[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TCML] Self ballasting transformers



I think that most small power transformers have no real current limiting,  
other than core saturation. Many contain a fusible link inside that prevents  
overheating, but it's not replaceable. Others may be impedance protected as you  
say, by using many turns of small wire to yield enough impedance to  prevent 
overheating even when overloaded.
 
Tony Greer

In a message dated 11/9/2008 8:33:34 A.M. Central  Standard Time, 
bsneath@xxxxxxxxxxxxxxxx writes:

hi all,

I have a question regarding the self-current-limitting  transformers that are 
used in most old appliances. 
It would seem that they  have no shunts at all, and the only way they ballast 
themselves is with a large  number of primary turns.
To clarify, the transformers i'm talking about are  those little <100watt 
ones that powered stuff like DVD players etc. before  switching psu's took 
over. 
But how does it work?
Another thing, when  i put a new secondry on one such xfrmr after extending 
the core (by using 2 E  sections back to back instead of the usual E I 
construction), the current  limiting no longer worked as well and i could 
draw more power out of it than it  was rated for.
so, how do these xfrmrs self-limit, and how does the core  extension affect 
it?
 
**************AOL Search: Your one stop for directions, recipes and all other 
Holiday needs. Search Now. 
(http://pr.atwola.com/promoclk/100000075x1212792382x1200798498/aol?redir=http://searchblog.aol.com/2008/11/04/happy-holidays-from
-aol-search/?ncid=emlcntussear00000001)
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla