|WikiProject Engineering||(Rated C-class)|
|WikiProject Electrical engineering||(Rated C-class)|
I'm taking over this redirect to stator because field coils are not always on the stator so it's not really correct as a redirect to there.
I don't really have time to work on this article right now, but this is going to get some major expansion, with text and illustrations of series wound, shunt-wound, and compound-wound field coils.
I have a two concerns about the opening sentence:
- An electrodynamic loudspeaker is listed, but the article only talks about rotating devices. Except for one reference to stator, only DC devices are dicsussed.
- What does "magnetic field component" mean? Isn't the iron also a magnetic field component?
Can anyone suggest a way to improve the first sentence?
- It's a poor first sentence, "A field coil is the magnetic field component of an alternator, generator, dynamo, motor, rotary converter, electrodynamic loudspeaker or similar machinery." However, "A field coil conducts electrical current around a magnetic pole in a machine with a rotating armature, such as an alternator, generator, dynamo, motor, or rotary converter. This article does not discuss field coils in other devices, such as an electrodynamic loudspeaker. " is not an improvement.
- Field coils do not "conduct current around a magnetic pole". The implied causality would be wrong: magnetic fields arise as a result of this current.
- Secondly field coils make fields. They do this anywhere, whether there is rotation or not. It would change the scope of the article to exclude some devices in the lead, and that's something we should only do if it's best for the article to represent that narrower scope, not just because we haven't yet written that section of the article. This applies to field coil loudspeaker (which are obscure and shouldn't be linked as a bare link, or they'll be confused with the far more common dynamic loudspeaker). It also applies to machines such as mass spectrometers and electromagnetic clutches that use fields from currents in coils, but that aren't motors or generators. Andy Dingley (talk) 22:17, 25 August 2011 (UTC)
- Well at least we agree that it is a poor first sentence. Until the rest of the article is written, the lead does not agree with the content. Should we add a stub box? How do suggest improving the article? I will think about the article for a while, and will try again, if I have an idea.
- I shading the iron in the first motor. How do you like it? Should I do the same with the others?Wikfr (talk) 22:50, 25 August 2011 (UTC)
- I came upon the article Coil, with a section called Electromagnetic coils. It has many examples, but does not list "field coil". Now we need a good way to destinguish a field coil from an electromagnetic coil. We could start the article by saying "A field coil is an electormagnetic coil that... Any suggestions?Wikfr (talk) 01:52, 26 August 2011 (UTC)
Field/armature vs rotor/stator.
I've been going through articles and trying to clean up confusion about the difference between field/armature and rotor/stator. This article had some text indicating that the field of a motor is always on the stator, and the armature is always the rotor. Then, for generators, for generators, "Accordingly the field is mounted on the rotor and supplied through slip rings.". Actually, both geometries are possible for both types of machines. Big generators generally have the armature on the stator, so the heavy output currents don't go through slip rings. (There's a variant on this where the field windings are on the rotor, and they're energized from a second smaller generator on the same shaft fed through diodes, all on the rotor. This eliminates all slip rings and brushes, the most troublesome components.) Smaller generators can go either way. Permanent magnet motors come in both rotor magnet  and field magnet forms. "Brushless DC" motors are rotor magnet devices, with no electrical connection to the rotor. Most small toy motors are stator magnet motors. John Nagle (talk) 06:34, 3 January 2016 (UTC)