Talk:Commutator (electric)

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[edit] About the rating

Although there is decent amount of text there is a lot of redundancy so I think this article currently still qualifies as a stub. Specifically the last paragraph of the intro and the second paragraph of Composition of a Commutator are almost identical, but even much of the remaining text is largely a restatement of this same information on how they are constructed. More coverage should also be given to the longevity of the device, its history (both development and use), and something should be said about the efficiency of the device. -AndrewBuck 15:57, 27 March 2007 (UTC)

I rewrote most of the article partially addressing the issues mentioned above but I still think further attention is required. -AndrewBuck 14:14, 28 March 2007 (UTC)

Needs still more work. And references. I was going to say a commutator is a required feature of direct-current machines but I suppose there are homopolar machines. --Wtshymanski 02:22, 5 August 2007 (UTC)

[edit] Intro

"A commutator is an electrical switch that periodically reverses the current in an electric motor or electrical generator."

no:

  • a motor/commutator based synchronous rectifier does not reverse the current - in fact it has no effect on the current in the motor at all.
  • a dc generator uses a commutator to avoid reversal of current, though its more complex of course.


"By reversing the current in the moving coil of a motor's armature, a steady rotating force torque is produced."

no. This would only be true if all the following were true (and they cant be):

  • communtator timing were perfect, with no gap and no overlap
  • Motor current remained absolutely constant, which is impossible since windings have inductance
  • Magnetic circuits were arranged to ensure constant torque despite changing rotational position.

Tabby (talk) 02:12, 22 December 2007 (UTC)

[edit] Blinking GIF animation replacement

Not only is that flashing, pulsating, blinking GIF animation visually annoying to look at, but it is also fundamentally incorrect since it has a dead spot in the rotation, as the brushes cross the insulated midsection.

The simplest practical commutator has at least three segments, and the brushes must normally span two segments and short at least one winding, in order to maintain current flow in the other two windings.

I am going to see how hard it is to create a correct 3-segment animation, and with less annoying flickering. DMahalko (talk) 14:50, 19 May 2008 (UTC)