mallick.subratkumar

 Profile Answers by mallick.subratkumar Questions by mallick.subratkumar

• Apr 8th, 2010

 

For dc motor there are three types of speed control
1.Field flux control.
2.supply voltage control.
3.armature control.
 In armature control we use series resistance with motor ,by this method the speed is contorlled above rated.but field control is used for below rated speed.
if we take control system then by armature control there is a feedback,
but in field control there isn't.
so we always prefer for a greater stability therefore we take armature control.

ravs42

 Profile Answers by ravs42 

• Aug 8th, 2010

 

In case of field control method, a rheostat is connected in series with d field winding. There is a particular limit for the field flux dat is been controlled by the rheostat. A very high flux may lead to the saturation of the magnetic circuit and a flux that is been produced by the rheostat having value less than the critical resistance make no sense as it may not be sufficient to produce apt field for armature, so not preferable. Armature control method too has got a demerit that it reduces the efficiency of the system due to I2R losses.

AHORDZI ERIC

• Nov 20th, 2013

 

What is ammeture reation

chiragmistry

• Mar 14th, 2014

 

In case of the dc motor the armature control mathod is used blow the based the motor is run below the based speed Because,above based speed motor react as generator.