Talk:Transformer/Archive 1

message: I think this is good candidtate for Featured article consideration, once we get it stable. Thoughts?--Light current 18:52, 12 January 2006 (UTC)
thread_title:  FAC 

message: I'm a little uncomfortable with 
: The energy converted to motion is one form of core loss.)
since some of that motion is not lost immediately, but stored as elastic compression.  I expect resonating at the mains frequency might ameliorate the loss (or might destroy the unit!) and an inspection by a power-systems EE might be valuable here. --Jerzy(t) 01:19, 2004 Mar 5 (UTC)
There is a whole lot about energy storage that could be included.
(I remember Professor Jerrold Zacharias pointing out that the trick
in a necessarily simplified introduction was not teaching anything
that would have to be unlearned later.)
There is not only mechanical energy storage, but magnetic and even
electrostatic energy storage to consider in a real transformer.
You are right, some of the stored energy is recovered, some is dissipated.
I am uncomfortable with leaving out any link to ideas related to
power factor, the issue that the current and voltage waveforms
may not be in phase. Maybe there is an article on reactive power to link.
Also of practical importance is that transformers sometimes have
non-sinusoidal waveforms applied. Harmonic distortion of nominally
sinusoidal power waveforms can be a big problem.
The imperfect relation between B and H is critical in practical
transformers. A power transformer can overheat and fail if there is a significant DC component to the current, for instance. And you can not arbitrarily change the voltages applied - sucessful use depends on more than the turns ratio.
It is possible to have significant unintentional transformers. Some examples:
* AC wiring practice always uses two wires, and they are always run together.
If you run the two wires in two separate metalic conduits, for instance, you
have created a simple transformer with a single turn secondary - the conduits, (and a single turn primary, the two wires) - the conduits can get quite hot.
* Twisted pair is often used in balanced circuits to minimize inductive coupling from ambient fields. However, if you have two circuits and you cross wire the twisted pairs, the circuit will look fine at DC, but transient signals in one circuit will transformer couple into the other circuit in a mysterious manner. The twisted pairs have become a transformer! The first time I encountered this wiring mistake it took a while to figure out.
::This sounds a bit like a transmission line transformer to me. Light current 14:41, 3 September 2005 (UTC)
replies: text: This is all good information, which I shall add to the article if I get time.  Unless you do it first, of course. ;-) -- Heron 22:14, 5 Mar 2004 (UTC)
thread_title: conversion to motion=loss?

message: I removed this line:
:"Antonio Pacinotti (1860)"
from the list of inventors, because I can find no evidence that Pacinotti had anything to do with transformers.  He did, however, invent a dynamo in 1860. Perhaps there was a mistranslation somewhere. -- Heron 20:06, 24 Jun 2004 (UTC)
thread_title:  Pacinotti 

message: I've added some content pertaining to power transformers, hysteresis, and fire-resistant cooling fluids. I'm not sure D'Arsonoval belongs here . I removed the pejorative description of PCBs as "toxic waste" since the people who invented PCB and thought it was perfect for the job didn't think of it as such.  --Wtshymanski 17:21, 11 Dec 2004 (UTC)
thread_title: Power transformers

message: "step across" transformer appears to be a Wikipedia artifact only and is not actually used in the industry.  I've been unable to locate a reference to that term either in my local library or on the Web, barring a bunch of quotes from Wikipedia itself.  I've deleted this Wikifiction. 
--Wtshymanski 20:51, 28 Jan 2005 (UTC)
thread_title: Step-across transformers

message: Does any one know how these work or something like that? Is this just three seperate transformers? Thanks
:No, true polyphase transformers have three sets of windings that share a single set of core laminations. The usual arrangement is to have a core that is shaped like the letter "E" but with the open end closed. One set of coils is placed around each of the "legs" of the E.
I think this works out nicely because the phase relationship means that some of the magnetism from one set of coils is opposed by magnetism from other sets of coils, allowing a proportionally-smaller core assembly than would be required by three completely-separate transformers.
Here are some images from out on the web click..., click..., or click. The second and third clearly show the wiring of the HT side of the transformer.
:Atlant 14:53, 15 Apr 2005 (UTC)
replies: text: This sounds right to me. I think that its obviously  far more economical to make a 3ph transformer on a 3 limb core than to have 3 separate transformers. I am pretty sure that the total max flux density in the core due to 3 ph is probably not much greater than it would be for single ph. due to the 120 deg ph diff between consec phases. Anyway, the total flux density in a transformer is zero (apart from magnetising flux )if the secondary is loaded properly. Light current 00:35, 3 September 2005 (UTC)
thread_title:  Poly Phase Transformer