawings the field coils are in shunts to the armature, but they may be in series or in independent circuits.
It is obvious that the same principle may be applied to the various typical forms of motor hereinbefore described.
Figure 19 is a diagram similar to figure 9, illustrating a modification in the motor. In this figure the various parts are the same as in figure 9, except that the armature core of the motor is wound with two coils at right angles to each other, the core being a cylinder or disk. The two coils form independent closed circuits. This arrangement of closed induced circuits will be found to give very efficient results.
When a motor thus constructed is not loaded, but running free the rotation of the armature is practically synchronous with the rotation of the poles in the field, and under these circumstances very little current is perceptible in the coils E E', but if a load is added the speed tends to diminish and the currents in the coil are augmented so that the rotary effort is increased proportionately.
