STANDARDlZArio.\ Ri'l.i HI: A.I / 



C, DEFINITIONS. STATIONARY INDUCTION APPARATUS. 



22 STATIONAKN IM>I IION APPARATUS changes electric energy to electric 

 energy through the medium of magnetic energy. It comprises several 

 forms, <i <*d as follows: 



23 a. TRANSFORMERS, in which the primary and secondary windings are 

 insulated from one another. 



23* A PRIMARY \\IMHM. is that winding of a transformer, or of an 



induction motor, which receives power from an external source. 



23b A SECONDARY WINDING is that winding of a transformer, or ot an 



induction motor, which receives power from the primary by 

 induction. 



Note: The terms " High -voltage winding " and " Low-voltage 

 winding " are suitable for distinguishing between the windings of a 

 transformer, where the relations of the apparatus to the source of 

 power are not involved. 



24 6. AUTO-TRANSFORMERS, also called compensators, in which a part 

 of the primary winding is used as a secondary winding, or conversely. 



26 (. POTENTIAL REGULATORS, in which one coil is in shunt and one 

 in series with the circuit, so arranged that the ratio of transformation 

 between them is variable at will. They are of the following three classes: 



26 1. CONTACT VOLTAGE REGULATORS, also called Compensator Reg- 

 ulators, in which the number of turns in use of one of the coils is 

 adjustable. 



27 (2) INDUCTION POTENTIAL REGULATORS in which the relative 

 positions of the primary and secondary coils are adjustable. 



28 (3) MAGNETO POTENTIAL REGULATORS in which the direction 

 of the magnetic flux with respect to the coils is adjustable. 



29 d. REACTORS or REACTANCE COILS, also called choke coils, are a form of 



lonary induction apparatus used to supply reactance or to produce phase 

 displacement. 



29a f. AN INDUCTION STARTER is a device used in starting induction motors, 

 converters, etc., by voltage control, consisting of an auto-transformer com- 

 bined with a suitable switching device. 



29b A LEAKAGE REACTANCE or SERIES REACTANCE is a portion of the reac- 

 tance of any induction apparatus which is due to stray or purely self -in- 

 ductive flux. 



D. GENERAL CLASSIFICATION OF APPARATUS. 



30 COMMUTATIM. M Under this head may be classed the follow- 

 ing: Direct-current generators; direct-current motors; direct-current boost- 

 ers; motor-generators; dynamotors; converters; compensators or balancers; 

 closed-coil arc machines, and alternating-current commutating motors. 



31 Commutating machines may be further classified as follows: 



32 a. DIRECT-CURRENT COMMUTATING MAC MINES, which comprise a mag- 

 netic field of constant polarity, a closed-coil armature, and a multiseg- 

 mental commutator connected therewith. 



33 /.. Al.TERNATING-Cl RRENT COMMUTATING MACHINES, which Comprise a 



magnetic field of alternating polarity, a closed-coil armature, and a multi- 

 segmental commutator connected therewith. 



34 c. SYNCHRONOUS COMMUTATING MACHINES, which comprise synchronous 

 converters, motor-converters and double-current generators. 



33 - N< HKONOfs MACHINES, comprise a constant magnetic field, and 

 tture receiving or delivering alternating-currents in synchron- 

 ism with the motion of the machine; i.e., having a frequency equal to the 

 product of the number of pairs of poles and the speed of the machine in 

 revolutions per second. 



36 STATIONARY INDUCTION APPARATUS, include transformers, auto-trans- 

 formers, potential regulators, and reactors or reactance coils. 



37 ROTARY INDUCTION APPARATUS, or INDUCTION MACHINES, include ap 

 paratus wherein the primary and secondary windings rotate with re- 



