2.Rectification
(1)Mechanism of rectification of alternator
Construction
The actual alternator forms rectification circuit called rectifier as shown in figure 1 to rectify three-phase alternating current using six diodes. The circuit is built in the rectifier holder as shown in the figure.
Function
When rotor makes one turn in the stator coils, electricity is generated in each coil , positive (+) electricity is generated in coil III and negative (-) electricity is generated in the coil II. Therefore, current flows in the direction from coil II to coil III.
This current flows into a load via diode 3 and then returns to coil II via the diode 5. At this time, the electricity passing through coil I is 0. Due to this, no currents flows into coil I.
By the same logic, alternating current is rectified by passing through the two diodes each and a constant amount of current flows to the electrical load regularly.