Overclock.net › Forums › Cooling › Cooling Experiments › Fan 24V overvolt!
New Posts  All Forums:Forum Nav:

Fan 24V overvolt! - Page 6

post #51 of 59
Quote:
Originally Posted by TIGR View Post
Really the main reason is for simplicity on the customer's part—so they can just plug in a single power cord and go. Sounds kind of silly.... But, well, I've learned that when it comes to building computers for people, the simpler I make things for them, the less headache medication I have to keep around for myself.


See? That totally makes sense. I knew there had to be some reason.
post #52 of 59
Quote:
Originally Posted by TIGR View Post
Can someone who understands the laws governing electricity better than I do, explain whether or not this can be safely done, why, and from where the 2.4a of the six fans will be drawn if powered between the +12v and -12v rails?
You need to understand that to get 24V from the +12v and -12v you need to wire them in series (one after another).

When in series, the current flowing through the wire loop (psu->fan->psu) is the same at all points. So in your case the 2.4A is required for the fans, so 2.4A is going through the -12V and the +12V.

This excedes the limit for your power supply as you mentioned it was less than 1A. Bet case scenario, you connect it up and the PSU may shut off, or something.. worst case you could damage it.



As for the general topic here on overvolting fans... (and as some people have found). The fans could run faster when overvolted, but you are more likely to melt the windings in the motor, or destory the circuits on the fan (PWM fans for example have control circuits as well). Still fun to try if you don't care about the fan lol.
Desktop
(13 items)
 
  
CPUMotherboardGraphicsRAM
I7 920 D0 Gigabyte X58A-UD5 2 x XFX 5770 xfire 6GB DDR3 OCZ Gold 8-8-8-24 
Hard DriveOptical DriveOSMonitor
1TBx2 Raid 0 Bluray/HDDVD/DVD + DVDRW Windows 7 x64 Dell 27" 2707WF 
PowerCaseMouse
Corsair 750W HAF 932 Razer Death Adder 
  hide details  
Reply
Desktop
(13 items)
 
  
CPUMotherboardGraphicsRAM
I7 920 D0 Gigabyte X58A-UD5 2 x XFX 5770 xfire 6GB DDR3 OCZ Gold 8-8-8-24 
Hard DriveOptical DriveOSMonitor
1TBx2 Raid 0 Bluray/HDDVD/DVD + DVDRW Windows 7 x64 Dell 27" 2707WF 
PowerCaseMouse
Corsair 750W HAF 932 Razer Death Adder 
  hide details  
Reply
post #53 of 59
One of my Sunon's at 24v

film_go.pngYouTube- 120mm fan at 24v
The Fox Box
(16 items)
 
Macbook Pro
(10 items)
 
 
CPUMotherboardGraphicsRAM
Intel 3930K ASUS P9X79 ASUS GTX 570 DCII 4 x 4GB G.Skill Sniper 1600MHz LV 
Hard DriveOptical DriveCoolingOS
Intel 330 - 180GB LG HDDVD & Blu Ray Reader Cooler Master Hyper 612 Windows 7 Ultimate 64bit 
MonitorMonitorKeyboardPower
HP ZR30w Samsung 2243BWX Ducky! PCP&C 750w Silencer (coppa) 
CaseMouseMouse PadAudio
Lian Li PC-E8 G9x S&S Steel Onkyo Receiver/Design Acoustics 2.1 system 
CPUGraphicsRAMHard Drive
Core i5 2410M HD 3000 8GB 120GB SSD 
Optical DriveOSOSOS
Super Drive OSX 10.7.2 Win 7 Enterprise (In VB) Ubuntu 10.04 (In VB) 
MonitorPower
13" 1280x800 65w Magsafe 
CPUMotherboardRAMHard Drive
Q9300 Gigabyte P35 8GB DDR2 2TB WD 
Hard DriveHard DriveHard DriveHard Drive
2TB WD 2TB Seagate 1.5TB Seagate 1.5TB Seagate 
Hard DriveHard DriveHard DriveOptical Drive
1TB Hitachi 1TB Hitachi 500GB WD DVD-RW 
OSMonitorKeyboardPower
Win Server 2012 Headless/15" touchscreen Apple mini USB PC P&C 500W 
  hide details  
Reply
The Fox Box
(16 items)
 
Macbook Pro
(10 items)
 
