Right on duck, but I would use a 10k for the 3.3 and 20-35k for the 5v.
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Right on duck, but I would use a 10k for the 3.3 and 20-35k for the 5v.
Any reason (other than quicker & more responsive adjusting)? I just did my 3.3v and 5v, both with the 68/1K combo. Worked like a charm. The only problem is that it took forever to turn the damn 1K and get ANY sort of noticeable rise (talk about fine tuning :)). It did work just fine, though.
Anything I'm overlooking?
Lower ohm gives more stable rail, as was said earlier... although if 68k works, 68k works.
Yeah, that's why I asked about fluctation. So far, though, it's absolutely rock solid at 3.39v (BIOS reading). :) (and 5v is stable at 5.08v).Quote:
Originally posted by STEvil
Lower ohm gives more stable rail, as was said earlier... although if 68k works, 68k works.
:thumbsup:
hi guys,
i'm just wondering if i can just change the pot on the front panel of a tc550w?
Very nice OC !!! I think this is the best OC I've ever made. Right on the power source!!!! I'm gonna try with 10ohm to 60 ohm plus 5K ohm variable resistor.
Mine is HEC 475 watts true power ( I think the company is marketing this PSU under Enermax brand for US market ).:banana:
hi,
good idea this mod , but i've not understand how you can determinated the value of the resistor and the pot ;
3.3v=1k vr (pot) + 10 ohm (r)
5 v = 20k vr? (pot) + 68 ohm (r) ?
12v = 10k vr (pot ) + 68 ohm (r)
that's for the antec true power 430w , 480w & 550w .
the 5v value seems right ?
somebody could show me these formula with the correct value :
vout = vr/(vr+10)*vin
vout=? 3.3,5,or 12 ???
vr=?
why 10?
vin=?3.3,5 or 12???
wont need a 20vr or 68 ohm for the 5v.
5k and 30ohm would be about perfect probably.
thanks stevil for your reply , may be could you explain how you can find these value ? wath is the formula ?
kind regards ,tomati
well, if 3.3v uses 10 ohm and 1k, and 12v uses 68 ohm and 10k, then somewhere in the center is ~30ohm and 5k...
If you want to get really technical...
3.3v.......12v...........5v
10ohm 68ohm = 22ohms
1Kohm 10Kohm = 2.9K ohms
10ohm/3.3v to 68ohm/12v is a 6.8/3.2 times increase.
1Kohm/3.3v to 10Kohm/12v is a 10/3.2 times increase.
Going to 5v, we would get
approximately 22ohms and 2.9Kohms..
I used a graph to do the more specific measurements, btw. My guess wasn't too far off.. 8-)
To do the graph yourself, grab a chunk of graph paper and label one axis 1-10 and the other axis 1-12 (center point where they touch being 0). 1-12 is your voltage line, 1-10 represents ohms or Kohms.
Ohms: plot at 3.3v/10ohms (1 on 1-10 scale) and 12v/68ohms (6.8 on 1-10 scale), then draw a line and where it crosses 5v should be about 22 ohms (2.2 on 1-10 scale).
KOhms: plot at 3.3v/1Kohms (1 on 1-10 scale) and 12v/10Kohms (10 on 1-10 scale), then draw a line and where it crosses 5v should be about 2.2Kohms (2.2 on 1-10 scale).
I hate math... 8-)
Keep forgetting I cant upload an attachment after i've posted.. oh well.
