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Rick89
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Hi, could someone give me a hand with the two long commutators on page 25 of Peskin and Schroeder? I'm not sure how to deal with the gradient in the first and the laplacian in the second. Thanx alot
Rick89 said:Hi, could someone give me a hand with the two long commutators on page 25 of Peskin and Schroeder? I'm not sure how to deal with the gradient in the first and the laplacian in the second.
Rick89 said:sorry, I'm not sure I see what u mean. I understand how to pass from the first to the second expression of the Hamiltonian used by "integrating by parts" the grad term. But my problem is how to handle the commutators.
A commutator is a mechanical device that helps to change the direction of current flow in an electric motor. It consists of a set of copper segments connected to the ends of the armature windings, which are then connected to the brushes that make contact with the segments.
When the armature rotates, the commutator segments make contact with the brushes, causing the direction of current flow to change. This allows the motor to continuously rotate in the same direction, as the commutator ensures that the current always flows through the armature windings in the same direction.
One common problem with a commutator is the buildup of carbon deposits on the segments, which can cause the motor to run less efficiently or even stop working altogether. Another issue is the wear and tear of the brushes, which can lead to poor contact and a decrease in motor performance.
To maintain a commutator, it is important to regularly clean it to remove any carbon buildup. This can be done by gently scraping the segments with a small tool such as a toothpick or using a specialized commutator cleaning tool. It is also important to regularly replace worn-out brushes to ensure good contact with the segments.
Yes, a damaged commutator can be replaced, but it is a complex and delicate process that should be done by a professional. It involves disassembling the motor, removing the old commutator, and installing a new one. It is important to also check for any underlying issues that may have caused the damage to the commutator.