Why doesn't the DC generator build up , if it's output I'd short circuited

 

Maybe it's broken.

 

Build up???

 

Build up, I mean build up generator fields so the generator can produce rated voltage

 

Is it an auto dynamo, what happens when the field and dynamo output are connected together, it should self excite to full voltage?

 

Is the question referring to the failure of a self excited DC generator to self-excite with the output shorted. I would have thought that self-evident.

 

This relies on some residual magnetism in the armature. If it hasn't been used for a while this may have faded away. I'm not an expert on this but I think you have to apply some current through the armature windings (by connecting a car battery) to re-magnetise.

 

This relies on some residual magnetism in the armature. If it hasn't been used for a while this may have faded away. I'm not an expert on this but I think you have to apply some current through the armature windings (by connecting a car battery) to re-magnetise.

...... and just make sure that the battery applies the current to the armature in the right direction, else you'll back to square one.


Ramesh

 

This relies on some residual magnetism in the armature. If it hasn't been used for a while this may have faded away. I'm not an expert on this but I think you have to apply some current through the armature windings (by connecting a car battery) to re-magnetise.

I think it's the fields not the armature. In the old days we "flashed" the field terminal on the regulator when replacing a generator. Flashed meant to short between the battery and field connections. The fields are the 'magnet' and the armature is the power producer.