Dual polarity power supply with a single secondary transformer? - Page 5 - 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 23rd August 2011, 11:56 AM   #41
Elvee is offline Elvee  Belgium
diyAudio Member
 
Elvee's Avatar
 
Join Date: Sep 2006
Quote:
Originally Posted by godfrey View Post
One thing that might be a problem with that circuit is that with low load current, the output voltages can rise up to double the normal value.
Yes I know.

In fact, this version is not the raw circuit I initially came up with.

After some thinking, clean-up and optimization, I arrived at the conclusion that I could spare two bulky mylar caps by using implicit capacitive dividers, but at the cost of a doubled no-load voltage.

In general, it shouldn't be a problem, but here is the non-abridged version, for cases when the light or no load condition has to be taken into account.
With 4 big caps, it isn't very attractive from a practical point of view.
Attached Images
File Type: gif VirtualCTap3.GIF (57.2 KB, 232 views)
__________________
. .Circlophone your life !!!! . .
♫♪ My little cheap Circlophone© ♫♪

Last edited by Elvee; 23rd August 2011 at 11:58 AM.
  Reply With Quote
Old 28th September 2013, 06:39 PM   #42
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Elvee, is it possible and safe to lower costs and decrease bulk by using series pairs 47uF electrolytic caps (23.5uF bipolar) instead of the 22uF polyester caps??
__________________
Tools, Models & Software for DIYClipNipper boostLM1875 TurboPowerful TDA7293 kitTDA7294 pt2pt ♦ My post has opinion.
  Reply With Quote
Old 28th September 2013, 07:26 PM   #43
Elvee is offline Elvee  Belgium
diyAudio Member
 
Elvee's Avatar
 
Join Date: Sep 2006
Quote:
Originally Posted by danielwritesbac View Post
Elvee, is it possible and safe to lower costs and decrease bulk by using series pairs 47uF electrolytic caps (23.5uF bipolar) instead of the 22uF polyester caps??
I am afraid that is a step too far: a high quality bipolar for crossovers might survive that kind of outrage, but two standards elco's back to back certainly won't....
It will end with a double bang....
__________________
. .Circlophone your life !!!! . .
♫♪ My little cheap Circlophone© ♫♪
  Reply With Quote
Old 29th September 2013, 12:11 AM   #44
AJT is offline AJT  Philippines
diyAudio Moderator
 
AJT's Avatar
 
Join Date: May 2003
Location: Palatiw, Pasig City
Click the image to open in full size.

this is wrong, the safety earth that connects to the chassis metal work has
nothing to do with the psu common or zero reference....

the safety earth is to protect the user from electrocution should
there be massive earth leakage due to component breakdowns...

if you want to get dual polarity supplies out of a single secondary winding then this is what you need...

Click the image to open in full size.

to get dual polarities out of this, make the junction of transformer lead B, C1 and C2
your 0 volt reference and take output voltages at the other ends of C1 an C2......
the circuit shown is a full wave voltage doubler type so transformer utilization will still be quite good...
__________________
the best advertisement for a good audio design is the number of diy'ers wanting to build it after all the years....never the say so of so called gurus....
  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
Single secondary -- dual half wave jmar Chip Amps 2 19th October 2009 01:19 PM
Use a single secondary x-former as dual PSU? pixworld Chip Amps 7 9th March 2009 12:32 PM
DIY balanced power unit with dual 60v secondary transformer? bikehorn Power Supplies 5 8th February 2008 06:59 PM
dual transformer power supply lizgar Power Supplies 6 4th September 2007 08:45 AM


New To Site? Need Help?

All times are GMT. The time now is 03:32 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