Magnetic pole

A variable-speed drive is usually used on the feed and cross-belt drives to exercise control in separator operation, although the speed is not usually changed once the optimum operating condition is estabUshed. Feed rates and the selection of the number of magnetic poles are usually deterrnined by preliminary laboratory tests. The mineral types involved in the feed largely determine the number of poles selected. High intensity cross-belt separators are frequendy used in combination with induced-roU or electrostatic separators. 

The typic medium-sized squirrel-cage motor is designed to operate at 2 to 3 percent shp (97 to 98 percent of synchronous speed). The synchronous speed is determined by the power-system frequency and the stator-winding configuration. If the stator is wound to produce one north and one south magnetic pole, it is a two-pole motor there is always an even number of poles (2, 4, 6, 8, etc.). The synchronous speed is... 

MAGNETIC POLE COLD FORMING STEEL IMPACT EXTRUSION... 

Following the tolerance stack through the end assembly, the bobbin dimension of 22 mm from the outside face to the back face of the magnetic pole is analysed next. This characteristic dimension does not include the tolerance on the impact extruded pole. The pole is to be moulded into the bobbin and the pole face is considered to be part of a mould related dimension. The bobbin is injection moulded using 30% filled polybutylene terephthalate (PBT). The tolerance assigned to the bobbin dimension is 0.035 mm. 

Figure 7 SFM image of a thin-fiim read-write head showing magnetic poles (dark rectangles) recessed 200 A.

Consequently, Fludd attempted to prove that the world s poles are within man by allocating the directions of the compass to the body one should face east to pray with one s posterior to the west. The left-hand is then North, while the right-hand is South. The human body then comes into harmony with the magnetic poles. 

Fig. 2.3.1 A schematic diagram of GARField magnet pole pieces and the field pattern they produce together with a magnified sketch of the sample and sensor mounting showing the relative field, gradient and profile [/(r)] orientations.

In isotropic media 0 and S are related by = < , where the scalar parameter a is now referred to as the permittivity. In the international (SI) system it is given by s = erso. where o is the permittivity of vacuum (see Appendix fl) and e, is a dimensionless permittivity that characterizes the medium. Furthermore, according to Ohm s law the current is given by 7 = cr< , where a is the electrical conductivity. The relation V S3 = 0 is a mathematical statement of the observation that isolated magnetic poles do not exist. 

Magnetic fields Earth s magnetic poles (convection currents in the Earth s core)... 

Figure 2.2 Schematic view of the electron ionization source, a, Ion repeller h, anode c, acceleration and focalization plates N, S, magnet poles...

Magnet pole configurations, 15 453 Magnetrons, 16 519, 520 23 135-136 Magnetron sputtering, 24 731-732 Magnets... 

Form bottom magnetic pole by electroplating or sputtering... 

Deposition and patterning of the bottom magnetic pole follow. The pole is usually electroplated with a through-photoresist window frame mask to a thickness level of 2 to 4 fim. Note that whereas the magnetic pole is made into a pancake shape to increase the head efficiency, it is the narrow p>ole tip s dimension that determines the narrow track width. As stated, the widely used Co-based alloy magnetic poles are elec-trodeposited (wet process). Nanocrystalline FeN-based alloys are sputter-deposited in a vacuum chamber (dry process). 

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