 
CPUMotherboardGraphicsRAM
Intel 3930K ASUS P9X79 ASUS GTX 570 DCII 4 x 4GB G.Skill Sniper 1600MHz LV 
Hard DriveOptical DriveCoolingOS
Intel 330 - 180GB LG HDDVD & Blu Ray Reader Cooler Master Hyper 612 Windows 7 Ultimate 64bit 
MonitorMonitorKeyboardPower
HP ZR30w Samsung 2243BWX Ducky! PCP&C 750w Silencer (coppa) 
CaseMouseMouse PadAudio
Lian Li PC-E8 G9x S&S Steel Onkyo Receiver/Design Acoustics 2.1 system 
CPUGraphicsRAMHard Drive
Core i5 2410M HD 3000 8GB 120GB SSD 
Optical DriveOSOSOS
Super Drive OSX 10.7.2 Win 7 Enterprise (In VB) Ubuntu 10.04 (In VB) 
MonitorPower
13" 1280x800 65w Magsafe 
CPUMotherboardRAMHard Drive
Q9300 Gigabyte P35 8GB DDR2 2TB WD 
Hard DriveHard DriveHard DriveHard Drive
2TB WD 2TB Seagate 1.5TB Seagate 1.5TB Seagate 
Hard DriveHard DriveHard DriveOptical Drive
1TB Hitachi 1TB Hitachi 500GB WD DVD-RW 
OSMonitorKeyboardPower
Win Server 2012 Headless/15" touchscreen Apple mini USB PC P&C 500W 
  hide details  
Reply
post #54 of 59
I just wanted to add this is a good way to smoke a PSU, as the negative rails are very low current. Really anything that is gonna draw more than 500mA could be enough to smoke a good PSU, not to mention you will likely smoke most fans when overvolting them.

Quote:
You need to understand that to get 24V from the +12v and -12v you need to wire them in series (one after another).

When in series, the current flowing through the wire loop (psu->fan->psu) is the same at all points. So in your case the 2.4A is required for the fans, so 2.4A is going through the -12V and the +12V.

This excedes the limit for your power supply as you mentioned it was less than 1A. Bet case scenario, you connect it up and the PSU may shut off, or something.. worst case you could damage it.



As for the general topic here on overvolting fans... (and as some people have found). The fans could run faster when overvolted, but you are more likely to melt the windings in the motor, or destory the circuits on the fan (PWM fans for example have control circuits as well). Still fun to try if you don't care about the fan lol.
Spot on.. So basically this is not a good idea at all, if you do wanna overvolt fans get some kinda separate adjustable PSU or something.. or better yet get some quality fans to begin with. In the end most fans will probably only reliably run at 14v anyways. last thing I would want is a smoked fan while im away from my computer.. so long story short this is a bad idea imo.
My System
(13 items)
 
  
CPUGraphicsRAMHard Drive
1090T GTX580 16GB PC3-12800 Corsair Force3 120Gb x2 Raid 0 
OSMonitorKeyboardPower
Windows 7 Ultimate 2x HP LP2475W Steelseries 7G Corsair Ax1200 
CaseMouseMouse Pad
TJ-07 Steelseries Sensei Steelseries Qck heavy 
  hide details  
Reply
My System
(13 items)
 
  
CPUGraphicsRAMHard Drive
1090T GTX580 16GB PC3-12800 Corsair Force3 120Gb x2 Raid 0 
OSMonitorKeyboardPower
Windows 7 Ultimate 2x HP LP2475W Steelseries 7G Corsair Ax1200 
CaseMouseMouse Pad
TJ-07 Steelseries Sensei Steelseries Qck heavy 
  hide details  
Reply
post #55 of 59
Quote:
Originally Posted by OBCblackhawk View Post
....get some quality fans to begin with. In the end most fans will probably only reliably run at 14v anyways.
Just a note: this may be true for typical 12v fans, but there are a lot of high-quality 24v and 48v fans out there intended for server usage.
post #56 of 59
There are a couple of different option for powering the 48 volt power supply, you could either open up the regular power supply and run some power wires from the AC side to your 48v then use a relay on your green sense wire to your motherboard. If you don't want to open your 12v power supply, you can use a small power strip mounted either inside the case or on the outside to supply voltage to both, then you would just need to plug in the strip.

If this is a server build, some chassis can accept hot swappable 48v power supplies, you just need to supply power to the chassis itself and it will "distribute" the AC power.
 
