Joining 12v + 5v = 17v?

Redken · 03-10-2005, 08:44 AM

....or pufff!! there goes the psu.

Hi guys!

I have two PSU on my case right now. One powers only my MOBO and video card. The other one the rest of my system.
If I get a 12v line from one and a 5v line from the other one, and combine them to power a TEC. What would happen? A) I blow up both PS. B)Nothing happens C) TEC is powered up to 17v.
I thought about using the two PS because I didn't think it would work using just one (12v + 5v from the same PS). Or will it?

If the above is a horrible mistake. How would I go about powering a 172w 24v TEC between 15v-18v max (which is what I have read to be the best compromise) using my two current PS's?

I'm planning to buy an X800XT PE and modding/Overclocking the living crap out of it

. For this I have decided to go to TEC for the first time.
I think I'll do "OK" with a MCW50-T modded to 172w pelt using this guide

This is the water setup I'm using right now:
- White Water
- MCW20
- MCW50
- 1/2 Clearflex
- 2-342 heater core (2" shroud on both sides)
- 4 Panaflos 120mm L1A push/pull (1 extra for burners)
- Iwaki MD-15RLT (shrouded)
- Lian-Li Pc 70 case (very moded)

Thanks in advance for any help that you can give me.

Long Haired Git · 03-10-2005, 10:11 AM

Check out the watts the -5v line can supply.
Hmmmm, not really up to a TEC now is it?

Redken · 03-10-2005, 11:39 AM

You are right. I'm just not very experienced at this.

Is there a way I could do this?

Redken · 03-10-2005, 12:01 PM

I found this very good article here. Maybe it will help somebody else too.

But I still have a doubt after reading the article.
According to the article I should rig my PS's in series to get 18v. But I would have to disconnect the ground of one of the PS in order to get it to work. Would that affect the rest of the devices connected to that particular PS?

For example, I have one of the PS hooked up to the MOBO and VID card. If I disconnect the ground on that one, will it affect the MOBO and VID?

The author of the article doesn't specify if he used his modded PS's as stand alone units for TEC use only or if he used it for the rest of his system also.

Butcher · 03-11-2005, 03:14 AM

If you're planning to use them in series you should use them as stand alone units - using them with a mobo etc. will likely cause them to be grounded with respect to each other via the mobo and defeat any series linkage you're trying to do.

Redken · 03-11-2005, 07:23 AM

So, do you guys think this would be the most reasonable thing to do?

Quote:

Use the larger of the two PSUs to power EVERYTHING in the system except for the tec. Make sure that the second PSU is ground isolated and hook it in series for your 17v. Power your TEC from that.

Redken · 03-11-2005, 07:48 AM

I also found this info now:

Quote:

Output
DC Voltage Ripple & Noise Total Reg. Output current rating Min / Max
+3.3V 50mV +5%, -4% 0.5A/20A
+5V 50mV +5%, -4% 0.3A/22A
+12V 1 120mV +5%, -4% 1.0A/20A
-12V 120mV ¡Ó10% 0A/0.5A
+5Vsb 120mV +5%, -4% 0.1A/2.2A
+12Vsb 50mV +5% N/A
+3.3V & +5V 145W
Total Power 270W

Over Voltage Protection
+5V: 5.5V~7.0V
+3.3V: 3.7V~4.3V
+12V:13.4~15.6V

Does this mean that if I mod this PSU I can get the 12v line up to 15.6v without a problem? Could I power the TEC @ 15.6v with this single PSU?

cotdt · 08-28-2005, 04:13 PM

there is no improvement in temps by going over 12V in my experience. 12V seems the optimal for those "max 15V" peltiers.

redleader · 08-28-2005, 05:14 PM

I wouldn't go over 12v anyway.

03-10-2005, 08:44 AM	#1
Redken Cooling Neophyte Join Date: Feb 2004 Location: Puerto Rico Posts: 15	Joining 12v + 5v = 17v? ....or pufff!! there goes the psu. Hi guys! I have two PSU on my case right now. One powers only my MOBO and video card. The other one the rest of my system. If I get a 12v line from one and a 5v line from the other one, and combine them to power a TEC. What would happen? A) I blow up both PS. B)Nothing happens C) TEC is powered up to 17v. I thought about using the two PS because I didn't think it would work using just one (12v + 5v from the same PS). Or will it? If the above is a horrible mistake. How would I go about powering a 172w 24v TEC between 15v-18v max (which is what I have read to be the best compromise) using my two current PS's? I'm planning to buy an X800XT PE and modding/Overclocking the living crap out of it . For this I have decided to go to TEC for the first time. I think I'll do "OK" with a MCW50-T modded to 172w pelt using this guide This is the water setup I'm using right now: - White Water - MCW20 - MCW50 - 1/2 Clearflex - 2-342 heater core (2" shroud on both sides) - 4 Panaflos 120mm L1A push/pull (1 extra for burners) - Iwaki MD-15RLT (shrouded) - Lian-Li Pc 70 case (very moded) Thanks in advance for any help that you can give me. __________________ P4C800E DL,P4 2.4c @ 3.4(droop mod),1G Mushkin 3500 II 2,2,2,8 @ 3.1v,AIW 9800 Pro (450/370 @ 1.9v core),Audiology Platinum,2xDiamonds 8mb Raid0,Lian-Li Pc70,PC P & Cooling 510D,Plextor 708A,Plextor 52x32x52...water cooled...

03-10-2005, 10:11 AM	#2
Long Haired Git Cooling Savant Join Date: Jan 2003 Location: Sydney, Oz Posts: 336	Check out the watts the -5v line can supply. Hmmmm, not really up to a TEC now is it? __________________ Long Haired Git "Securing an environment of Windows platforms from abuse - external or internal - is akin to trying to install sprinklers in a fireworks factory where smoking on the job is permitted." (Prof. Gene Spafford) My Rig, in all its glory, can be seen best here AMD XP1600 @ 1530 Mhz \| Soyo Dragon + \| 256 Mb PC2700 DDRAM \| 2 x 40 Gb 7200rpm in Raid-0 \| Maze 2, eheim 1250, dual heater cores! \| Full specifications (PCDB)

03-10-2005, 11:39 AM	#3
Redken Cooling Neophyte Join Date: Feb 2004 Location: Puerto Rico Posts: 15	You are right. I'm just not very experienced at this. Is there a way I could do this? __________________ P4C800E DL,P4 2.4c @ 3.4(droop mod),1G Mushkin 3500 II 2,2,2,8 @ 3.1v,AIW 9800 Pro (450/370 @ 1.9v core),Audiology Platinum,2xDiamonds 8mb Raid0,Lian-Li Pc70,PC P & Cooling 510D,Plextor 708A,Plextor 52x32x52...water cooled...

03-10-2005, 12:01 PM	#4
Redken Cooling Neophyte Join Date: Feb 2004 Location: Puerto Rico Posts: 15	I found this very good article here. Maybe it will help somebody else too. But I still have a doubt after reading the article. According to the article I should rig my PS's in series to get 18v. But I would have to disconnect the ground of one of the PS in order to get it to work. Would that affect the rest of the devices connected to that particular PS? For example, I have one of the PS hooked up to the MOBO and VID card. If I disconnect the ground on that one, will it affect the MOBO and VID? The author of the article doesn't specify if he used his modded PS's as stand alone units for TEC use only or if he used it for the rest of his system also. __________________ P4C800E DL,P4 2.4c @ 3.4(droop mod),1G Mushkin 3500 II 2,2,2,8 @ 3.1v,AIW 9800 Pro (450/370 @ 1.9v core),Audiology Platinum,2xDiamonds 8mb Raid0,Lian-Li Pc70,PC P & Cooling 510D,Plextor 708A,Plextor 52x32x52...water cooled...

03-11-2005, 03:14 AM	#5
Butcher Thermophile Join Date: May 2001 Location: UK Posts: 1,064	If you're planning to use them in series you should use them as stand alone units - using them with a mobo etc. will likely cause them to be grounded with respect to each other via the mobo and defeat any series linkage you're trying to do. __________________ Once upon a time, in a land far far away...

08-28-2005, 04:13 PM	#8
cotdt Cooling Neophyte Join Date: Jul 2005 Location: CALIFORNIA Posts: 50	there is no improvement in temps by going over 12V in my experience. 12V seems the optimal for those "max 15V" peltiers. __________________ SilentPCReview.com Silence = no fans, no harddrive

08-28-2005, 05:14 PM	#9
redleader Thermophile Join Date: Jun 2001 Location: The deserts of Tucson, Az Posts: 1,264	I wouldn't go over 12v anyway.

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