No. 62 904. 



Alternating and Three-phase Current. 



1001 



62 902 C. 1:3. 



62902D. 1:3. 



62902E. 1:3. 



62.901. Lantern Slides for Explaining the Connections and Mode o! Action of Generator 

 No. 62,896, of A. C. Motor Model No. 62,898 and of the Demonstration Apparatus for 

 rotary field experiments, No. 62,902 (W. D. Figs. 579581, 583587, 596 and 598). 



Each 



(a) Alternator (Fig. 579), 



(b) Magnetic Axis of the Alternator (Fig. 580), 



(c) Stator Winding of the Three-phase Machine I (Fig. 581), 



(d) Curve for Mono-phase A. C. (Fig. 583), 



(e) Curve for two-phase A. C. (Fig. 584), 



(f) Curve for three-phase Current (Fig. 585), 



(g) Star and Delta Connection (Fig. 586), 



(h) Stator Winding of three-phase machine II (Fig. 587), 

 (i) Connections used as three-phase motor (Fig. 596), 

 (k) Connections used as mono-phase motor (Fig. 598). 



62.902. Demonstration Apparatus for Rotating Field Experiments (Battery A. C. Apparatus), 



after Weinhold, Figs. A E (Ztschr. f. d. phys. u. chem. U. 6, p. 7; W. D. Fig. 582) 

 The complete apparatus consists of: current distributing apparatus, Fig. A; Ferraris Double Coil 

 Fig. B; Ferraris triple coil, Fig. C; 4-coil iron ring, Fig. D; 6-coil iron ring, Fig. E; magnetic needle 

 and sheet-iron disc with agate cap; squirrel-cage rotor; glass disc with iron filings. 



The apparatus permits of carrying out the Alternating and Three-phase Current experiments in 

 a convenient and practical manner. The following pertain to the apparatus: 1 2 Bunsen cells or an 

 accumulator the current of which is transformed into Alternating or Three-phase Current by the 

 distributing apparatus, Fig. A. This current flows through double or triple crossed different-coloured 

 wire rings, Fig. B or C, in which a magnetic needle or an iron disc can be inserted. The bodies in- 

 serted in the coils rotate under the influence of the rotating field. Instead of these iron rings an iron 

 ring can be attached consisting of four or six coils and wound' with covered wires of different colour 

 (Tesla Ring), Figs. D and E; with these it is possible to obtain synchronous rotation by inserting a 

 magnetic needle or an iron disc; or asynchronous rotation may be produced by an iron ring wound 

 with copper wire (short-circuited rotor). It is possible to show the migration of the lines of force of 

 the field in a very pretty manner by means of a glass disc over which iron filings have been strewn. 



62.903. - - idem, but with Weinhold Coils, for the Horizontal Projection Apparatus, instead 

 of the crossed coils after Ferraris (W. D. Fig. 592) 



62.904. Glow Wires for above (W. D. Fig. 591), consisting of three marble sockets, one with 

 one wire, one with two wires in star connection, and one with three wires connected in 

 delta, with protecting caps 



. s. d. 



0. 1.6 



5. 10. 



6. 0. 



0. 15. 



Cl. 2721, 2722, 



2723, 2742, 2725. 



