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sl4ck
12-20-2005, 12:43 PM
Can someone tell me what 12v Power Supply(AMP) should i use to power 2 x 5W Vapochill Heat Resistor + 2 x 0.50AMP 120mm Fan 24/7 ??

I whant to put a dedicated 12v power suply, or reuse one old pc power supply only for those 4 elements.

http://www.teccentral.de/reviews/cooler/vapochill/einbau1.jpg

http://www.techpowerup.com/reviews/Thermaltake/TWV500/images/120mm.jpg
Gray Mole
12-20-2005, 12:50 PM
Total combined wattage at 12v is 19.6 watts.

I'd recommend at least a 12v, 30 watt psu to make sure you've got the extra to compensate for load variations.

Gray
Gray Mole
12-20-2005, 12:52 PM
Sorry, you'd shown a pic of a .40 amp draw fan, but if you mean that the fan you'll actually use is .50 amp, then total load is 22 watts with heaters and fans.

Gray
sl4ck
12-20-2005, 12:55 PM
12v rail amp doesn´t matter??

Kind if i whant to use an old pc power supply
Marvin
12-20-2005, 01:19 PM
it is good to put a small charge on 5v ,like a resistor.
dward3
12-20-2005, 01:50 PM
You could run 12v AC adaptor from Radio Shack and plug it into surge protector.
The old PC power supply should work too.
sl4ck
12-20-2005, 02:45 PM
it is good to put a small charge on 5v ,like a resistor.

Could you tell me why? :)


The old PC power supply should work too.

what amperage should i have in 12v rail?
dward3
12-20-2005, 03:00 PM
your heating element and 2 x 120mm fans should take that much. Maybe, 2 or 3 amps to be safe. :)

edit: sl4ck, I bet 12v AC adaptor (1000 mA) would work in the US. I'm not sure about Portugal.
sl4ck
12-20-2005, 05:14 PM
we have 220vAC you have 110vAC. Maybe?

I'll use an old ATX PC PSU, any should work. Even a 200W PSU?:D
Gray Mole
12-20-2005, 05:43 PM
Voltage X amperage = wattage.

you got 12volts, you're set, you got 11.5v, it's different.

So if you need about 25w minimum, and assuming it's 12v exactly, you need 2.083 amps on the rail.

Make sure you got 3 minimum, but a 5 amp supply will ensure a long life.

Just remember that formula, and you won't need to ask, you can just work out what you need.

Gray
craig588
12-20-2005, 05:53 PM
it is good to put a small load on 5v ,like a resistor.

Fixed.
sl4ck
12-20-2005, 11:27 PM
Voltage X amperage = wattage.

you got 12volts, you're set, you got 11.5v, it's different.

So if you need about 25w minimum, and assuming it's 12v exactly, you need 2.083 amps on the rail.

Make sure you got 3 minimum, but a 5 amp supply will ensure a long life.

Just remember that formula, and you won't need to ask, you can just work out what you need.

Gray

Hummm, nice formula :) :banana: :banana:
Thx :)


it is good to put a small charge on 5v ,like a resistor.

Now, only need clarified about that :confused:
Why?
yngndrw
12-21-2005, 12:51 AM
Now, only need clarified about that :confused:
Why?

He ment that you should use a resistor on the 5V rail to load it, a 1/4Watt 10KOhm would be fine. This is just to balance out the loadings and to stabalise the regulation. It's just how these switching mode PSUs work.
Marvin
12-22-2005, 12:06 PM
that is it. The at and the ATX psus work different.