Re: Toroid for mains conversion?

On Fri, 03 Jul 2009 13:41:48 +1000, Phil Allison wrote:

"Dorothy with the Red Shoes on"...
"Phil Allison"


I saw a site once that said toroids were much more efficient

** False.
The percentage efficiency of similar rated E-cores and toroiodals is
the same.


They are less leaky.

** ??????????


It stands to reason that any difference, even if too small to consider
major, would be in favor of the toroid.

** For the same VA rating, percentage efficiency ( under load) can go
either way, by small margins.

The subject is MAINS power toroidals BTW.

And toroids are a pain in the ass to wind. Even if you have a machine
doing it, it's still a pain in the ass because the machines require a
much greater degree of care and feeding than a simple wire winding lathe
putting turns on a bobbin. (You can figure this out on your own if you
consider what the machine has to do. I used to know a guy who had to
maintain both types, and the toroid-winding machines were _always_
broken).

So: you get an itty bitty bit more efficiency -- maybe -- and you have to
deal with much more finicky machines on your production line.

This probably explains why there are a few toroidal mains power
transformers out there, but not a whole lot of them.

--
www.wescottdesign.com
.

Relevant Pages

  • Re: Toroid for mains conversion?
    ... The percentage efficiency of similar rated E-cores and toroiodals is ... would be in favor of the toroid. ... and the toroid-winding machines were _always_ ... used ferrite pot core transformers for audio... ...
    (sci.electronics.design)
  • Re: Toroid for mains conversion?
    ... The percentage efficiency of similar rated E-cores and toroiodals is ... would be in favor of the toroid. ... and the toroid-winding machines were _always_ ... Isn't the object of a torroidal transformer greater isolation and less ...
    (sci.electronics.design)
  • Re: Can you learn computer science from a school?
    ... But this of course is just arguing my original point, that the real-world constraints of real-world machines necessarily influence algorithm design, and so Computer Science is concerned with these real-world constraints as well. ... First, "efficiently" computable isn't quite the right word, because efficiency typically goes to the resources required, compared to some ideal, rather than "can I run this computation in less than the expected life of my computing system?". ...
    (comp.lang.lisp)
  • Re: brain thoughts
    ... machines. ... If efficiency was a problem, then yes, we might not be able to equal _full_ ... human behavior with computer parts because it might take more power than we ... response to the stimulus signals. ...
    (comp.ai.philosophy)
  • Re: Toroid for mains conversion?
    ... "Phil Allison" ... The percentage efficiency of similar rated E-cores and toroiodals is ... would be in favor of the toroid. ... Less weight, low profile, very low external field, very low off load ...
    (sci.electronics.design)