Repeat Example 1.7 but find the current i for B_c = 1.6 T. By what factor does the current have to be increased to result in this factor of 1.6 increase in flux density?

EXAMPLE 1.7

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Assume that the core material in Example 1.1 is M-5 electrical steel, which has the de magne- tization curve of Fig. 1.10. Find the current i required to produce B₂ = 1 T. ■ Solution The value of Hc for B. = 1 T is read from Fig. 1.10 as H₂ = 11 A turns/m The mmf drop for the core path is Fe = Hele = 11(0.3) = 3.3 A-turns Neglecting fringing, Bg = B₁ and the mmf drop across the air gap is 1(5 x 10-4) = 396 A-turns 4 x 10-7 F₂ = H₂8 = The required current is i= B₂8 но Fe + F₂ N = 399 500 = 0.80 A = Assume that the core material in Example 1.1 is M-5 electrical steel, which has the de magne- tization curve of Fig. 1.10. Find the current i required to produce B₂ = 1 T. ■ Solution The value of Hc for B. = 1 T is read from Fig. 1.10 as H₂ = 11 A turns/m The mmf drop for the core path is Fe = Hele = 11(0.3) = 3.3 A-turns Neglecting fringing, Bg = B₁ and the mmf drop across the air gap is 1(5 x 10-4) = 396 A-turns 4 x 10-7 F₂ = H₂8 = The required current is i= B₂8 но Fe + F₂ N = 399 500 = 0.80 A =