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In a series DC motor used for traction, the armature rheostat is there to limit the current on starting. In normal running the rheostat is set to zero ohms (maximum power) so that power is not wasted in it. At full speed the power is turned off, the vehicle then coasts along until it's time to stop.
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Why the generator field rheostat kept at maximum position?
There is nothing to limit current until opposing magnetic fields build up at generator operating speed-windings will overheat and burn.
Would it be correct to say with a fixed field voltagethe speed of a shunt motor is proportional to its armature voltage?
With increasing torque load the armature tends to slow down; the motor draws more current to compensate, and if there is armature resistance the back emf generated by the armature falls to allow the increased current to flow, which causes the motor to settle at a lower speed. The mechanical output power is the speed times the torque, and increasing the torque increases the power output provided the speed does not drop much.
Example of embalmed abstraction in technical report?
Embalmed abstraction: The cylinder must be maintained in an upright position. Simple: The cylinder must be kept upright.
Why field winding work as stator and armature winding as rotor?
No, these can be switched depending on the requirements of the application. It is more practical to have the armature windings (since they will carry the full load current) as the stator for this will require larger wires and is also easier to cool if kept stationary. The field windings do not carry the full load current of the load so this requires smaller wires and smaller slip rings since this is the piece that will rotate.
What is the relation between inversion and neutral temperature?
inversion temperature Ti is twice the neutral temperature Tn.
