Transformer wiring - 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 4th March 2012, 02:40 PM   #1
diyAudio Member
 
Calamaro's Avatar
 
Join Date: Mar 2008
Location: Twenty Thousand Leagues Under the Sea
Default Transformer wiring

Just scavanged this transformer from an old tube radio and I don't understand its wiring.

Primary:
these were connected to voltage selector:
blue 220v
green 160v
black 145v
red 125 v
yellow 110v

but what about brown and 2 white?

Secondary:
I've checked when still working in the device
2 red 400v
2 white 6v
what about black?

I wonder if there is some kind of colour code (I read red for anode and white for heaters) or how calculate unknow values...
Attached Images
File Type: jpg IMGP2371.jpg (156.5 KB, 378 views)
File Type: jpg IMGP2369.jpg (142.5 KB, 363 views)
File Type: jpg IMGP2372.jpg (159.4 KB, 353 views)
  Reply With Quote
Old 4th March 2012, 04:05 PM   #2
RJM1 is offline RJM1  United States
diyAudio Member
 
Join Date: Jan 2010
Location: Titusville, Fl.
The black is probably the center tap for the red wires and was connected to ground. You can verify this with an ohm meter, the resistance between the black and either red wire should be half of the resistance of that between the two red wires.
  Reply With Quote
Old 4th March 2012, 04:10 PM   #3
diyAudio Member
 
Calamaro's Avatar
 
Join Date: Mar 2008
Location: Twenty Thousand Leagues Under the Sea
Quote:
Originally Posted by RJM1 View Post
The black is probably the center tap for the red wires and was connected to ground. You can verify this with an ohm meter, the resistance between the black and either red wire should be half of the resistance of that between the two red wires.
I measured 300ohm and 164 ohm so it is 400-0-400.
Thanks! Any idea about the other wires?

Last edited by Calamaro; 4th March 2012 at 04:29 PM.
  Reply With Quote
Old 4th March 2012, 10:05 PM   #4
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Are all the "primary" wires on the same winding?

Are all the secondary wires on the same winding?
__________________
regards Andrew T.
  Reply With Quote
Old 4th March 2012, 10:34 PM   #5
diyAudio Member
 
Calamaro's Avatar
 
Join Date: Mar 2008
Location: Twenty Thousand Leagues Under the Sea
Quote:
Originally Posted by AndrewT View Post
Are all the "primary" wires on the same winding?

Are all the secondary wires on the same winding?
I really don't know
How can I check? Are you suggesting that white unknow wires are another 6,3v secondary?

And: If blue wire is one of primary wires for 220v, which one is the other one?

Last edited by Calamaro; 4th March 2012 at 10:36 PM.
  Reply With Quote
Old 5th March 2012, 09:34 AM   #6
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
BE VERY CAREFUL !
If there is anything in the following paragraphs that is not clear then ask again before you guess and kill yourself.

Insert each end into a separate terminal of an insulated terminal block.
The screws will ensure a reliable contact through the enamel insulation.
Use an ohm-meter to check check for continuity from all the ends to all the others.
Label each continuous set. They are one winding.
Each winding could have more than 2 ends. Sometimes an adjustment tap (or taps) just a few %, more or less, sometimes a tap at the centre (50% to either side).

Then measure the resistance of each part of the winding from tap to tap.
This will let you identify the "ends" of the windings and the intermediate tapping points.

Now select the longest "primary" tappings. Power up via a bulb tester.

Measure the voltage at each of the secondary windings and at any intermediate taps.
__________________
regards Andrew T.

Last edited by AndrewT; 5th March 2012 at 09:37 AM.
  Reply With Quote
Old 5th March 2012, 10:10 AM   #7
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
The whites could be a separate heater winding for a rectifier, either 6.3V or 5V (depending on the age of the set). Newer rectifiers tend to have an isolated heater, just like other valves, but a separate heater winding can still help with valve lifetime.
  Reply With Quote
Old 5th March 2012, 05:19 PM   #8
diyAudio Member
 
Calamaro's Avatar
 
Join Date: Mar 2008
Location: Twenty Thousand Leagues Under the Sea
Quote:
Originally Posted by AndrewT View Post
Use an ohm-meter to check check for continuity from all the ends to all the others.
Label each continuous set. They are one winding.
Each winding could have more than 2 ends. Sometimes an adjustment tap (or taps) just a few %, more or less, sometimes a tap at the centre (50% to either side).

Then measure the resistance of each part of the winding from tap to tap.
This will let you identify the "ends" of the windings and the intermediate tapping points.

Now select the longest "primary" tappings. Power up via a bulb tester.

Measure the voltage at each of the secondary windings and at any intermediate taps.
I'v e checked for continuity.
"Primary" wires: continuity between
-green
-black
-red
-yellow
-brown

no blue and no 2 white
continuity between 2 white

"seconday" wires:
continuity between 2 white
2 red wires don't have continuity at all
same for black wire

Hope this means something to you

Some resistance values:

between:
brown and yellow 9
brown and red 12
brown and black 16
brown and green 21
brown and blue 59

between 2 white "primary" side 5
between 2 white "secondary" side 5
between 2 red "secondary" side 314
between one red and black 164

Once again I hope this means something to you
Attached Images
File Type: jpg IMGP2371.jpg (156.5 KB, 278 views)
File Type: jpg IMGP2372.jpg (159.4 KB, 267 views)

Last edited by Calamaro; 5th March 2012 at 05:23 PM.
  Reply With Quote
Old 7th March 2012, 09:17 PM   #9
diyAudio Member
 
Calamaro's Avatar
 
Join Date: Mar 2008
Location: Twenty Thousand Leagues Under the Sea
Default Fundamental question

Fundamental question:

which wires should be connected to mains?
  Reply With Quote
Old 8th March 2012, 08:05 AM   #10
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Is blue isolated from every other wire end?

If so then it could be an electrostatic screen between primary and secondary.

Can you tell if the brown wire is wound closest to the core?
That could be the "end tapping" of the primary winding.
You need to find the other "end tapping".
It may be the blue wire showing 59r
Check the resistance from blue to all the other primary wires. Are any more than 59r?
Check from Yellow to all the other primary wires. Are any more than 59r?
Once you know that you have found the highest resistance winding then it is safe to assume it is the main connection for power in.

With all the wires still safely screwed into their separate terminals, connect the longest winding via the bulb tester to mains power.
Stand back and switch on.
Did the bulb glow, or flash, or nothing at all, or go bright. Stop there and report back.

Be very careful !!!!
The reds wires may be at very high AC voltage.
__________________
regards Andrew T.

Last edited by AndrewT; 8th March 2012 at 08:09 AM.
  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 wiring (Need Help) fingerboy21 Tubes / Valves 6 13th April 2011 03:15 AM
Wiring Buck Transformer with GE transformer Help! HP8903B Tubes / Valves 20 8th January 2011 08:52 PM
How to wiring the transformer olaychang Tubes / Valves 7 2nd February 2009 05:07 AM
transformer wiring homertooties Power Supplies 3 12th June 2007 08:19 AM
Transformer Wiring? Killjoy99 Parts 4 2nd October 2004 11:00 PM


New To Site? Need Help?

All times are GMT. The time now is 01:49 AM.


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