Generation of magnetic stress in the loop is a magnetic coil. As a conductor in a magnetic circle is an iron core. Air gap in this circle will be as magnetic resistor. The width of the air gap will affect the magnetic resistor. The road is closed magnetic field lines is called the magnetic loop (Figure 1.120). This circle can be compared with the current circle.
Figure 1.120 Circle magnet
Example: A coil is wound on the ring core steel castings as in Figure 1121 the cross sectional area of the ring pieces of 6mm and has a length of 55cm middle. A gap that is filled non-magnetic material with a thickness of 0.8 mm. Assuming no leaks magnet, how much MMF required to generate a flux density of 1,5T
Image 1,121 coils with Core Ring for Example Problem
Answer:
See Figure Magnetism Curve 1117, for B = 1,5T cast steel materials require H = 3000AT / m. So Amper his Lilit is 3000. 55. 10 -2 = 1650 AT. On slit required:
Lilit amperage required in the gap is
1.19. 106. 0.8. 10 -3 = 0.952. 10 3 = 952 AT
Total MMF required:
1650 + 952 = 2602 AT