TRANSFORMERS 323 



The rofor must be clamped in the required position or it will 

 tend to rotate at a high speed in the direction opposite to that of 

 the revolving field. 



The advantage of the induction regulator over a transformer 

 with variable voltage taps on the secondary or primary is that the 

 variation of voltage is uniform over the entire range. Regulators 

 are, however, very expensive and require a large exciting current 

 and have large leakage reactances. 



The regulator is operated either by hand or by means of a 

 small motor placed on the top or it can be made automatic if 

 required. 



