The purpose of the shading coil in some appliance motors is to?
446286
This type of ac motor uses the shading coil (the shaded pole or poles) to change the phase shift of the magnetic flux or field.The rotor is usually a laminated cylinder.Whe the induced currents in the rotor are out-of-phase a torque is produced on the rotor.The electric meter on a house uses this type , and the rotor is the aluminum disc that rotates.It can be shown that when ther is a phase shift caused by the closed copper turn(s) that a torque is produced.
1514
you must use insulated wire or you will effectivly just short out your power source.  most modern electro-magnets use wire that is insulated with a thin coating of a special varnish.  this allows more winding in a given space.  varnish insulated wire is available from nearly any electronics store or catalog or from any business that rewinds electric motors
178800
To make a motor you need 28 guage copper wire that will have a dark tinted laquer on it. You cannot see it except it is usually darker than copper. In other words you can sand it off when you need to solder it or make a connection. You can buy this wire at radio shack I think.
1068932
To reduce strain on the electrical system when starting the motor (needs that initial "kick" to get it going and would overload most systems).
124472
In HVAC(heating, ventilation, and air conditioning) a condensing coil is a part of an air conditioning system. \n\nLiquid refrigerant is passed through an evaporator coil where it is turned to a gas and absorbs heat. It is then compreesd into a liquid and passed through a condenser coil where it expels heat. It returns then to the evaporator coil to continue the process. \nThe properties of pressurizing and depressurizing of refrigerants makes this entire process work.\n\n\nAnother form of condeser coil is part of a "retort". heated gases are passed through coils and as the gases cool in that coil, compounds condense (turn to liquid) and can be recovered or further processed. The image of an old whiskey still comes to mind, the copper coil on top is the condenser where the alcohol is collected.
914136
My guess is that they are nothing more than an injection molded fan (Thermoelastomer blades with a rigid plastic overmold) pressed on to the end of a small DC motor.  If it is coming from China, don't expect great quality.  Chances are it is only designed to work a few times.  The switch contacts are probably bits of brass that touch eachother when you push the button.
17874
Tesla invented many devices.  I assume you mean the "Tesla coils".  The Tesla coils can produce currents or discharges of very high frequency and voltage.  They are useful for classroom demonstration, theater and movie special-effects, and product/technology safety testing.  They act like high-frequency, air-core transformers.
713460
from the electric scouce to the motor electric current (flow of electrons in one direction),\nin the motor\n\nelectric current interfears with magnetic flux thus pushing the rotator away since it is fixed to one point it rotates trying to move away(like the way like poles repell) thus the energy changes from electric to mechanical through elecromagnetic.\n\nthen when the fan rotates (notice that the propellers are curved so as to scoop air molecues pushing them forward creating a kind of vaccum that is imediatley filled then the same procces is repeated creating wind not concention ) \nif it were convention it would require change of temperature and this only applies the principle of pushing air (like a pedal pushing water only that it is air the propellers are pushing)
154800
From what I know about permanent magnets, the heat is the killer when you get near the transistion temperature of the material.  When you do this, the magnetic domains become randomly aligned again and the pole force gets reduced.  If you keep heating it, you can totally demagnatize the material.  In fact, during the manufacturing process, the material is heated very hot under a very strong magnetic field and cooled, allowing the aligned domains to be "frozen" making a high force pole.  \n\nSo in motor design, the aerodynamics of the rotor, the eddy currents generated while running, and the torque loads, will all contribute to heating the magnets.  If you can master the thermal design, you can make very powerful motors.
1002680
When a magnet is passed through the centre of a coil of wire an electric current is produced in the wire. The energy comes from the movement of the magnet. Kinetic energy is converted into electrical energy and this is how electricity is generated in a generator. The reverse can also happen. Passing electricity through the electric coil in your cars starter motor will cause the magnet inside to move. Hence electrical energy is converted to kinetic energy and this energy turns the crankshaft of your car to get it started.
