SEPARATE EXCITER MOUNTED ON MAIN SHAFT.

195  STANDARD ELECTRICAL DICTIONARY. The field-magnets whose windings may be in series are often excited by a separate direct current generation. Some are self-exciting, one or more of the armature coils being separated from the rest, and connected to a special commutator, which rectifies its current. By properly spacing the coils with respect to the poles of the field, and connecting each set of coils by itself to separate connecting rings, several currents can be taken from the same machine, which currents shall have a constant difference in phase. It would seem at first sight that the same result could be attained by using as many separate alternators as there were currents to be produced. But it would be almost impo ible to preserve the exact relation of currents and current overrun each other or would lag behind. In a single machine with separate sets of coils the relation is fixed and invariable. IMG:8956969607833025625_195F135.jpg: Fig. I35. DIAGRAM OF ARRANGEMENT OF ARMATURE COILS AND