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?
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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?
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.
Amps x volts will give you watts. By my math, you can do 6 SA's per channel with comfort.
this is elementary math/science!!!
WTF are they teaching you kids in school these days!?!?!?!? :confused:
:p:
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.
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.Quote:
Originally Posted by Creekin
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.Quote:
Originally Posted by Creekin
i assume the curriculum on Mars is a little diff to here on earth also..
do they even teach Ohms Law? :D
i would assume it would be "Marvins" law :lol:
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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Seriously Creekin do they teach manners where your from? All I ever see in your posts is snotty remarks.Quote:
Originally Posted by Creekin
Done with sidetrack lets leave it on OP.
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20 years since i was at school too, and to be fair ohms law is about the ONLY thing i remember! :rofl: and i spent the last 20 yrs as an electrician!
thank jeebus for google :D
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.
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.
Seriously MD you can't tell a bad joke from a snotty remark?Quote:
Originally Posted by MagisD
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?
Send one to martin for testing :-) that'll give you real world numbers.Quote:
Originally Posted by OldChap
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IMHO, calculating power with P=U x I is correct just in certain cases...and motors are not one of those.
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?
new toys wins everytime! :D
this is the internets! leave your logic and practicality IRL! :p:
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?
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.Quote:
Originally Posted by Utnorris
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sounds like your revealing a bit TMI about your personal life MD,Quote:
Originally Posted by MagisD
like a bit of slap and tickle eh? :D :rofl:
p.s. that was a Joke mate :up:
They are correct if you're calculating it for the purposes of determining a load on the fan controller.Quote:
Originally Posted by Tex707
Haha, this is brilliant! :DQuote:
Originally Posted by MagisD
Would be enough for a small helicopter! :rofl:
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, ;).
please video it so we can all enjoy the fireworks!
:explode2::D
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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shush, Creekin made fun of a dude who should've used 5min on google. Case closed.Quote:
Originally Posted by MagisD
This forum is one of the best (if not the best) for sharing knowledge amongst members. We all have different skill sets/training and remember different things from school so it is nice to be able to share that with each other. Asking a question should never be an offense on this forum. Questions asked, no matter how simple to "Google", start up a conversation that can go in many different directions and open up areas of thought that Google can't.
So the next time someone asks a question here, please show them and the world that Xtreme Systems is not the run of the mill forum, here knowledge is taken to a higher level and manners still mean something. :up:
P= Power (Watts)
I= Impedance (Amperage)
E= Electromotive Force (Voltage)
P
_________
I | E
P = I x E
P / I = E
P / E = I
No, look back through Creekin's other posts. He talks about the US being "illiterate" as well as just makes immature, snotty remarks in almost every post he makes.Quote:
Originally Posted by antiacid
Lets grow up, children.
Bud take it easy. It's not that easy to calculate. Every fan has peak current when is turned on so that's why it's uses more power. So you can easy burn your fan controller. Most of controllers have over current protection but for 24/7 use sometimes is not good to use them on their limits. So there is no reason for anger.Quote:
Originally Posted by antiacid
His fan controller probably has a peak current rating as well. Look at the datasheet of any power transistor or fet. they have peak ratings as well.Quote:
Originally Posted by skeyo
If the OP wants to get technical, try to find out the transistor/fet that is used for the each channel of his fan controller, and find the datasheet. The fan controller manufacturer might just underrate their max current rating. never know, unless you look at a datasheet ;p
The way I was taught...
W= Power (Watts)
I= Current (Amperage)
V= Electromotive Force (Voltage)
R= Resistance (ohms)
W
_________
I * V
W = I*V
W/I = V
W/V = I
then there was the resistance triangle too
V
_________
I * R
V = I * R
V/I = R
V/R = I
Over the years here in UK they have messed with the education system loads
It would not surprise me if this kind of info is missed off the curriculum entirely
Just by the way all you FAN boys ...when you put a fan in open air it will pull a lower current than when you put it on a rad. If you want to demonstrate this lay your fan on the bench blowing down and measure the current then do the same standing the fan in free air. Ok so it is not huge but it is different just the same...The higher the density of rad finnage the higher the current will creep
Anyone know if there is a mod for the original Lamptron fc2 to stop the induced motor noise?
Hammer? :shrug:Quote:
Originally Posted by OldChap
I apologise if you misinterpreted my comments,Quote:
Originally Posted by BeepBeep2
I made no allegations about US literacy, for the record it is 99%, same as here in Oz, and for the record, I don't give a flying banana about your literacy or
lack thereof, nor anything else that happens in Sarah Pallin land for that matter. :p:
As for my "snotty remarks" :rofl: , It is not my problem if you don't understand my sense of humour.
Your choices are A) Laugh B) Ignore C) Take offence
My 1st comment in this thread, may have been misinterpreted by some, as I neglected to end with a :p: as intended. This oversight has now been corrected, but I note that the intended recipient got the implied joke anyway.