VM Server
(15 items)
 
 
CPUMotherboardGraphicsRAM
2600k ASRock Z68 Extreme 4 Sapphire 7970 8GB Vengeance 1600 CL8 
Hard DriveOptical DriveOSMonitor
Crucial M4 256GB HP dvd1160i Windows 7 x64 Ultimate Samsung BX2231  
MonitorMonitorMonitorKeyboard
Samsung BX2231  Samsung BX2231  Panasonic 42" Plasma  Ducky Shine Green LED with Red Switches 
PowerCaseMouse
Corsair 750w Fractal Midi  G500 
CPUMotherboardRAMHard Drive
Intel i7 3770s Asrock Z77 Extreme-m 32GB G.SKILL Ripjaws X Series Samsung F3 1TB 
Hard DriveHard DriveHard DriveHard Drive
Western Digital 2TB Green Seagate Barracuda 1Tb  Western Digital 500GB Western Digital 250GB 
CoolingOSPowerCase
Dark Knight II ESXi 5.1 Antec Earth Watts 380w RAIDMAX Platinum 
OtherOtherOther
iStarUSA Four 3.5in drive in Three 5.25in Hot S... IBM m1015 - IT Flash IBM m1015 - IT Flash 
  hide details  
Reply
 
VM Server
(15 items)
 
 
CPUMotherboardGraphicsRAM
2600k ASRock Z68 Extreme 4 Sapphire 7970 8GB Vengeance 1600 CL8 
Hard DriveOptical DriveOSMonitor
Crucial M4 256GB HP dvd1160i Windows 7 x64 Ultimate Samsung BX2231  
MonitorMonitorMonitorKeyboard
Samsung BX2231  Samsung BX2231  Panasonic 42" Plasma  Ducky Shine Green LED with Red Switches 
PowerCaseMouse
Corsair 750w Fractal Midi  G500 
CPUMotherboardRAMHard Drive
Intel i7 3770s Asrock Z77 Extreme-m 32GB G.SKILL Ripjaws X Series Samsung F3 1TB 
Hard DriveHard DriveHard DriveHard Drive
Western Digital 2TB Green Seagate Barracuda 1Tb  Western Digital 500GB Western Digital 250GB 
CoolingOSPowerCase
Dark Knight II ESXi 5.1 Antec Earth Watts 380w RAIDMAX Platinum 
OtherOtherOther
iStarUSA Four 3.5in drive in Three 5.25in Hot S... IBM m1015 - IT Flash IBM m1015 - IT Flash 
  hide details  
Reply
post #57 of 59
Quote:
Originally Posted by Imrac View Post
There are a couple of different option for powering the 48 volt power supply, you could either open up the regular power supply and run some power wires from the AC side to your 48v then use a relay on your green sense wire to your motherboard. If you don't want to open your 12v power supply, you can use a small power strip mounted either inside the case or on the outside to supply voltage to both, then you would just need to plug in the strip.

If this is a server build, some chassis can accept hot swappable 48v power supplies, you just need to supply power to the chassis itself and it will "distribute" the AC power.
Thank you—exactly the answer I was looking for. Gave you rep.

Most of my 12v PSUs have already been opened up anyway so that's no prob. Actually, connecting the AC sides of both PSUs and adding a relay wire was exactly what I had in mind.
post #58 of 59
i tried this with a couple of fans, worked with 2 of them, but when i try on my new, bigger fans, it doesnt work, just shorts the psu out, ideas?

p.s. im using a old psu to test, lol.
o_0
(13 items)
 
  
CPUMotherboardGraphicsRAM
AMD Athlon ll x4 640 Asus M4A785-M Geforce 8600 GTS Kingston HyperX 2GB 1066 
Hard DriveOptical DriveOSMonitor
1x 1.5tb 7200rpm 2x 2tb 5400rpm Sony dvd/cd burner Windows 7 ultimate 1600x1200 + 1280x1024 (crts) 
KeyboardPowerCaseMouse
logitech "wave" K350 430w pos DYNAPOWER USA Prestige Black / Silver logitech M510 
Mouse Pad
walmart cheap-o 
  hide details  
Reply
o_0
(13 items)
 
  
CPUMotherboardGraphicsRAM
AMD Athlon ll x4 640 Asus M4A785-M Geforce 8600 GTS Kingston HyperX 2GB 1066 
Hard DriveOptical DriveOSMonitor
1x 1.5tb 7200rpm 2x 2tb 5400rpm Sony dvd/cd burner Windows 7 ultimate 1600x1200 + 1280x1024 (crts) 
KeyboardPowerCaseMouse
logitech "wave" K350 430w pos DYNAPOWER USA Prestige Black / Silver logitech M510 
Mouse Pad
walmart cheap-o 
  hide details  
Reply
post #59 of 59
you need a bigger -12v amperage rating on your PSU
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Cooling Experiments
Overclock.net › Forums › Cooling › Cooling Experiments › Fan 24V overvolt!