ALTERNATING-CURREXT I. \XTRl' VENTS 



65 



that the flux is crowded to the left-hand side of the lug as shown. 

 When the flux starts to decrease, the current in the short-circuited 

 stamping tends to oppose the decrease in the flux. This retards 

 the time-phase of the flux in the right-hand side of the lug with 

 respect to that in the left-hand side of the lug. The result is 

 a sweeping of the flux from left to right across the lug. This 



00 





(O (6) (5) 



fu'l.i in air-gap of induction \vatth.ur 



sliding flux cuts the disc and sets up eddy currents in if. 

 currents, reacting with the flux, produce a tonpie tending t> 

 drive the disc in the direct ion in which the stampiim is displaced 



from tti pontioo of symmetry, Thi- ifl ih- ">hadrd-pole" 

 principle which is also used to start small single-phase ii id ut mn 

 mot , I i!. Page 298.) 



