MAGNETIC DKSKIN OF llELAYt? 



33 



ip_i can be considered as subdivided in turn into i^;^,i and ip,; icprcsentinjj; 

 respectively a leakage field from 2 to I, and a licld concentrated at the 

 air gap between these surfaces. 



These tubes of induction are analogous to the ( uiicnts in an clcctrii a! 

 network, and the applied magnetomoti\-e fori e is analogous to the 

 applied \'oltage pioducing these currents. The rehictances between 

 equipotential surfaces are analogous to the resistances of the electrical 

 network, and the potential differences between these surfaces are analo- 

 gous to the voltage drops in the electrical resistances. 



The field relationships in\ohed may therefore be represented as in 

 Fig. 3(b), in which the diagram of a resistance network indicates how the 

 component reluctances determine the relation between the applied mag- 

 netomotive force J and the resultant flux ^. The potential difference 

 between the points 1 and 5 at the ends of the coil is J less ^c where 

 (Re is the reluctance of the core. This net potential l)alances the drop 

 ^Lc (Rlc across the leakage path and the drop through the armature path, 



!♦ 3-=477NI 



(a) MAGNETIC FIELD SCHEMATIC 



V'LA 







^A 



ytcl 



y= 477- NI 



(51 LA 



-\/V\r 



«LC 



■A^ 



■A/VV 



(b) MAGNETIC CIRCUIT 

 Fig. .3 — Magnetic circuit rei)ieseiit;tt ion of magnetic field relations. 



