Paralleling transformers??? - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 20th January 2006, 02:29 AM   #1
dfdye is offline dfdye  United States
diyAudio Member
 
dfdye's Avatar
 
Join Date: Dec 2005
Location: USA
Default Paralleling transformers???

I found a few "recycled" transformers locally that are dirt cheap, but won't handle the power I want to put through them. Has anyone used transformers in parallel to get enough juice for an application? I know you can wire transformers in series to double voltages, but I have never seen people use parallel transformers. Thoughts, comments?

I can't think of a good reason this won't work, but I am not an EE, so I figured I would toss out the idea in case others had some insights.
  Reply With Quote
Old 20th January 2006, 02:33 AM   #2
dfdye is offline dfdye  United States
diyAudio Member
 
dfdye's Avatar
 
Join Date: Dec 2005
Location: USA
Well, I think I found the answer (just after I geve up on the search. . . ). I think it will be OK, but of course I didn't find that until just after I posted. Don't you love it when that happens!

Sorry for the wasted post.
  Reply With Quote
Old 20th January 2006, 06:26 AM   #3
lgreen is offline lgreen  United States
diyAudio Member
 
lgreen's Avatar
 
Join Date: May 2003
Location: San Diego, USA
Default how?

what did you find?

If the transformers don't exactly match up you may have currents flowing in them and extra heat generated.
  Reply With Quote
Old 20th January 2006, 12:59 PM   #4
dfdye is offline dfdye  United States
diyAudio Member
 
dfdye's Avatar
 
Join Date: Dec 2005
Location: USA
Default Re: how?

Quote:
Originally posted by lgreen
what did you find?

If the transformers don't exactly match up you may have currents flowing in them and extra heat generated.
Yea, essentially that is what I found. As long as you accept that there will be losses and that it is not as desirable as a single transformer, and that you need to make sure that the outputs are matched pretty well, then you should be OK. That being said, I have not tried it yet, so we will see.

I think I am to the point of dropping a few bucks and trying it out. If it sucks, c'est la vie!
  Reply With Quote
Old 20th January 2006, 01:09 PM   #5
paulb is offline paulb  Canada
diyAudio Member
 
Join Date: Jun 2001
Location: Calgary
I am using parallelled transformers for a Class-A amp I'm building. I used four 0.5 ohm 10W resistors, one between each secondary winding and its associated bridge rectifier input so they share the current properly. It works fine, although they are identical transformers they weren't sharing nicely until I added the resistors.
  Reply With Quote
Old 20th January 2006, 01:13 PM   #6
dfdye is offline dfdye  United States
diyAudio Member
 
dfdye's Avatar
 
Join Date: Dec 2005
Location: USA
Hey Paul,

Thanks for the tip about using resistors! I never would have thought of that.

I was actually planning to use one bridge rectifier for the transformers, but from what it sounds like, you are using a different bridge for each of your yours. Is there a reason for this?

Thanks again!
  Reply With Quote
Old 20th January 2006, 07:33 PM   #7
diyAudio Member
 
Join Date: Jul 2004
Location: .
I have done this before but what I found to work the best is to put a bridge rectifier on each transformer and then you parallel the bridge rectifiers. This way you have nothing fighting with each other. I build a 1000Va using two 500VA secondaries with a bridge rectifier on each secondary

have a look at my mosfet amp. here you can see how i did it.
Attached Images
File Type: jpg mosfet.jpg (69.5 KB, 377 views)
  Reply With Quote
Old 20th January 2006, 08:47 PM   #8
dfdye is offline dfdye  United States
diyAudio Member
 
dfdye's Avatar
 
Join Date: Dec 2005
Location: USA
Quote:
Originally posted by rudi
I have done this before but what I found to work the best is to put a bridge rectifier on each transformer and then you parallel the bridge rectifiers. This way you have nothing fighting with each other.
Absolutely! The diodes would prevent slightly mis-matched transformers from feeding into each other!

That makes 100% sense, but I must admit that rationally didn't even cross my mind until you mentioned it. Thanks!

Oh, and that amp looks great! Extremely clean wiring. I am impressed! My stuff looks like spaghetti most of the time!
  Reply With Quote
Old 28th January 2006, 06:34 PM   #9
diyAudio Member
 
Join Date: Mar 2005
Location: Turku
Quote:
Originally posted by rudi
I have done this before but what I found to work the best is to put a bridge rectifier on each transformer and then you parallel the bridge rectifiers. This way you have nothing fighting with each other. I build a 1000Va using two 500VA secondaries with a bridge rectifier on each secondary
I made 600VA power supply using 3 different transfomers. Voltages was between 33-37V. I put bridge rectifier on each transformer and regulators. Finally I have 3 wires with 29V. Then I parallel them through low resistance power resistors. Same I did on negative side. So total six bridge rectifier and regulators on my GC power supply.
  Reply With Quote
Old 29th January 2006, 02:10 PM   #10
diyAudio Member
 
sagarverma's Avatar
 
Join Date: Feb 2005
Location: NEW DELHI
Quote:
Originally posted by isopannu


I made 600VA power supply using 3 different transfomers. Voltages was between 33-37V. I put bridge rectifier on each transformer and regulators. Finally I have 3 wires with 29V. Then I parallel them through low resistance power resistors. Same I did on negative side. So total six bridge rectifier and regulators on my GC power supply.
nice idea.
__________________
Never Underestimate The Bandwidth of A Station Wagon Full Of Magnetic Tapes Hurtling Down The Highway...................Andrew S Tanenbaum
  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
Paralleling Outputs or Bi-amp Merlot Tubes / Valves 8 14th September 2008 06:00 AM
Paralleling AMP9 jringels Class D 0 12th February 2007 12:32 PM
resistors for paralleling ejn327 Chip Amps 8 7th February 2005 08:10 PM
Paralleling Transformers metal Chip Amps 9 9th July 2004 09:02 PM
Paralleling Transformers metal Chip Amps 8 7th March 2004 09:48 AM


New To Site? Need Help?

All times are GMT. The time now is 06:43 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