Dual transformer polarity/wiring - Page 2 - diyAudio
Go Back   Home > Forums > General Interest > Everything Else

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

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 2nd March 2007, 12:07 PM   #11
soongsc is offline soongsc  Taiwan
diyAudio Member
 
soongsc's Avatar
 
Join Date: Mar 2005
Location: Taiwan
I think connecting two transformers together is not a good idea since the phase relationship between the primary and secondary might not be exactly the same. I would connect these through two rectifiers first and then pull the DC together.
__________________
Hear the real thing!
  Reply With Quote
Old 2nd March 2007, 12:20 PM   #12
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi Soon,
I suspect even your third alternative will similarly make no difference to the sound output, other than the loss of that extra 1.4volts will have on earlier clipping.
__________________
regards Andrew T.
  Reply With Quote
Old 3rd March 2007, 12:05 AM   #13
soongsc is offline soongsc  Taiwan
diyAudio Member
 
soongsc's Avatar
 
Join Date: Mar 2005
Location: Taiwan
Quote:
Originally posted by AndrewT
Hi Soon,
I suspect even your third alternative will similarly make no difference to the sound output, other than the loss of that extra 1.4volts will have on earlier clipping.
I'm not sure where that 1.4Volts comes from. But I once used a transformer that had two 25V outputs rather than centertapped, connecting two in series created a little 60Hz little signal (little worm between flats that occur at around 60Hz) in the ground loop that could never be removed. Perhaps there is a different explanation?
__________________
Hear the real thing!
  Reply With Quote
Old 3rd March 2007, 07:05 AM   #14
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
two rectifiers loses 2.8v whereas one rectifier loses 1.4v. I think you saw that.

Bad grounding caused the buzz, not the change to/from single rectifier.
__________________
regards Andrew T.
  Reply With Quote
Old 3rd March 2007, 08:09 AM   #15
soongsc is offline soongsc  Taiwan
diyAudio Member
 
soongsc's Avatar
 
Join Date: Mar 2005
Location: Taiwan
Well, looking at the shape of the signal did not convince me it was a grounding problem, and switching from a two secondary to a center-tapped one took care of the problem in my case. So I would not connect two transformers together directly.
__________________
Hear the real thing!
  Reply With Quote
Old 20th March 2007, 03:19 PM   #16
diyAudio Member
 
deduikertjes's Avatar
 
Join Date: Aug 2005
Quote:
I would connect these through two rectifiers first and then pull the DC together.
For me this is definitely the better option. I tried both.

In my system neg. and pos. supply lines are not equally loaded en by this both transformers are not equally loaded, but connected to each other. This resulted in some mechanical hum in the transfromers. Going to two rectifiers cured that. This also cured the difference in output voltage for the pos. and neg. half of my supply. They are now within 0.1 V (was 1.8).

The resulting voltage under load was actually a little higher with the two rectifier option, so it's not sure if you'll lose to extra 1.4 Volts mentioned.

By the way on TNT audio the two rectifier option is preferred for 1 transformer with centretap as well. At least it takes some load of the rectifier.

greetings, MArco
  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 Polarity WRyan Tubes / Valves 5 8th February 2009 12:51 PM
Help with phase/polarity of transformer jakebrown5 Power Supplies 21 27th August 2007 01:38 AM
Does (primary) transformer AC polarity matter...? ptwining Class D 14 28th October 2006 12:19 PM
Question about Dual Polarity Power Supp. (Ashamed to ask) TaaJ Chip Amps 11 28th August 2004 09:27 PM


New To Site? Need Help?

All times are GMT. The time now is 08:02 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