Rectifying multiple secondaries.. - 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 10th February 2009, 07:42 AM   #1
diyAudio Member
 
Join Date: Apr 2003
Location: Portland,Oregon
Blog Entries: 4
Send a message via AIM to DigitalJunkie
Default Rectifying multiple secondaries..

So,for a pair of Tube Monoblocks I'm planning,I've got a couple of big Tektronix power transformers with multiple secondaries. I'm wondering if it would be better to series all the secondaries (3x), before the bridge rectifier (basically series them all up,and treat them like one secondary winding) or rectify each one separately,and series them up after the rectifiers.

Connecting them in series post-rectifier,I would incur higher diode losses(3x as much),but I'm wondering if there might be some benefit to doing it that way?
(One I can think of,is the ability to use lower voltage caps.)

Here's a crappy diagram of what I mean;
http://i199.photobucket.com/albums/a...Stuff/PSU2.jpg

And some data on the power trannies in question,from Pete Millet's site (I hope he doesn't mind!):
http://i199.photobucket.com/albums/a...k545A-test.jpg

I am planning on using the 3 windings= 5-10 , 7-14 , 8-15 (Marked in Blue on Pete's graph) as they have lower DCR.


Any thoughts either way?
  Reply With Quote
Old 11th February 2009, 03:52 AM   #2
dtproff is offline dtproff  United States
diyAudio Member
 
Join Date: Oct 2008
Location: Plano, TX, USA
Personally, I don't like stacking caps. For me... One big winding.

For what it's worth.

Tony
  Reply With Quote
Old 11th February 2009, 07:47 AM   #3
diyAudio Member
 
Join Date: Apr 2003
Location: Portland,Oregon
Blog Entries: 4
Send a message via AIM to DigitalJunkie
I see what you're saying. But considering that the B+ is going to be in the 450V neighborhood,I will most likely have to stack some caps to get to (above) that voltage rating anyways. :-/
Although,I suppose I could get some oil motor run caps.I might also be able to use the JJ multisection caps,since they're rated to 500V-That might be a bit close though.
Hummm.. decisions,decisions!
  Reply With Quote
Old 11th February 2009, 03:15 PM   #4
dtproff is offline dtproff  United States
diyAudio Member
 
Join Date: Oct 2008
Location: Plano, TX, USA
FYI...

Digikey has 630V caps but anyway... There really isn't much difference between the two other than possibley a lower ESR for the single HV cap.

Good luck.
  Reply With Quote
Old 11th February 2009, 03:47 PM   #5
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
440Vac motor run caps should have a DC rating ~ 600Vdc.
I wonder if that's where the 630Vdc rating comes from?
__________________
regards Andrew T.
  Reply With Quote
Old 14th February 2009, 09:26 PM   #6
Tweeker is offline Tweeker  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Cincinnati, Ohio
As you get to higher voltage AC rated caps the DC voltage rating is often much higher than 1.4 * RMS. AC duty is typically much more strenuous.

The AC rating is often limited by dissipation etc.

An extreme example, pdf.
__________________
Be sure your foil hat has a good low impedance ground.
  Reply With Quote
Old 15th February 2009, 03:26 AM   #7
diyAudio Member
 
Join Date: Apr 2003
Location: Portland,Oregon
Blog Entries: 4
Send a message via AIM to DigitalJunkie
Wow,2 to 4 times the AC voltage!

Quote:
440Vac motor run caps should have a DC rating ~ 600Vdc. I wonder if that's where the 630Vdc rating comes from?
I have wondered that too,and sort of 'assumed' that was the case.

I'm still pretty undecided,but I'm thinking I'll just rectify each winding,and series up the resulting DC.
  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
Multiple secondaries toroid steveline Chip Amps 29 30th August 2007 06:20 PM
winding multiple secondaries on a toroid??? Puggie Power Supplies 3 9th August 2006 05:58 PM
Multiple secondaries hook-up!!! Klimon Tubes / Valves 4 10th July 2006 02:32 PM
multiple secondaries on a toroid awashi Power Supplies 12 10th July 2005 06:26 AM


New To Site? Need Help?

All times are GMT. The time now is 09:58 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