The OPs Q06:47 AMQuote:
Originally Posted by Utnorris
Can,and was answered with 2 mins on google.
06:49 AM
The OP did his research but also wanted to ask the opinion of his peers to confirm. Thats what forums are for!Quote:
Originally Posted by jumper2high
The question had been answered well, TWICE when I came along, so all that was left for me to do was make lol's :D
If YOU take offence to someone else's comments and want to make an off topic comment, use PM. I would for this also, except for the fact I have the right of reply.
Back OT
You never want to run gear at its capacity, especially if its on 24/7
Going by Wl's math of 6, I would run no more than 3 per channel, that is my plan for my Aquaero also, and i have seen channel wattage specs for it ranging from 5w per to 25w per! (I know my AQ4w/powerbooster does 25w on channel 1 and 15w on 2-4.)
if you don't go over 50-75% of the theoretical load limit, you shouldn't have a problem with start up current or overloading.
Good point Diverge, BUT, even if the tranny can take a bigger load than the channel specs, doesn't mean the rest of the circuit can! pcb,plug pins,cabling.Quote:
Originally Posted by Diverge
In my experience of lighting loads, the plug pins are usually the weakest point in the circuit. I have spent YEARS replacing pins in 10 pole wieland plugs! :mad:
That's the same way i was taught OldChap :) but we're OLD! :p:
All they teach these young whipper snappers is how to type "g o o g l e" :rolleyes: :p: :rofl: :D :shrug:
Good idea WL! :up: :rofl:
leaving comments aside and going back to topic:
as i'm currently in the process of building my own fan controller, i doing some math for selecting the correct output transistor.
the goal is to keep the power dissipated by the transitor in focus and not the total power the fan will use. if the fan is running at full speed (at 12V and draws about 1A) the transistor needs to be able to run the full current, but it will drop just something below 1V, thus needs to be able to dissipate less than 1W!
the story gets interesting when the fan is running at half speed which might be at 6V and in this situation the fan is drawing about 0,5A. you can see it coming: the transistor needs to drop 6V off the 12V supply to feed the requested 6V to the fan. at this time the transsitor dissipates about 6V x 0.5A = 3W.
as you can see, running the fan at full speed is not the point to take care of!
anyway, in any case we are far away from the advertised 20W, 30W or even 45W a fancontroller is able to control.
even the increased power draw during startup, should not be that much of a problem. its very likely the transistors used are able to handle a magnitude of the required current the fan will draw at startup. especially if you take into account, this will last just for fractions of a second in most cases.
this all holds true for so called linear voltage regulation!
coming now to your lamptron. as far as i know the lamptron is not utilizing linear voltage regulation but using PWN control instead. which most fancontrollers are as its the cheaper solution. when running in PWM mode, the transistor is by far NOT stressed as in linear mode. think of switching the fan on and off rapidly within a certain time interval, eg, 10sec: if you switch it on for 3sec and off for 7sec the fan will get only 30% of the energy it would get when it is switched on for 10 sec. thats pretty much what PWM control is about.
the transistor has to dissipate much less power as it is either switched off
current is 0A thus dissipated power is 0W
OR
switched on, where current might be 1A but voltage drop is far below 1V which gives a dissipated power of less than 1W
did some experiments with PWM control myself, but unfortunately the circuitry needs to be tuned for a certain powerrange of fans.it worked seemlesly with some fans but did not work at all with other fans. either the circuitry is designed to control standard case fans or it is designed to control powerhungry fans like some deltas, but it most likely wont be able to control both of them!
also the base frequency used in PWM control is an important factor. low base frequency let you control a wider range of fans, but has the disadvantage of generating this ticking and annoying sound and also prevents correct rpm readings at lower speeds.
to make a long story short:
powercapabilities of fancontrollers using PWM is more or less a marketing gag. if PWM is working as expected you want run into a problem here.
this is different for linear voltage control, but as stated above, the power used by fans is much overrated.
here is an example of a delta fan (the most powerhungry fan martinm210 recently tested. look at the figure:
fan voltage / dissipated power in the transsistor (linear voltage control)
5V / 1.7W
6V / 2.1W
7V / 2.2W
8V / 2.1W
9V / 1.9W
10V / 1.5W
11V / 1.0W
12V / 0.4W
as you can see, the most demanding range is 6V to 9V but the total power dissipated is still just above 2W and far away from the advertised limit of most fancontrollers.
the advantage of linear voltage control is, it will work for all fans without the problem of this ticking sound but at higher cost. also rpm readings will work almost the whole rpm range.
when you are in search of a fan controller i recommend to look for one which is not working in PWM mode.
will keep you posted somewhere on this forums how i proceed with my own project and findings regarding fan control.
