Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: budd3 on 19/02/2012 05:00:55
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How strong can scientist make magnets or electromagnets and could scientist use the energy from magnets for transportation or even as an energy source?
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It is not possible to use magnetic fields as an efficient mechanism for storing energy
Permanent magnets require considerable quantities of energy to change their magnetisation and cannot be used for energy storage in this way.
Normal electromagnets require a continuous supply of energy to overcome electrical resistance and are therefore not useable as a magnetic energy store.
superconducting magnets can be used to store quite large quantities of energy but the limit is set by the maximum field the superconductor will take before superconductivity breaks down. However all superconducting materials require to be kept very cold. The colder the better because the strength of the field they will take goes down as the temperature rises. The best ones at liquid helium temperatures. This requires thermal insulation and a supply of energy to keep the helium liquified. It also makes them heavy and difficult to move.
The best use for magnets as an energy source is their use in electrical generators using the movement of magnets and not as energy storage in their own right.
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The present limits seem to be about 25T for continously operating magnets which comsume megawatts of power and 100T for the reusable pulsed variety.
If you are prepared to destroy your pulsed magnet in one go fields of up to at least 1800T have been achieved, this is of course a developing area of research and there is competition between various groups to make the strongest.
If my arithmetic is correct magnetic fields of 285T contain as much energy for a given volume as Dynamite
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How strong can scientist make magnets or electromagnets and could scientist use the energy from magnets for transportation or even as an energy source?
So if we can't use magnetic energy as an energy source can we still use it for transportaion vehicles. Maybe using electrical energy to magnetic energy to kinetic energy?
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How strong can scientist make magnets or electromagnets and could scientist use the energy from magnets for transportation or even as an energy source?
So if we can't use magnetic energy as an energy source can we still use it for transportaion vehicles. Maybe using electrical energy to magnetic energy to kinetic energy?
Yes, we can!
That's exactly what electric motors do.
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I would have thought a 1000T magnet would have lead to ACME Corporation type effects in the vicinity of the lab testing it!
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Maglev trains (http://en.wikipedia.org/wiki/Maglev) utilize a special case of a linear magnet motor. However, as with all electric/magnetic motors, they require a system of rapidly alternating polarity.
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Maglev trains (http://en.wikipedia.org/wiki/Maglev) utilize a special case of a linear magnet motor. However, as with all electric/magnetic motors, they require a system of rapidly alternating polarity.
Unless, of course, it is a DC motor :)
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Maglev trains (http://en.wikipedia.org/wiki/Maglev) utilize a special case of a linear magnet motor. However, as with all electric/magnetic motors, they require a system of rapidly alternating polarity.
Unless, of course, it is a DC motor :)
What exactly is a DC motor?
Doesn't it also run on AC?
Generally using DC (or Permanent magnets) to supply a fixed polarity to the field coils, and brushes to provide alternating current/polarity to the armature.
Or visa-versa, providing fixed polarity to armature, and some switching technology to vary the polarity of the field coils.
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What exactly is a DC motor?
Doesn't it also run on AC?
Generally using DC (or Permanent magnets) to supply a fixed polarity to the field coils, and brushes to provide alternating current/polarity to the armature.
Or visa-versa, providing fixed polarity to armature, and some switching technology to vary the polarity of the field coils.
A DC motor is any motor that does not require an AC supply. They generally include a commutator which maintains the correct relationship between the armature and stator fields so that a torque is always tending to rotate the armature in a particular direction.
If the stator field is produced by a permanent magnet, the motor can only operate on DC, but if the stator field is produced electromagnetically from the supply current, the motor will run on AC or DC, and it is, essentially, frequency independent, unlike most other AC motors who's rotational speeds are frequency dependent.