Friday, November 11, 2011

Commutator Electric



A commutator is a rotary electrical switch in certain types of electric motors or electrical generators that periodically reverses the current direction between the rotor and the external circuit. In a motor, it applies power to the best location on the rotor, and in a generator, picks off power similarly. As a switch, it has exceptionally long life, considering the number of circuit makes and breaks that occur in normal operation.

A commutator is a common feature of direct current rotating machines. By reversing the current direction in the moving coil of a motor's armature, a steady rotating force (torque) is produced. Similarly, in a generator, reversing of the coil's connection to the external circuit provides unidirectional—direct—current to the external circuit. The first commutator-type direct current machine was built by Hippolyte Pixii in 1832, based on a suggestion by André-Marie Ampère.

Wednesday, November 9, 2011

What does CCCW stand for?

A sample of CCCW application - heat exchanger

What does CCCW stand for? CCCW stand for Closed Circuit Cooling Water. The reason in a power plant that have CCCW is for heat rejection system, which extracts waste heat to the atmosphere though the cooling of a water stream to a lower temperature.