transformer secondaries question - 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 8th January 2005, 06:20 PM   #1
endia is offline endia  Turkey
diyAudio Member
 
Join Date: Sep 2004
Location: istanbul
Default transformer secondaries question

hello all,
this is my first post on diyaudio

i bought a 225VA 18-0-18 toroidal transformer from a local dealer. actually i asked dual secondaries but they hasn't one and seller pointed out that center wire is actually two wires which are twisted together. he said you can easily seperate them and then you have got dual secondaries. is there any risk if i do this? i'll use it for building a gc.

thanks.
  Reply With Quote
Old 8th January 2005, 07:13 PM   #2
Stocker is offline Stocker  United States
diyAudio Member
 
Join Date: Dec 2003
Location: Austin
6 of one, 1/2dz. of the other. Don't bother separating them unless you just feel like it, if you plan to run a +/- supply to the chip anyhow.
__________________
Jesus loves you.
  Reply With Quote
Old 9th January 2005, 12:42 AM   #3
endia is offline endia  Turkey
diyAudio Member
 
Join Date: Sep 2004
Location: istanbul
Stocker, thanks for the quick replay.
i just want to use one rectifier bridge for each +,- rails instead of one for both rails, doesn't it matter?
  Reply With Quote
Old 9th January 2005, 08:28 AM   #4
wxn is offline wxn  Lithuania
diyAudio Member
 
wxn's Avatar
 
Join Date: Sep 2003
Location: Vilnius
For two rectifiers you must have two separate secondaries, not center-tapped. gl
__________________
Nothing is as simple as it seems
  Reply With Quote
Old 9th January 2005, 12:21 PM   #5
endia is offline endia  Turkey
diyAudio Member
 
Join Date: Sep 2004
Location: istanbul
well, is this the only way for wiring a center-tapped transformer?

Click the image to open in full size.

if so, i'm a bit confused. where to go PG+ and PG- holes on the amplifier board? should i connect both PG+/- holes to the PG? or may i wire them like this? thanks.

Click the image to open in full size.
  Reply With Quote
Old 9th January 2005, 03:32 PM   #6
Sherman is offline Sherman  United States
diyAudio Member
 
Join Date: Feb 2004
Location: Chicago area
Quote:
Originally posted by endia
well, is this the only way for wiring a center-tapped transformer?

Click the image to open in full size.

if so, i'm a bit confused. where to go PG+ and PG- holes on the amplifier board? should i connect both PG+/- holes to the PG? or may i wire them like this? thanks.

Click the image to open in full size.
NO! I have built several GC power supplies using center tapped transformers. Let's call the three secondary leads from the transformer AC1, CT and AC2. Let's call the four connections on the dual bridge power supply AC1H, AC1N, AC2H and AC2N.

I wire AC1 to the AC1H connection in the PS. Then wire the CT to both AC1N and AC2H. Wire the AC2 tap from the transformer to AC2N.

Doing it that way you can use a CT transformer in a dual bridge power supply. The image shows an example with the BrianGT boards.
Attached Images
File Type: jpg ct wiring complete.jpg (29.1 KB, 1555 views)
__________________
--Sherman
  Reply With Quote
Old 9th January 2005, 03:44 PM   #7
Did it Himself
diyAudio Member
 
richie00boy's Avatar
 
Join Date: Nov 2003
Location: Gloucestershire, England, UK
You can wire it like that, but you are wasting half of each bridge and gain none of the advantages of using separate bridges.
  Reply With Quote
Old 9th January 2005, 04:33 PM   #8
SM7UYJ is offline SM7UYJ  Sweden
diyAudio Member
 
SM7UYJ's Avatar
 
Join Date: Dec 2004
Location: Staffanstorp
Hi,
Have not found a clear answer to why two bridges produce a better result. With center tap you still get full wave rectification(sorry for crappy spelling).
Sure half current trough the diodes, but just use bigger ones! What are the advatages of using two bridges? Can some one please explain!
  Reply With Quote
Old 9th January 2005, 05:00 PM   #9
wxn is offline wxn  Lithuania
diyAudio Member
 
wxn's Avatar
 
Join Date: Sep 2003
Location: Vilnius
SM7UYJ:
http://www.tnt-audio.com/clinica/ssps2_e.html
__________________
Nothing is as simple as it seems
  Reply With Quote
Old 9th January 2005, 06:07 PM   #10
SM7UYJ is offline SM7UYJ  Sweden
diyAudio Member
 
SM7UYJ's Avatar
 
Join Date: Dec 2004
Location: Staffanstorp
Hi wxn,
Have actualy read this information before, but I'ts still not clear!
Yes, you get half the current in the diodes but this is only a problem if you have ones not capable of handeling the current = use bigger ones!
Crossover! From what ! Is'nt the circuit made to produce DC for your amp - not the other way arround!? Is'nt this then a 'work arround' for an other problem in the design used?
Larger groundplane! Uhhh...center tap to ground -can it get bigger/shorter/easier!?
I'm a newbee to the audio circuits so excuse my stupidity, but I'm perhaps coloured from building PSUs and amps for hamradio (RF)where demands on DC-ripple and voltage stability under load are much higher and when choosing a trannie - centertapped are prefered by me and many.
Can some one explain ( in simple words ) why use two bridges!?

/RC
  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
One transformer with 4 secondaries or two transformers with dual secondaries Baka Chip Amps 5 28th November 2008 06:39 AM
need help on transformer secondaries connection atenolol50 Tubes / Valves 6 26th September 2008 08:52 AM
how to Using single secondaries transformer for snubber psu triast Chip Amps 18 10th September 2006 10:40 AM
Paralleling transformer secondaries. commstech Parts 4 28th November 2004 06:53 AM
Dangers in connecting transformer secondaries. PetarLD Solid State 8 24th June 2004 02:37 AM


New To Site? Need Help?

All times are GMT. The time now is 02:17 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