It appears you have not yet registered with our community. To register please click here...

 
Go Back [M] > Hardware Madness > Hardware Overclocking and Case Modding
200W regulable 3,3V PSU 200W regulable 3,3V PSU
FAQ Members List Calendar Search Today's Posts Mark Forums Read


200W regulable 3,3V PSU
Closed Thread
 
Thread Tools
Old 21st September 2008, 19:38   #1
[M] Reviewer
 
geoffrey's Avatar
 
Join Date: Nov 2004
Posts: 4,127
geoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registered
Default 200W regulable 3,3V PSU

Since my OCZ powerstream 600 left the realm of earth I'm without any PSU which features a tweakable 3,3V line. No problem, I've had experience with modding ATX PSU's (Building a 300W Fan Controller from an ATX PSU: http://www.madshrimps.be/?action=gethowto&howtoID=77). I took one of the many elder PSU's I have around and began modifying its output voltage.
Good thing it had a on board trimmer so there was little searching involved, but I discovered that even though the 12V would rise as high as 13.5V, the 3.3V line never went higher then 3.35V. Even higher brought the PSU in lockdown mode. Hmm, but on the other hand I could easily bring down the 5V line as low as 3V, maybe that could be of use?

Well, so I came to the idea to have one PSU feeding all necessary power levels (+12V, +5V, +5V standby,...) except for the 3.3V line, therefore I would use the other ATX PSU which I just modified.

What I had to do is giving both PSU's the same reference 0V. I cut off the ATX connector from the tweakable PSU (slave PSU) and soldered the black wires to the same spot as the black wires inside the main PSU (master PSU). This way 0V is 0V in both PSU's, no floating volt lines here. I also desolderd all ~220V net line cables inside the slave PSU and made a pass-through from the master to the slave PSU so that I would need only one power cord for both PSU's. Next I cut of the green cable from the slave PSU and connected it to the green cable inside the master PSU's, this way both PSU's will power on at the same time. For easier testing purposes I've put an on/off switch in parrallel, its much alike the green wire PSU-on trick.

I also got rid of all the cables I wont ever use with the slave PSU, I will only be using the tweakable 5V line. To keep the colors matching I desoldered the orange 3.3V line cables and put them in place of the red 5V line cables, that's why you see orange cables leaving the PSU. These cables are routed inside the main PSU were I disconnected the original orange cables from the PCB, the original 3.3V line will then be unused. In order to have my 3.3V back at the 20-pins ATX plug I made a connection between the cables from the ATX connector from the master PSU and the orange cables coming from the slave PSU. End result: I have one PSU feeding normal voltages while the second PSU handles the 3.3V line voltage on its own. Via a potentiometer I can easily adjust output voltage of the 3.3V line up to nearly 5V!

A schematic:


Some pictures I took during testing;









Assembled, back side picture:



Assembled front side picture:



And off course a video where I regulate the 3.3V line voltage all the way up to its maximum. Well, I hardmodded the maximum, sure you can get more but what's the point?



Bad video quality due to compression
Left 12,4V
Right 3,2~4,8V
Attached Thumbnails
200w-regulable-3-3v-psu-01.jpg 200w-regulable-3-3v-psu-02.jpg 200w-regulable-3-3v-psu-03.jpg 200w-regulable-3-3v-psu-04.jpg 200w-regulable-3-3v-psu-05.jpg 200w-regulable-3-3v-psu-06.jpg 200w-regulable-3-3v-psu-schematic.png
__________________


Last edited by geoffrey : 26th September 2008 at 21:02.
geoffrey is offline  
Old 22nd September 2008, 10:17   #2
[M] Reviewer
 
Join Date: Jun 2002
Posts: 5,003
piotke Freshly Registered
Default

Geoff, pictures aren 't working ?
__________________
.
piotke is offline  
Old 22nd September 2008, 17:12   #3
[M] Reviewer
 
geoffrey's Avatar
 
Join Date: Nov 2004
Posts: 4,127
geoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registered
Default

Hmm weird, somehow the attachments have been deleted. I'll try to fix them next week
__________________

geoffrey is offline  
Old 26th September 2008, 21:03   #4
[M] Reviewer
 
geoffrey's Avatar
 
Join Date: Nov 2004
Posts: 4,127
geoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registered
Default

All good now
__________________

geoffrey is offline  
Old 26th September 2008, 21:16   #5
Member
 
blind_ripper's Avatar
 
Join Date: Apr 2005
Posts: 1,338
blind_ripper Freshly Registered
Default

nice G , i heard nehalem wil need external voltage's on mem and so . can this be done ?
blind_ripper is offline  
Old 26th September 2008, 22:02   #6
[M] Reviewer
 
geoffrey's Avatar
 
Join Date: Nov 2004
Posts: 4,127
geoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registered
Default

Not really following the Nehalem news, will have a look once they go retail
__________________

geoffrey is offline  
Old 26th September 2008, 22:35   #7
Member
 
blind_ripper's Avatar
 
Join Date: Apr 2005
Posts: 1,338
blind_ripper Freshly Registered
Default

Quote:
Originally Posted by geoffrey View Post
Not really following the Nehalem news, will have a look once they go retail
to bad i faild for the second time on my drivers licens , i would have dropped by to let u look at the 4870 pcb if there is any thing to be modded .

if u have time next weeks theursday or friday let me know .
blind_ripper is offline  
Old 27th September 2008, 10:58   #8
[M] Reviewer
 
geoffrey's Avatar
 
Join Date: Nov 2004
Posts: 4,127
geoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registered
Default

thursday/friday are no go's, weekdays are always bussy
__________________

geoffrey is offline  
Old 13th October 2008, 20:44   #9
[M] Reviewer
 
geoffrey's Avatar
 
Join Date: Nov 2004
Posts: 4,127
geoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registeredgeoffrey Fully Registered
Default

The total unit is working very well on my Gigabyte GA-5SMM socket 7 board, though when using the ASUS P5A board the system does not boot. No idea why, the board only boots with one of the three units I have around here.

Got them PSU's back open, 5V=5V under load but 12V=11,5V under load, I'm going to add regulation so to have higher volts when the system is under heavy stress. Might maybe help getting the SIS530 based motherboard stable at 133MHz strap.
__________________

geoffrey is offline  
Closed Thread


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cooler Master 750 Watt GX PSU jmke WebNews 0 4th March 2010 14:47
Kingwin Lazer 850w PSU jmke WebNews 0 24th February 2010 16:09
Enermax revises Modu82+, Pro82+ and LibertyECO PSU series jmke WebNews 0 2nd February 2010 10:40
Enermax launches 80PLUS® Gold certified PSU series Pro87+ and Modu87+ jmke WebNews 0 14th January 2010 11:41
Luxa2 LM100-Mini Home Theater PC Chassis with 200W PSU jmke WebNews 0 20th September 2009 15:17
Thermaltake Toughpower XT 850W PSU jmke WebNews 0 11th September 2009 14:30
Enermax ECO80+ - Most Silent PSU Series jmke WebNews 0 6th August 2009 14:28
Seasonic M12D 850 Watt PSU jmke WebNews 0 23rd December 2008 09:44
XG Magnum 500W Modular PSU Sidney WebNews 0 14th November 2005 17:47
Very odd psu prpblem. piotke Hardware/Software Problems, Bugs 6 28th October 2004 12:25

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


All times are GMT +1. The time now is 10:11.


Powered by vBulletin® - Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO