abdo799 said:I think the motor and generator will differ in the position of the brushes
Faulty logic there, I'm afraid. When you have max emf, you want to be making use of it all the time. You use it for as long as it is in the same direction - i.e. until it is near zero. The direction of the emf will change after the zero crossing so that's when you want to switch over the connection. Then the current will be flowing in the same direction as before, through your external circuit - whichever angle the commutator is at.abdo799 said:I still don't know why we put the brush at the point where the current is 0, we need max output so we should put it where the emf is max right?
The position of brushes is important because it determines the flow of electrical current through the generator. The brushes are responsible for transferring the current from the rotating armature to the external circuit. If the brushes are not positioned correctly, it can result in inefficient operation of the generator and can also cause damage to the commutator and brushes.
The correct position of brushes can be determined by the direction of rotation of the armature. The brushes should be placed at the point where the polarity of the armature changes from positive to negative. This point is known as the neutral plane. It can also be determined by using a commutator gauge or by trial and error method.
If the brushes are not in the correct position, it can cause sparking and arcing on the commutator, which can lead to damage and wear of the brushes and commutator. It can also result in uneven distribution of current, leading to inefficient operation of the generator.
The position of brushes should be checked and adjusted regularly, especially if the generator is in frequent use. It is recommended to check the position of brushes every 6 months or after every 500 hours of operation. However, if there are signs of sparking or inefficient operation, the position should be checked and adjusted immediately.
Yes, the position of brushes can affect the output voltage of a DC generator. If the brushes are not in the correct position, it can result in an uneven distribution of current and lead to fluctuations in the output voltage. This can also impact the overall efficiency of the generator.