24v fan on an 12v psu

nikchris · 07-15-2008, 10:17 AM

I recently purchased a fan from ebay that works at 12-24v. I would very much like to try him out at 24v but i was said that my psu is 12v and anything i would do would burn my psu.

Is there any chance to work my fan at 24v? How should i make it safe?

magnethead · 07-15-2008, 10:46 AM

If you run it at 12 volts it will pull double amps. ie rated .5 amp @ 24VDC, it'll pull a full amp at 12VDC.

HOWEVER, please list your PSU model. becuase the PSU does actually put out 24 volts, but not on a high amperage, as it's for the mobo. It's +12 on the positive connector and -12 on the negative connector. But again, it usually only supports up to about 1 amp. my toughpower 650 says .8A.

nikchris · 07-15-2008, 10:59 AM

We have the exact same psu..... :)

magnethead · 07-15-2008, 07:37 PM

While I will already say this is unadvised (otherwise Dai will chew me a new one), you could splice the -12 VDC line and hope there's enough amperage for both the fan and mobo to run.

Your other choice would be to hit up radioshack or walmart for a 24 VDC wall adapter, molex to bare wire power adapter, and a simple single pole relay.

You'd leave the transformer plugged in full time, and use the relay to power up the fan when it senses a molex power feed (the computer being on)

07-15-2008, 10:17 AM	#1 (permalink)
nikchris Registered User Join Date: Dec 2004 Posts: 35 OS: xp pro	24v fan on an 12v psu I recently purchased a fan from ebay that works at 12-24v. I would very much like to try him out at 24v but i was said that my psu is 12v and anything i would do would burn my psu. Is there any chance to work my fan at 24v? How should i make it safe?

07-15-2008, 10:46 AM	#2 (permalink)
magnethead Tech Hardware Team Join Date: Mar 2006 Location: TX Posts: 1,786 OS: XPH, 2K My System Blog Entries: 2	Re: 24v fan on an 12v psu If you run it at 12 volts it will pull double amps. ie rated .5 amp @ 24VDC, it'll pull a full amp at 12VDC. HOWEVER, please list your PSU model. becuase the PSU does actually put out 24 volts, but not on a high amperage, as it's for the mobo. It's +12 on the positive connector and -12 on the negative connector. But again, it usually only supports up to about 1 amp. my toughpower 650 says .8A. __________________ AIM me: MAGNET794 For proper support: what are you running? video card, cpu, m/board, ram, power supply, brand, wattage, any error message? PCI-E requires 26 amps at 12 volts. That's a 650W PSU. Power Supply Info and Selection . Info on thermal compounds & application . TEST PSU USING MULTI-METER

07-15-2008, 10:59 AM	#3 (permalink)
nikchris Registered User Join Date: Dec 2004 Posts: 35 OS: xp pro	Re: 24v fan on an 12v psu We have the exact same psu..... :)

07-15-2008, 07:37 PM	#4 (permalink)
magnethead Tech Hardware Team Join Date: Mar 2006 Location: TX Posts: 1,786 OS: XPH, 2K My System Blog Entries: 2	Re: 24v fan on an 12v psu While I will already say this is unadvised (otherwise Dai will chew me a new one), you could splice the -12 VDC line and hope there's enough amperage for both the fan and mobo to run. Your other choice would be to hit up radioshack or walmart for a 24 VDC wall adapter, molex to bare wire power adapter, and a simple single pole relay. You'd leave the transformer plugged in full time, and use the relay to power up the fan when it senses a molex power feed (the computer being on) __________________ AIM me: MAGNET794 For proper support: what are you running? video card, cpu, m/board, ram, power supply, brand, wattage, any error message? PCI-E requires 26 amps at 12 volts. That's a 650W PSU. Power Supply Info and Selection . Info on thermal compounds & application . TEST PSU USING MULTI-METER