Chipamp.com PSU with CT transformer - 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 31st January 2008, 08:08 AM   #1
diyAudio Member
 
Join Date: Jan 2004
Location: Cape Town
Default Chipamp.com PSU with CT transformer

Loads of people in the past have asked about wiring up the chipamp.com PSU boards for use with a center tap transformer. While these threads have been helpful, I want to check I have the right idea before I mod the boards. Most of the threads I have found keep the dual bridge nature of the supply - something that I don't really want to do.

The original PSU schematic can be found here:
http://www.chipamp.com/images/ps.gif

My proposed modification to the schematic is this attached. It is meant to change the power supply to a single full bridge supply. Can somebody check it and tell me if it's going to work as I expect it to?
Attached Images
File Type: gif ps_modified.gif (9.3 KB, 468 views)
  Reply With Quote
Old 31st January 2008, 08:23 AM   #2
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
the interpretation of the discrete bridge is correct.
Don't use both +pgnd & -pgnd, just use one wire.
__________________
regards Andrew T.
  Reply With Quote
Old 31st January 2008, 08:41 AM   #3
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Howabout a photo?
Attached Images
File Type: jpg chipamp 004.jpg (63.4 KB, 442 views)
  Reply With Quote
Old 31st January 2008, 10:50 AM   #4
diyAudio Member
 
Join Date: Jan 2004
Location: Cape Town
Thanks AndrewT, that's good to know.

Quote:
Originally posted by danielwritesbac
Howabout a photo?
I can't take a photo, because I don't have the boards yet I will take photos when I receive the boards and have made the required mods.
  Reply With Quote
Old 31st January 2008, 01:11 PM   #5
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Default Okay, Howabout a nicer photo?

The photo was for you, not for me. I don't need a photo of this because I already have one.

P.S. With CT transformer, the ground hookup at the amplifier is marked "CG"
The ground lead for chassis is, instead, at the tail end of the power supply (see the bridge between PG in photo below).
The ground lead for signal input goes only to source device(s).
The ground lead for speaker goes only to speaker.

See photo--this photo.
Attached Images
File Type: jpg chipampsupply2.jpg (95.4 KB, 420 views)
  Reply With Quote
Old 31st January 2008, 01:25 PM   #6
diyAudio Member
 
Join Date: Jan 2004
Location: Cape Town
Oh, thanks - sorry I misunderstood.

You seem to be using eight diodes, instead of the four that would be required for a single full bridge. I assume this is because you are using dual bridges. What was your reason for choosing such a configuration? Was it just to minimize changes to the board?
  Reply With Quote
Old 31st January 2008, 02:24 PM   #7
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Quote:
Originally posted by cabbagerat
Oh, thanks - sorry I misunderstood.

You seem to be using eight diodes, instead of the four that would be required for a single full bridge. I assume this is because you are using dual bridges. What was your reason for choosing such a configuration? Was it just to minimize changes to the board?

I'm using 4 diodes. It was helpful for me to download the MUR860 manual and mark the customary stripe on them with the paint marker. I also sat down and sketched the circuit with pencil and paper.

My use of it corresponds somewhat with the directions given on the earlier LM3875 kits. That manual could be at audiosector.com.

If you click on the two photos (above), they will enlarge.

EDIT: Note that the two halves of the ground (+pgnd & -pgnd) are tied together at both ends of the board. That forms the "just one wire" for CG, common ground of the power supply, corresponding to a hookup point by the same name, on the amplifier boards.
  Reply With Quote
Old 31st January 2008, 08:51 PM   #8
diyAudio Member
 
Join Date: Jan 2004
Location: Cape Town
Thanks Andrew and danielwritesbac, you have been most helpful.
  Reply With Quote
Old 1st February 2008, 01:40 PM   #9
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
I described it here as well: http://www.diyaudio.com/forums/showt...83#post1196283
__________________
www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
  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
Heatsinking/transformer for big chipamp? Arx Chip Amps 5 3rd March 2007 08:20 AM
Transformer question for Chipamp... john65b Chip Amps 64 10th October 2006 01:45 PM
UK (?EU) Transformer for Chipamp Group Buy jimbo1968 Group Buys 2 12th June 2005 01:00 PM


New To Site? Need Help?

All times are GMT. The time now is 04:15 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