Heres what I mean, done with psp6 and the grid function 8-)
good explaination stevil , i like understand what i'm doing , no need to like math with your drawn , the best way for learn , thanks man , tomati.
np
I find this japanese website talking about modding 3.3V and 5V for Antec 430 watts:
http://www005.upp.so-net.ne.jp/octo/pc/
http://www005.upp.so-net.ne.jp/octo/...s/image010.jpg
http://www005.upp.so-net.ne.jp/octo/...s/image011.jpg
http://www005.upp.so-net.ne.jp/octo/...s/image012.jpg
keep on moddin!!:banana:
What a horrible place to put your VR's. You won't be able to turn your screwdriver 360 degrees.:confused: :p:Quote:
Originally posted by asw7576
http://www005.upp.so-net.ne.jp/octo/...s/image012.jpg
keep on moddin!!:banana:
i'd stick them on the back like that, but so they point right off the left hand side of the PSU in that pic... then you just gotta pop off the side and turn them, plus less worry about people messing with them since they would have to know they were there.. 8-)
hi,
i've done this with 10ohm + 1k for 3.3v rail
68ohm + 10k for 5v and 12v rails ...and it works nice..but when i push 12v rail up to 12.2v or something (bios reading) my cpu goes unstable...any logical explication for this? :( before the mod it was @ 11.67v...
[]'s
get a reading at the molex.
Your bios may be reading low and your motherboard may not like going too high.
Good and informative tread you have here! I had no fixed resistors at home right now so i couldnt do the mod to my TP550 tonight. But i had some 20 turn VRs, so i tried just soldering a 20k one to an old PSU i was about to get rid of.
http://promodders.dajm.com/anv/uploa...y/Vridpott.JPG
It was no problem adjusting the 3.3V(the only rail with a thin sense line)
But im not willing to do this to my TP550 if i don´t get an ok from you experts:) Would there be any problems when not using any fixed resistors you think? like to much fluctuation or whatever?
It was mentioned as working earlier in the tread, I believe.
I tried that with a shottkey diode, as it was also mentioned as working, but it wouldn't work for either of my PSU's.
Whatever works.. 8-)
I did the mod. There are two TL431 voltage reference IC inside my PSU ( HEC 475 & 525 ). One to control 3.3V, and another one to control 12V & 5V together.
All I need is to add variable resistor to pin 1 & 2 on TL431. a 10K VR for 3.3V, and 100K VR for 12&5 V. They are set to 5K ohm and 60K ohm respectively.
The mod run succesfully, I can go up to 13V, 5.7V, and 3.9V. Of course, I don't recommend these number for use. It's just too much!!! Additional 3% to 5% increase is about right. For examples: 12.36V, 5.15V, 3.40V measure on its connector.
Infact, my system lose stability with very high voltage. So, I use 3% method.
I have another question: My another PSU is going mad. I suspect there is something wrong. The voltage is going up to 14V very fast and it cut off. One thing for sure, If you mod the PSU three times ( solder the VR and replace the VR again and again ) It gonna screw up something, may be the controller IC is screwed up. Do you guys suggest to test it again with mobo connected? I think, It's screw up because there is no load reason.
Anyone ever had this issue?
Anyone have pictures of their mods? I can't seem to visualize this (and if I can't see it, I'm not doin it!) ;D
Quote:
Originally posted by Saffire
Anyone have pictures of their mods? I can't seem to visualize this (and if I can't see it, I'm not doin it!) ;D
OK.... I have some voltmod pics. I need somebody to host the pics. Do you know anybody?
I can host pics, PM me.
I broke the leg off my last 1K VR so I used a resistor instead, 500ohm gave my 3.52V, 1K gave 3.44V. (No load, was at 3.37V before mod)
I didnt use the 60ohm, I just hooked the sense wire to the 500ohm resistor (instead of the 1K VR) then to a ground.
Heres my pics of what I got so far....
Before
http://s88708673.onlinehome.us/pics/...d/IMAG0018.JPG
grounded the resistor to a ground on the 20pin
http://s88708673.onlinehome.us/pics/...d/IMAG0020.JPG
results
http://s88708673.onlinehome.us/pics/...d/IMAG0023.JPG
Did the 5 and 12V, I used 10K's to the same ground wire I used for the 3.3V. I set them both to about 1.4K and the power supply came on the first time when I was doing the 5 and the 12V.