Transformer Main Parts
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How to rewind Three-Phase induction stator.
How to rewind Three-Phase induction stator. Introduction: Three-Phase induction motor or asynchronous motor is a 3 phase AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. The course consists of the following lessons: Taking Data, Core Testing, Coil Cutoff, Burnout Procedures, Winding Stripping Procedures, Core Preparation, Coil Making, Winding Insulation and Coil Insertion, Internal Connections, Lacing and Bracing of Windings, Inspection of Untreated Windings, Testing Untreated and Treated Windings, Winding Treatment. Tools and equipments; Megger tester, cutter plier, a note book, oven, combination plier, insulators papers. Lesson 1: Taking Data, the key objective is to accurately determine winding data for a three phase stator, including connection, turns, span(s), wire sizes, poles, and grouping; and core and coil dimensions....
Corona effect on transmission line.
Corona When an alternating potential difference is applied across two conductors whose spacing is large as compared to their diameters, there is no apparent change in the condition of atmospheric air surrounding the wires if the applied voltage is low. However, when the applied voltage exceeds a certain value, called critical disruptive voltage, the conductors are surrounded by a faint violet glow called corona . The phenomenon of corona is accompanied by a hissing sound, production of ozone, power loss and radio interference. The higher the voltage is raised, the larger and higher the luminous envelope becomes, and greater are the sound, the power loss and the radio noise. If the applied voltage is increased to breakdown value, a flash-over will occur between the conductors due to the breakdown of air insulation. The phenomenon of violet glow, hissing noise and production of ozone gas in an overhead transmission line is known as corona . If the conductors are polished and sm...
cellular network
A cellular network or mobile network is a communication network where the last link is wireless. The network is distributed over land areas called cells, each served by at least one fixed-location transceiver , known as a cell site or base station . This base station provides the cell with the network coverage which can be used for transmi ssion of voice, da ta and others. In a cellular network, each cell uses a different set of frequencies from neighboring cells, to avoid interference and provide guaranteed bandwidth within each cell. When joined together these cells provide radio coverage over a wide geographic area. This enables a large number of portable transceivers (e.g., mobile phones , pagers , etc.) to communicate with each other and with fixed transceivers and telephones anywhere in the network, via base stations, even if some of the transceivers are moving through more than one cell during transmission. ...