CHAPTER VIII 

 THE INDUCTION MOTOR 



98. Principle. The induction motor is the most widely used 

 type of alternating-current motor. This is due to its ruggedness 

 and simplicity, to the absence of a commutator, and to the fact 

 that its operating characteristics are well adapted to constant- 

 speed work. 



Motion 



Direction of rotation 



of diio with respect 



to magnet 



Force 



Direction of rotation 

 of magnet 



Belatlre 



motion of 

 conductor with 

 respect to *- 

 magnetic pole 



22DJ 



(4) 



Direction of rotation 

 of dlic 



217. Rotation of metal disr produ< ,-<! l.y rotating magnet. 



Tin- principle of the motor may be illustrated as follows: A 

 metal di>c. I ig. 217 (</ to turn upon a vertical axis. The 



:nay be of any conducting material, such as iron. copier, or 

 aluminum. A magnet, five to rotate on thr 

 disc, is placed abov the disc and its ends are l>ent down so that 

 tie flux cuts through the disc. When this magnet is 

 rotated, (lie it lines cut the disc and induce currents in it, 



is 225 



