24 volt fans?

[gradivus]

Any suggestions for running 24 volt fans in my case? I happen to have a cheap source(free) of NMB 4715ML from HP laser printers and I'm thinking one of these would look great blowing air over my motherboard. I'm thinking I can make a fanbus with a 24V AC adapter, is this a stab in the right direction?

 

[sitka]

24 volts for peltier also. How

 

[evergreen96]

i like to know if this is possible too?

 

[Shelgeyr]

Don't know if this would work, but if you can get access to the +12 and the -12 volts from your power supply that would be 24v... example foloowing...

connect the +12v lead to the positive of you fan, connect the -12 lead to the ground or neg lead of your fan.

any one think this would work?

 

[lenjack]

Yes...It will work.

 

[Moohooya]

Before you go too far with that idea, I believe the -12v rail is fairly obsolete these days, and now only supplies minimal current for the few devices that requires it. Check your PS and see what the maximum current you can draw on the -12v rail is. A fan or two should be OK, a peltier I would doubt. Some of the more expensive PS might have a higher current. My ps is an OK one, and kind of old, so its 0.5 amp rating I'd guess would be on the upper end of what people will have. This gives a total of 12 watts @ 24 volts. Remeber that fans draw more current at start up time, so if you fan only draws 3 watts while running, it could easily be double that when it starts us.

If you are serious about wanting 24 volts, look for a small PS at radio shack and use that.

Moohoo

 

[Jalapeno]

Buy two car batteries, connect them in series, and - voila!

Seriously, a separate PS is probably your best option, although it might cost you a pretty penny as well. Is it worth it?

 

[gradivus]

-12V rail? Huh? How would I go about finding that with a multimeter? Anyway, the separate PSU is an easy possibility, I have a small 90 watt AT I can use.

 

[Jalapeno]

It depends on the kind of meter you are using. If you have a digital one you just measure the voltages and it will display -12V. With an analog one you would have to reverse the leads.