Transformer secondary calculations. - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies

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 16th August 2014, 01:41 AM   #1
diyAudio Member
 
Bixbacon's Avatar
 
Join Date: Apr 2012
Location: Australia
Default Transformer secondary calculations.

Hi everyone, I have salvaged an old chassis complete with transformer. I have attached pics of the ac voltages. I plan on caseing my Pass B1 buffer which requires 18 - 24 DC. The buffer has 2 x 15000uf 35 volt filter caps and the bridge rectifier is a d5sba20.
My knowledge of equations is limited, but this is a great opportunity for me to learn. Help with this is much appreciated.
__________________
Its not worth saying, if it's not heard wright.
  Reply With Quote
Old 16th August 2014, 01:46 AM   #2
diyAudio Member
 
Bixbacon's Avatar
 
Join Date: Apr 2012
Location: Australia
Default Woops

Here is pic,
Attached Images
File Type: jpg image.jpg (213.8 KB, 86 views)
__________________
Its not worth saying, if it's not heard wright.
  Reply With Quote
Old 16th August 2014, 01:49 AM   #3
diyAudio Member
 
Bixbacon's Avatar
 
Join Date: Apr 2012
Location: Australia
Default Can't upload more than 1 pic

Blue - blue
Attached Images
File Type: jpg image.jpg (220.6 KB, 77 views)
__________________
Its not worth saying, if it's not heard wright.
  Reply With Quote
Old 16th August 2014, 01:53 AM   #4
diyAudio Member
 
Bixbacon's Avatar
 
Join Date: Apr 2012
Location: Australia
Ok so
Blue - blue = 6.36
Org - org = 23.28
Yel - yel = 11.73
Attached Images
File Type: jpg image.jpg (196.0 KB, 75 views)
__________________
Its not worth saying, if it's not heard wright.
  Reply With Quote
Old 16th August 2014, 06:24 AM   #5
diyAudio Member
 
Bixbacon's Avatar
 
Join Date: Apr 2012
Location: Australia
Is this a silly question?
__________________
Its not worth saying, if it's not heard wright.
  Reply With Quote
Old 16th August 2014, 07:04 AM   #6
Elvee is offline Elvee  Belgium
diyAudio Member
 
Elvee's Avatar
 
Join Date: Sep 2006
Quote:
Originally Posted by Bixbacon View Post
Is this a silly question?
No, but you may be a bit too impatient.

You also need to know the current capacity of each winding. The simplest method is to measure the gauge of each wire, but it requires that the output wires are directly the enameled copper, otherwise you'll have to resort to another technique, involving the measurement of the windings resistance.
__________________
. .Circlophone your life !!!! . .
♫♪ My little cheap Circlophone© ♫♪
  Reply With Quote
Old 16th August 2014, 07:32 AM   #7
diyAudio Member
 
Bixbacon's Avatar
 
Join Date: Apr 2012
Location: Australia
Thanks Elvee, just nervous. I measured R between yel, org and blu combinations then divided voltages by R: Currents = Yellow 3.3 A, Org 3 A, Blu 4.5 A.
__________________
Its not worth saying, if it's not heard wright.
  Reply With Quote
Old 16th August 2014, 08:11 AM   #8
Elvee is offline Elvee  Belgium
diyAudio Member
 
Elvee's Avatar
 
Join Date: Sep 2006
Quote:
Originally Posted by Bixbacon View Post
Thanks Elvee, just nervous. I measured R between yel, org and blu combinations then divided voltages by R: Currents = Yellow 3.3 A, Org 3 A, Blu 4.5 A.
That looks impossible, unless it is a very low power PSU.

You have to measure using 4 wire technique, with a test current of 100mA or 1A
__________________
. .Circlophone your life !!!! . .
♫♪ My little cheap Circlophone© ♫♪
  Reply With Quote
Old 16th August 2014, 08:32 AM   #9
diyAudio Member
 
Bixbacon's Avatar
 
Join Date: Apr 2012
Location: Australia
Im confused, The transformer is from a Akai CX 210 tape deck, pic below.
Is there a secondary combination I can try? Thanks for your patience.
Attached Images
File Type: jpg image.jpg (226.3 KB, 53 views)
__________________
Its not worth saying, if it's not heard wright.
  Reply With Quote
Old 16th August 2014, 09:24 AM   #10
diyAudio Member
 
Bixbacon's Avatar
 
Join Date: Apr 2012
Location: Australia
Ok, so I have done some reading and come up with,

I hooked up one pair of the secondary wires together, organge and blue, 23.3 volts + 6.36 volts. The measured the AC voltage at the free ends. This gave me 17 volts.

For rectifier,
If multiply 17 volts by 1.4 I get 23.8 volts, - 1.4 = 22.4volts

Does this sound about wright?
__________________
Its not worth saying, if it's not heard wright.
  Reply With Quote

Reply


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Transformer calculations Frosteh Power Supplies 3 26th May 2011 05:16 PM
Calculations for MC Transformer Binaural Analogue Source 2 22nd April 2009 07:14 AM
help with transformer secondary jarthel Power Supplies 34 8th July 2006 01:01 AM
Calculations for new Power transformer kskr Tubes / Valves 3 3rd May 2006 09:29 AM


New To Site? Need Help?

All times are GMT. The time now is 10:53 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2