12 volt DC output from desktop PSU

[elduece]

I thought it would be a cool idea to use my faulty Enermax EG465P-VE to independently power on 12v cooling fans for intervals of half hour or maybe less. I know for a fact the 12v rail output still works on this unit. Would it be safe to do this with the PS_ON hardwired to common ground for continuous operation? This method is commonly used for PSU troubleshooting. Or should I plugged in an old motherboard with the BIOS enabled "AC power loss recovery" if I want its' output? And having the PSU/or assembly triggered by on/off timer? I'm not really having doubts this could work safely, I just want some opinions or any other safety considerations I might be lacking. I'm in the planning stage for my first low budget enclosed closet contraption. Thank you!

elduece Reviewed by elduece on 04-24-2009. 12 volt DC output from desktop PSU I thought it would be a cool idea to use my faulty Enermax EG465P-VE to independently power on 12v cooling fans for intervals of half hour or maybe less. I know for a fact the 12v rail output still works on this unit. Would it be safe to do this with the PS_ON hardwired to common ground for continuous operation? This method is commonly used for PSU troubleshooting. Or should I plugged in an old motherboard with the BIOS enabled "AC power loss recovery" if I want its' output? And having the Rating: 5

[killerweed420]

Computer power units work great for powering 12v accesories. Plenty of watts to drive just about anything. I use one to power a small carbon scrubber.

[elduece]

Did you do yours the long way(with the motherboard plugged in) or the simpler way with just the PS_ON# switch lead shorted to ground?

[killerweed420]

Nope. Mine is just wired directly to the fan. No switch. I just unplug when not needed.

[syde00]

if you have an old AC adapter that outputs somewhere in the 9-12 VDC range, it would be smarter to cut the tip off that and use it instead.

mainly for efficiency reasons... computer PSUs are actually pretty efficient, but not when they are used for such tiny loads like a single small fan.

that being said, there is nothing unsafe about hardwiring the PSU into a constant-on position... there is actually a company that makes a small devices you plug into the cable that would attach to the main motherboard header that shorts the correct pins for you... i can;t recall who makes it though.

[elduece]

My situation was that I didn't have any spare AC adapters on hand with that type of output except for the old psu just lying around. Believe me, I've already looked around. AFAIK for efficiency concerns, just because its a 450 watt psu doesn't mean that it has to put out 450 watts constant drawing maximum 7-10 amps! -right? I hope not and it doesn't make sense too. This psu will only be powering an old 8cm Vantec Tornado, an 90 mm Sunai and a Taifal 60 mm fan -maybe totaling 7 watts judging by the I ratings detailed on these fans. I've already invested enough monies for this corner of this room, I just really don't want stretch it any further just to power up 12v fans. Thank you!

[scrumby]

Alot of the power is scrubbed off in the form of heat though, thats what those big heat sinks are for. You would be better off with an old laptop charger or something.