Need someone good with math involving watts and amps

[Utnorris]

So, I have a Lamptron fan controller that handles 45 watts per channel, how do I figure out how many amps that is? I am using San Ace fans rated at .52 amps each at 12v and want to use more than one on each channel from 5v to 12v. Can I do 2 or 3?

[jumper2high]

P = U x I
P - Power (Watts)
U - voltage (Volts)
I - Current (Amps)

So, at the best, you could draw about 3.75 amps at 12V before the controller would be officially overloaded.

[Waterlogged]

Amps x volts will give you watts. By my math, you can do 6 SA's per channel with comfort.

[Creekin]

this is elementary math/science!!!
WTF are they teaching you kids in school these days!?!?!?!?

[Utnorris]

Thanks everyone. I thought I could, but I wanted some "expert" opinions to verify my thoughts. I plan to run 3 - 6 fans on each controller for each rad.

this is elementary math/science!!!
WTF are they teaching you kids in school these days!?!?!?!?

Dude, haven't been in school a long time, a long time. I did however look it up, but I wanted to verify what I found instead of burning out a channel on the controller. So :P. LOL.

[Waterlogged]

this is elementary math/science!!!
WTF are they teaching you kids in school these days!?!?!?!?

Not everyone here is that young. I've been out of school now for 20+ years, and you do tend to forget a lot of stuff you don't use on a daily basis. I've forgotten a lot of the machining programming language I used to use since I haven't touched a machine since early '04.

[Creekin]

i assume the curriculum on Mars is a little diff to here on earth also..
do they even teach Ohms Law?

i would assume it would be "Marvins" law

[MagisD]

I spent a lot of time figuring this for my gt's, but with the wrong numbers. I had .84 instead of. 084. And was trying to figure out how to power 290 Watts in fans instead of 29 watts.

But you

.52a x 12v = 6.24 watts a fan.

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[MagisD]

i assume the curriculum on Mars is a little diff to here on earth also..
do they even teach Ohms Law?

Seriously Creekin do they teach manners where your from? All I ever see in your posts is snotty remarks.

Done with sidetrack lets leave it on OP.

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[Creekin]

20 years since i was at school too, and to be fair ohms law is about the ONLY thing i remember! and i spent the last 20 yrs as an electrician!

thank jeebus for google

[Panther_Seraphi]

Be careful thoug as a lot of fans have a huge spike in amps when they start up.

http://www.youtube.com/watch?v=f_27oS9kO4I

As you can see this noctua is drawing double the amps at the start than when its actually running.

I would say 4 fans per channel as a safe 24/7 maximum so you dont burn/blow anything.

[OldChap]

A word of caution on maxxing out a fan controller... measure the 12v current of each fan first if you can...Producers have been known to get it wrong sometimes in the blurb and printed on the fan.

[Creekin]

Seriously Creekin do they teach manners where your from? All I ever see in your posts is snotty remarks.

Done with sidetrack lets leave it on OP.

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Seriously MD you can't tell a bad joke from a snotty remark?
get out of wrong side of bed today? the guys location is MARS FFS!!!!
< see avatar

its 7am here, 3pm there maybe uve had a bad day and ive just woken up in a good mood..
until now...


i would agree 4 fans/channel max, thats what the numbers with my fans and aquaero equalled also.
good idea to test fan voltage first, very true it may not be 12v.

anybody got any hard numbers on start up current?

[MagisD]

A word of caution on maxxing out a fan controller... measure the 12v current of each fan first if you can...Producers have been known to get it wrong sometimes in the blurb and printed on the fan.

Send one to martin for testing :-) that'll give you real world numbers.

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[Tex707]

IMHO, calculating power with P=U x I is correct just in certain cases...and motors are not one of those.

[Utnorris]

Wow! Ok, first MD and Creekin, it's ok, I got it was a joke, which is why I replied like I did, so it's ok....

Now, I just tested out the FC-2, got it used, and apparently it's the first revision, so I have whine on the fans unless they are at max 12v, which is never going to happen. Theoretically, my koolance TMS200 controller should be able to handle 3 fans per channel and still be under the rated max by about 20-30%, but not sure if it will give me the same issue as the FC-2 did. I could just wire them all for 5v on a molex plug and leave it at that, but I like a little more control than that, so now I need to figure out whether I order 18 new fans or a new fan controller. Hmmmm, decisions, decisions.... New toys or be practical?

[Creekin]

new toys wins everytime!
this is the internets! leave your logic and practicality IRL!

Tex is right, as a lighting tech, i know lighting loads are easy to calculate, but motors are a diff story and the usual equations don't suit
not sure what the right equation is though
any electric motor techs?

[MagisD]

Wow! Ok, first MD and Creekin, it's ok, I got it was a joke, which is why I replied like I did, so it's ok....

Now, I just tested out the FC-2, got it used, and apparently it's the first revision, so I have whine on the fans unless they are at max 12v, which is never going to happen. Theoretically, my koolance TMS200 controller should be able to handle 3 fans per channel and still be under the rated max by about 20-30%, but not sure if it will give me the same issue as the FC-2 did. I could just wire them all for 5v on a molex plug and leave it at that, but I like a little more control than that, so now I need to figure out whether I order 18 new fans or a new fan controller. Hmmmm, decisions, decisions.... New toys or be practical?

I keep buying fan controllers, my wife said if i say i need to buy one more she's slapping me. Lol picked up a nxzt LXE.

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[Creekin]

my wife said if i say i need to buy one more she's slapping me. Lol picked up a nxzt LXE.

sounds like your revealing a bit TMI about your personal life MD,
like a bit of slap and tickle eh?

p.s. that was a Joke mate

[jumper2high]

IMHO, calculating power with P=U x I is correct just in certain cases...and motors are not one of those.

They are correct if you're calculating it for the purposes of determining a load on the fan controller.

[zalbard]

I spent a lot of time figuring this for my gt's, but with the wrong numbers. I had .84 instead of. 084. And was trying to figure out how to power 290 Watts in fans instead of 29 watts.

Haha, this is brilliant!
Would be enough for a small helicopter!

[Utnorris]

Well, I think I am going to try and see if the Theoretical load capabilities of the TMS200 are correct, worse case is MD sends me one of his extra fan controllers, .

[Creekin]

please video it so we can all enjoy the fireworks!

[MagisD]

Only spares i have is a half burnt out kaze master and a fc-2 revision 1 with first port blown.

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[antiacid]

Seriously Creekin do they teach manners where your from? All I ever see in your posts is snotty remarks.

Done with sidetrack lets leave it on OP.

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shush, Creekin made fun of a dude who should've used 5min on google. Case closed.