Saturday, 30 April 2016

Some Essential Parts of an AC generator

  • Armature

Armature  is  a  rectangular  coil  consisting  of  a  large  number  of loops  or  turns  of  insulated  copper  wire  wound  over  a  laminated  soft iron core or ring. The soft iron core not only increases the magnetic flux but  also  serves  as  a  support  for  the  coil.
  • Field  magnets

The necessary magnetic field is provided by permanent magnets in the  case  of  low  power  dynamos.  For  high  power  dynamos,  field  is provided  by  electro  magnet.  Armature  rotates  between  the  magnetic poles such that the axis of rotation is perpendicular to the magnetic field.

  • Slip  rings

The  ends  of  the  armature  coil  are  connected  to  two  hollow metallic  rings  called  slip  rings.  These  rings  are  fixed  to a shaft, to which the armature is also fixed. When the shaft rotates, the slip  rings  along  with  the  armature  also  rotate.

  • Brushes

 There are two flexible metallic plates or carbon brushes. They provide  contact  with  the  slip  rings  by  keeping  themselves  pressed against  the  ring.  They  are  used  to  pass  on  the  current  from  the armature  to  the  external  power  line  through  the  slip  rings.