Ans. A collection of inductors mounted on a shaft and arranged to rotate in a magnetic field with provision for collecting the currents induced in the inductors.
A simple loop or turn or wire may be considered as the simplest form of armature.
Ques. How do armatures and field magnets differ in dynamos and alternators?
Ans. A characteristic feature is that in the dynamo the field magnet is the stationary part and the armature the rotating part, while in the alternator the reverse conditions usually obtain.
Ques. With respect to this feature, what names are sometimes given to the armature and field magnet?
Ans. The stator and the rotor depending on which moves.
Ques. What is the real distinction between an armature and a field magnet?
Ans. The name field magnet is properly given to that part which, whether stationary or revolving, maintains its magnetism steady during operation; the name armature is properly given to that part which, whether revolving or fixed, has its magnetism changed in a regularly repeated fashion when the machine is in motion.
Construction of Dynamos.—In the make up of a dynamo, as actually constructed, there are five principal parts, as follows:
1. Bed plate; 2. Field magnets; 3. Armature; 4. Commutator; 5. Brushes.