Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Power transformer ratings and cross-sectional area.
Power transformer ratings and cross-sectional area.
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 29th January 2013, 07:13 PM   #1
costasx is offline costasx  United Kingdom
diyAudio Member
 
Join Date: May 2012
Location: at home
Default Power transformer ratings and cross-sectional area.

I think there is an empirical formula that relates the power transformer's power ratings to it's cross-sectional area in cm^2, could someone please remind me that formula?

It's an empirical and approximative one, not exact.
  Reply With Quote
Old 29th January 2013, 07:28 PM   #2
oz7aff is offline oz7aff  Denmark
diyAudio Member
 
oz7aff's Avatar
 
Join Date: May 2012
Location: Denmark
There might be some thing of the subject here:

http://www.sandcastle.dk/artikler/Po...ansformers.pdf
__________________
Regards Max
  Reply With Quote
Old 29th January 2013, 07:35 PM   #3
costasx is offline costasx  United Kingdom
diyAudio Member
 
Join Date: May 2012
Location: at home
Thank you oz7aff.
What is the book?
  Reply With Quote
Old 29th January 2013, 07:44 PM   #4
oz7aff is offline oz7aff  Denmark
diyAudio Member
 
oz7aff's Avatar
 
Join Date: May 2012
Location: Denmark
Coil Design and Construction Manual

Book. No. 160

B. B. Babani

I.S.B.N. 0 85934 050 3

First Published 1960

I think you can download the whole book here:

Coil Design & Construction Manual : B.B. Babani : Free Download & Streaming : Internet Archive
__________________
Regards Max
  Reply With Quote
Old 29th January 2013, 07:48 PM   #5
costasx is offline costasx  United Kingdom
diyAudio Member
 
Join Date: May 2012
Location: at home
It's great, thank you.
  Reply With Quote
Old 30th January 2013, 10:12 PM   #6
sawreyrw is offline sawreyrw  United States
diyAudio Member
 
Join Date: Apr 2006
Location: Minnesota
The core power handling capability is a function of the product of the core cross sectional area and the winding area. Google for something like core area product.
  Reply With Quote
Old 31st January 2013, 07:51 AM   #7
Elvee is offline Elvee  Belgium
diyAudio Member
 
Elvee's Avatar
 
Join Date: Sep 2006
Quote:
Originally Posted by costasx View Post
I think there is an empirical formula that relates the power transformer's power ratings to it's cross-sectional area in cm^2, could someone please remind me that formula?

It's an empirical and approximative one, not exact.
The power in VA of a conventional 50Hz transformer can be crudely estimated by squaring the cross-section expressed in cm˛. Give or take 25%, depending on the quality of the iron, filling ratio, margins, etc
__________________
. .Circlophone your life !!!! . .
♫♪ My little cheap CirclophoneŠ ♫♪
  Reply With Quote
Old 31st January 2013, 10:53 AM   #8
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
A = core area in sq in or a = core area in sq cm
VA = 31 * A^2 for flux @ 1T
VA = 0.75 * a^2 for flux @ 1T
If you choose a different flux, you just change the VA in direct proportion.
eg.
core 3cm * 4cm
a= 12 sq cm
Flux = 0.7T
VA ~ 0.7 * 0.75 * [3*4]^2 = 75VA
__________________
regards Andrew T.
  Reply With Quote
Old 31st January 2013, 11:51 AM   #9
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
The numbers in my previous post are for 50Hz.
Slightly more VA is obtained with 60Hz.
__________________
regards Andrew T.
  Reply With Quote
Old 3rd February 2013, 07:25 PM   #10
Yugo is offline Yugo
diyAudio Member
 
Yugo's Avatar
 
Join Date: Jun 2004
Location: Ex-Ex Yu,very far from Ei factory
Quote:
Originally Posted by AndrewT View Post
A = core area in sq in or a = core area in sq cm
VA = 31 * A^2 for flux @ 1T
VA = 0.75 * a^2 for flux @ 1T
If you choose a different flux, you just change the VA in direct proportion.
eg.
core 3cm * 4cm
a= 12 sq cm
Flux = 0.7T
VA ~ 0.7 * 0.75 * [3*4]^2 = 75VA
Andy,
I suppose you are meaning for so called wasteless cores.Are these formulas valid for c-cores or let's say double c-cores.I think that the size of window and the length of the core play a key role also,considering the constant flux.Are there any other formulas particularly aimed for c-cores regarding their different shapes?

Regards,
Yugovitz
__________________
Bird lives!
  Reply With Quote

Reply


Power transformer ratings and cross-sectional area.Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Determining the core cross sectional area, Afe, for SE OPT Tyimo Tubes / Valves 11 17th September 2012 09:12 PM
cross sectional area shapes gafhenderson Full Range 5 3rd April 2012 05:23 AM
confused on power transformer ratings nightanole Tubes / Valves 21 26th August 2010 09:08 PM
Transmission line cross-sectional area question h@kan Full Range 11 26th October 2009 12:18 PM
Power supply transformer ratings deskmate88 Chip Amps 4 29th January 2004 06:29 AM


New To Site? Need Help?

All times are GMT. The time now is 10:57 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki