______________________________________________________________ Solid State Power Supplies
If frequency or inductance is increased, the XL increases. Since inductors are placed in
series with the load (see Figure 4-12), the larger the XL, the larger the AC voltage
developed across the load.
Figure 4-12. Voltage Drops in an Inductive Filter
4-35. When the current starts to flow through the coil, an expanding magnetic field
builds up around the inductor. This magnetic field around the coil develops the cemf that
opposes the change in current (see Figure 4-13).
4-36. When the rectifier current decreases (see Figure 4-14), the magnetic field collapses
and again cuts the turns (windings) of wire, thereby inducing current into the coil. This
additional current merges with the rectifier current and attempts to keep it at its original
level.
Figure 4-13. Inductive Filter (Expanding Field)
Figure 4-14. Inductive Filter (Collapsing Field)
23 June 2005
TC 9-62
4-13