106 



0.22 ohm, and the loss 1.65 per cent, of 

 the output. The speed of this machine 

 is 6,000 revolutions a minute, giving a 

 frequency of n = 100. The armature 

 weighs 360 lbs., and the weight of the 

 complete machine, including the turbo- 

 motor, is about 2 tons. 



The Zipernowsky Alternator. 



This machine is very similar to the one 

 just described, the principal difference 

 being that, instead of a smooth core, the 

 armature is provided with a core having 

 Pacinotti projections on the inside. The 

 magnet cores N S, Fig. 26, are composed 

 of U-shaped iron plates, to avoid the heat- 

 ing which would otherwise result from 

 the employment of an armature with pro- 

 jections. The core of the armature is 

 formed of thin sheet-iron segments A, 

 each resembling a very short or shallow 

 T, the armature coil C being placed over 

 the central stem of the T. Each arma- 

 ture-segment with its coil forms a sepa- 

 rate part, which can be inserted or with- 

 drawn without disturbing the rest of the 



