12v cooling fans

[Doug]

Originally Posted by midgetwaiter

Do you know if that is a regulated power supply Doug?

A regulated power supply will deliver 12v at anything up to it's rated current. An unregulated power supply, which most cheap ones are, will only deliver 12v at exactly it's rated current. If you are drawing a smaller amount of current the voltage goes up.

In your situation I would expect your power supply to deliver something more like 14v at half it's rated current. This is not a big deal from a safety POV but I've noticed that it tends to make the fans noisy if they are driven too hard. You can just add a resistor to the circuit if you need to match the current draw.

Not sure but its a PA cheapie.

So could I just put some form of speed controller on them? Thats resistor based is it not?

I,m thinking I should just by another and have one come on with the halide and the other fan regulated by the RK2 temp controller.

[Skimmerking]

i would just get the multi power one that i have there doug that ones tha go from 3w 5w 7w 9w 10w 12 w

[mseepman]

That's what I did...I run a 1000mA variable power supply and connected them to 3 Princess auto fans...and run them at the voltage that makes the least noise while providing enough air.

Still ended up being too loud for me so I bought some good fans at www.ncix.com and they push 3x the air at half the noise. In my opinion, other than their tiny size, the PA fans are a temporary solution if noise or lack thereof is important to you.

[midgetwaiter]

Originally Posted by Doug

Not sure but its a PA cheapie.

So could I just put some form of speed controller on them? Thats resistor based is it not?

Yep, technical term is potentiometer but it's really a variable resistor.

[KrazyKuch]

Originally Posted by banditpowdercoat

Yup, can run 4 .25mA fans. If you want real power, get a old computer power supply. They can power a ton of fans. Plus, you have 12v and 5v and you can mix it to get 7v So, you can run a fan at 7v no problem, little slower, less flow but alot quieter used to do that in my overclocked computers all the time.

In case anyone cares, to turn on a computer Pwr supply, connect the Green wire to ANY black one.
Yellow to Black 12Vdc
Red to Black 5Vdc
Yellow to red, 7Vdc

Ummmm...I have had a couple power supplies were you have had to take the green to ground to make them turn on!!!!

[Doug]

Now that its been running the duel fans, I notice the power supply is fairly warm to the touch. How much would be normal? Cant say as I ever noticed it before when running a single.
Thanks

[banditpowdercoat]

It should be fine, Doug. Power supply's can get warm, as long as its not HOT. If you can hold it, its ok. They usually are designed to burn out before they cause a fire or anything anyways

[Doug]

Thanks Dan. I put a little cooling fan to cool the power supply for the cooling fans.