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Electrical Aspects
Published in Frank R. Spellman, The Science of Wind Power, 2022
The electromagnet is of great importance in electricity simply because the magnetism can be “turned on” or “turned off” at will. The starter solenoid (an electromagnet) in automobiles and powerboats is a good example. In an automobile or boat, an electromagnet is part of a relay that connects the battery to the induction coil, which generates the very high voltage needed to start the engine. The starter solenoid isolates this high voltage from the ignition switch. When no current flows in the coil, it is an “air core,” but when the coil is energized, a movable soft-iron core does two things. First, the magnetic flux is increased because the soft-iron core is more permeable than the air core. Second, the flux is more highly concentrated. All this concentration of magnetic lines of force in the soft-iron core results in a very good magnet when current flows in the coil. However, soft iron loses its magnetism quickly when the current is shut off. The effect of the soft iron is, of course, the same whether it is movable, as in some solenoids, or permanently installed in the coil. An electromagnet then consists of a coil and a core; it becomes a magnet when current flows through the coil.
Controls
Published in Carl Bozzuto, Boiler Operator's Handbook, 2021
The generator works by moving a conducting wire through a magnetic field. The magnetic field is created by an electromagnet. In commercial generators, the electromagnet is rotated, while three sets of windings around the rotating magnet interact with the magnetic field to induce a current. From an electrical point of view, this produces three-phase current flow. Think of it as positive, negative, and ground, although that is not precisely correct. That current flow goes to a transformer that increases the voltage for transmission to the end users. At the user end, there are transformers that step down the voltage to the required levels for industrial plants, commercial buildings, and home use. The voltage is maintained constant at the generator, while the current increases or decreases to meet the demand. There is a governor on the generator that detects the demand level and increases or decreases the strength of the magnetic field through the electromagnet.
Fly-by Bridge Inspection using UAVs (standalone portable system)
Published in Airong Chen, Xin Ruan, Dan M. Frangopol, Life-Cycle Civil Engineering: Innovation, Theory and Practice, 2021
Y.M. Mohammed, C. Tan, N. Uddin
The proposed perching mechanism consist of small lift sucking solenoid electromagnet that able to hold 0.5 kg. The electromagnet weight is 15g and the input volt is 5-12 DC. To resist high temperature produced by the electromagnet wire the framework is made from nylon plastic which has high temperature resistance and covered by pure iron box. It should be noted that the electromagnet should has very small weight so the drone can fly. The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field.
On the temperature analysis of magnetic abrasive finishing of aluminum 6060 using finite element method
Published in Machining Science and Technology, 2020
Rajneesh Kumar Singh, Swati Gangwar, D. K. Singh
The next step is to assign the boundary condition of the magnetic flux density analysis and flux parallel applied on surface of the Air pocket. The magnetic field generated by applying current to the coils of electromagnet. The density of magnetic flux depends on the current magnitude and number of turns in coil. Load in the form of current (A) is applied on the electromagnetic tool coil for the simulation of magnetic flux distribution. Value of current (3 A–6 A) fed to the magneto-static 3D model for different trial conditions from Table 2. Number of turns of coil and surface area are remained constant as charge density of current depend on them. Figure 6 shows simulated distribution of magnetic flux density in 3D physical model of electromagnet. Distribution of magnetic flux is predominant in the electromagnetic core and FMAB. At the same time, the distribution of magnetic flux is negligible in coil and workpiece as they are non-magnetic material.
Influence of nanoparticles on emission and performance characteristics of biodiesel-diesel blends in a DI diesel engine
Published in Australian Journal of Mechanical Engineering, 2022
Harish Venu, Prabhu Appavu, Venkata Ramanan M, Jayaprabakar Jayaraman
The instrument used to measure the output power is dynamometer, which has a stationary rotor bounded by electromagnets and coupled with crankshaft by flexible coupling. The rotor’s rotary motion acts against the magnetic field generated by the electromagnet when supplied with sufficient electric current. This in turn creates resistance to rotor and thereby happens to apply load to engine. Hence, varying the current supplied to electromagnet can alter the load. The opposing force created on dynamometer is measured by the change in strain gauge, based on which the ‘Torque’ is measured by multiplying the R-distance between the centre of pivotal point (strain gauge) with the varied opposing force.
Performance and emission analysis on diesel engine fuelled with neat pongamia biodiesel
Published in International Journal of Ambient Energy, 2022
T. Arul Nicholas, A. Venkatakrishna, Nivin Joy, Anish Mariadhas
The instrument used to measure the output power is dynamometer, which has a stationary rotor bounded by electromagnets and coupled with crankshaft by flexible coupling. The rotor’s rotary motion acts against the magnetic field generated by the electromagnet when supplied with sufficient electric current. This in turn creates resistance to rotor and thereby happens to apply load to engine. Hence, varying the current supplied to electromagnet can alter the load. The opposing force created on a dynamometer is measured by the change in strain gauge, based on which the ‘Torque’ is measured by multiplying the R-distance between the centre of pivotal point (strain gauge) with the varied opposing force.