A laminated steel magnetic circuit has two air gaps and requ

A laminated steel magnetic circuit has two air gaps and requires 0.08 mWb in the air gaps for the armature to close. Figure 3 shows the shape and thickness of the magnet and the 2000 turn coil. Neglecting fringing and leakage, solve the following. a) Draw and label the equivalent magnetic circuit. b) Calculate the flux densities to be established in the air gaps and the two parts of the steel 3. c) d) e) f) g) magnetic circuit. Calculate the magnetic field intensity in the two steel parts. Calculate the mmf drops of the two steel parts Calculate the reluctances of the airgaps. Calculate the mmf drops of the airgaps. Calculate the coil current required for the armature to close. The magnetic characteristics of the laminated core are given below. 085 1.0 1.15 1.3 B(T) H( A.t/m) 0.85 560 800 1280 1950

Solution

b) flux density = flux /area

flux density in air gap = flux in air gap/area

= 0.08/ 25

= 0.00375

c) H = NI/L

d) mmf = N1*I1

for steel = N2*I2