CONTINUOUS AND ALTERNATING 

 CURRENT MACHINERY 



rllAlTKK I 



ELEMENTARY PRINCIPLES AND LAWS < >F CONTINUOUS 



CURRENTS 



1. The Electric Current. Everyone i- more or less 



familiar with some of the effects produced l.y an electric 

 current. The exact nature of the current it>ell' i< not 

 known hut the ina'.:n'tic action of a current, the heating 

 action of a current flowing through a conductor, etc.. have 

 IM-CII accurately >tudied and the laws according to which 

 the action- take place have been forinulated and i 

 experimentally. 



The four principal efYects of an electric current are: 



1. Production of a magnetic field. 



2. (ieneration of heat . 



3. Chemical action. 



4. Physiulogical action. 



A'/FM-/. Whenever a current flows a tnn<:- 

 is produced around the citmhictnr thmmjh which the 

 current is flowing; a compass needle placed near the con- 

 ductor carrying current will be deflected by such a field 

 and the deflection will cease as soon as the current stops 

 flowing. 