275517
- A DC brushless electromotor is mainly a step-motor with a rotor made out of permanent magnet, and a stator made out of coils (mostly 4 coils, but it depends on the type of step-motor). As this is a step-motor, it needs some kind of regulator, which is made on a little electronic board. So... a DC brushless motor is made out of 3 things: \n\n1 Electronic Circuit Board \n2 Coils \n3 Permanent Magnet \n\n- Electronic Circuit Board and Coils: \n\n- This part is doing the trick - rotating the permanent magnet. There are in most every case only 4 coils in a normal fan, grouped as 2+2. The first group (let's call them the North-South group) is connected to one electrical circuit on the electronic board. And the second - East-West - is connected to the other electrical circuit. \n\n- On the electronic circuit board is located one small device that is most responsible for this trick. It is called Hall-probe (or Hall-sonde), and its location is just under the permanent magnet. \n\n- It's used to detect the south pole of the permanent magnet. The Hall-probe regulates two different electric circuits driven by two transistors, and depending on the pole it detects, it drives the proper circuit. With this type of regulation, it is possible to create a rotating magnetic field, and rotate the permanent maget located around the coils. \n\n- A permanent magnet has two-poles - North and South. Let's look what happens when the fan is powered. \n\n- Depending on the location of the south pole, Hall-probe drives one of the circuits. So, let's say that Hall-probe is sensing the south pole. It drives one of the circuits (let's say north-south circuit). \n\n- When the north and south coils are powered, they produce the magnetic field. This field is of the same direction in both coils, but... :) the Magnet hasn't got the same direction of the magnetic field in both poles. It looks like one coil is pushing the north pole away, and on the other hand, the second coil is pulling the south pole to itself. \n\n- Now, when the magnet is moved, the south pole goes away from the Hall-probe, and as it isn't sensing it anymore, it drives the second transistor (second circuit). With that, east-west coils are turning on, doing the same job as north-south coils did before. \n\n- So, basically the trick was to produce the rotating magnetic field. And it was done very cleverly! :) As coils aren't made as a moving part, it is obvious that there are no brushes, so that's the part where the name came from - 'DC brushless'. \n\n- Permanent Magnet: \n\n- This is the mostly known part of the electromotor. I think that I don't need to explain much about it. It has two poles - north and south, and using the external magnetic field it is possible to move the magnet around. In a fan, the magnet is circuit-shaped and it rotatrd around its axis. \n-------------
23227
It uses a permanent magnet which is rotated by a crank. The spinning magnet is positioned so that its north and south poles passed by a piece of iron wrapped with wire. It was discovered that the spinning magnet produced a pulse of current in the wire each time a pole passed the coil. Furthermore, the north and south poles of the magnet induce currents in opposite directions. By adding a commutator, it is possible to convert the alternating current to direct current.
682407
This is done to link the flux produced in one coil with the other one.Each time the current reverses in the first coil the magnetic flux also reverses which if properly linked with the second coil will induce an emf in the second one as the induced emf will produce a magnetic field which opposes the change in the magnetic field due to the first coil.Iron has a high value of relative magnetic permeability.Thus most of the magnetic flux due to the first coil will pass through it.And if a second coil is wound over it the changing flux will pass through that one too.
352019
http://en.wikipedia.org/wiki/Filament_winding
219408
A solenoid is an electromechanical device that will generate a limited motion when it is energized.  It consists of an electromagnet (coil of wire) and pin/bar/plate that is ferrous and can be attracted by magnetic force.  The pin is then connected to whatever device that needs to be acted upon mechanically and usually has a spring on it to return it back to its original position when the solenoid is de-energized.\n\nSolenoids are usually found controlling valves, but can be used elsewhere as well.  Perhaps the most common solenoid that you will come in contact with is those used to actuate the power door locks in a car.  That is a dual-acting solenoid in which there are two coils, one to unlock the door and another to lock the door.
657419
if you move the magnetic source through a coil you can measure how much current you get on both end of the wire with a meter. when the magnet is moved throught the coil the it magnet has a negative or positive attraction or opposing force that will push current through.  It will create an inductive force through making current and if there is a capacitor the store that current the capacitor can be used as a power source.
849597
Both inductors and capacitors store energy, in the form of magnetic or electric fields, respectively, so they have some possibility of discharging that energy in a dangerous way. Shorting out a large capacitor, for example, would produce a large current. Overheating an inductor (too much current) might cause the coil to fail, and then the magnetic field decay would produce a voltage spike I think. I would assume the risks with small components are quite small.