AXALYSIS OF PT'LL AND MACXKTIZ ATIO.N M i; AST 1{ i:.M i;.\'rs 



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COIL ABAMPERE TURNS, 'J/^n 



Fig. 8 — delation of core potential drop to applied magnetomotive force. 



To the extent that the physical stnictiire may be identified with the 

 corresponding magnetic circuit element, the drop in magnetic potential 

 in the core may be identified with (Rc^ in Fig. 5. Assuming this identifi- 

 cation to apply, magnetic probe measurements may be made at the two 

 ends of the core, as at the points marked .Y in Fig. 2. The potential drop 

 observed in these measurements is the magnetic potential ^e applied to 

 the external magnetic circuit. CF^ is eciual to the applied magnetomotive 

 force 5(or 47riV/) less the potential drop ^r = (Rrv? in the core. Thus 

 ;Tc = ^ — ^E- Values of JFc/(47r) thus determined for the relay of Fig. 2 

 are shown plotted against JF/(47r) for various values of x. in Fig. 8. These 

 curves are substantially linear in the low density region: their upward 

 conca\at3'' at higher values of JT is evidence that saturation first occurs in 

 the core. 



Ei'alua(ion of Core Relucatance Consfants 



The magnetization curves of Fig. 1 and the core magnetomotive force 

 turves of Fig. 8 were obtained with the same model. For given values of 

 ■J and .}; there can be read from these two figures corresjxjudiiig \alues of 