Ok, so just for the record, I did not take any offense, hence my response, I can give as well as take unless it gets personal and then I hit the "ignore" button. It was not my intention to start a flame war, just ask a simple question. Yes, I could have just relied on Google, however I like to get more info than what is posted by who knows on the internet. I had two conflicting sources of info, so i wanted to verify, no need to have a fire even if the system is water cooled, not my idea of fun.
Anyway, I have gone back to what I was doing previously and running 6 of the San Ace fans off the Koolance controller and 3 off a 5v converter board. Not what I wanted to do, but i can't seem to find a decent fan controller for 18 San Ace fans.
Anyway, this thread looks like it should be closed based on the comments. For those that gave advice, thank you, for those that did not, it's ok, no harm, no foul.
i doubt you will find any one controller that can run 18 fans, why not just use 2 fc5's or something?
do u need to control them? if not just hard wire the lot :D
which san ace are u talking about, 9G1212H101?Quote:
Originally Posted by Utnorris
took currentreadings from martinm's tests again and come to a max power dissipation of less than 1W for this san ace! dont think this is a real problem for a correct constructed fan controller .
i need a fancontroller for my build anyway. so i will build one for sure!
would recommend you run the system as described for now. may be i come up with a solution within the next two month. otherwise you can still look after a fancontroller with the requested capabilities after this time.
pm me if you have further questions ...
SWC, among others, sell a rheostat (variable resistor) or two that might just do the trick for a lot of fans (probably not all 18 though) and do it the old fashioned way by inserting resistance in the circuit. This will dissipate power too so might be best mounted in a position where there is airflow but I would venture that for your immediate needs, Ut, it would resolve the problem. Big (high power) versions have little use these days though and will therefore be less common and more expensive....probably $30 or more
The only one I have found was the FC-2 that does over 30 watts per channel. Assuming the calculator I used is correct, I need 6 watts per fan, which comes out to 108 watts, however that would be on one channel and I figured I could run 6 per channel on the FC-2, so that would be ok. The problem is the whine it produces. They did redesign it with digital vrm's, however it's hard to tell who has the new one and who has the old one and even then there is no guarantee it won't make the same whining noise with 18 fans connected to it. I could do two controllers, which I may end up doing, but I was trying to keep it simple. I would just hard wire them all at 5v, but I would rather have the ability to adjust the voltages. Anyway, any suggestions would be welcomed.
45 W per channel would be 45/12=3.75 amps, however I got to warn you if your running at max draw your going to be running into problems of a different sort, you'll be creating heat!
Also I assume this controller uses some sort of digital PWM to control the fans and yes that can cause a whine if it's not properly capacitor'ed at the output. ( properly sized capacitor and a diode to prevent chargebacks into the controller is a must for any fan controller that wants to avoid the whine factor. Zahlman fan controllers used a method that created alot of heat but avoided the whine (this was the first commercial single fan controller) that allowed tach signal pass through.
the start-up factor could also be alleviated by using a smoothing capacitor. however if 45W is the max per channel you should use no more than about half of that for daily use (i.e. no more than 4 fans per channel and that is pushing it)
the problem with fan controllers is that they tend to design them to spec, to save money hence they usually dun spend the extra money for a good really oversize smoothing cap.
so some noise tends to get through.
just one question though WTF do you need 18 fans I'm right now designing a new case and it will have 5 fans 3 in the water cooling compartment, two in the main board compartment.
there comes a time when more fans are overkill.
Directed airflow would get you better results.
well good luck
terramir
Why 18 fans? Because I have 60 or so San Ace fans sitting around and figured why not. And this is xtremesystems, so there is no such thing as overkill. :D
ok, so better question then
WhyTF do you have 60 fans!??!?! :confused:
and more importantly..
SHARE ya bastard! :D
why not use all 60? :rofl:
FYI, You might consider some sort of PWM controller option instead. I haven't tested it yet, because I can't figure out how to run one without a computer, but according to Bing on OCN, PWM is better for the big fans for reducing motor noise. You might check with the gurus over at crystalfontz, their forums are generally pretty helpful.
Ehhh are those the 127x38 fans or the 120x25 ? aluminum frame or plastic?Quote:
Originally Posted by Utnorris
these are like classics if there the ones I'm thinking of.
I could use five or six for a project if they are the ones I'm thinking of
terramir
They are 120x38mm, model 109r1212h1011, the ones they do not make anymore.
Isn't the new fc-t pwm?
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Hmm you willing to part with 6 of them and well how much for the 6 PM me pleaseQuote:
Originally Posted by Utnorris
terramir
That's what we heard, but after watching this video, @3:33 it clearly show Voltage as an indicator option.Quote:
Originally Posted by MagisD
PWM doesn't operate at lower voltage, so I'm lost...:shrug: As far as I can tell it's voltage controlled.
Actually PWM does operate @ a lower voltage (not really but bear with me)Quote:
Originally Posted by Martinm210
what PWM does is either switch it on or off so on the axis of time you have a bunch of 12 states and a bunch of 0 volt states, now if you capacitor filter that output sufficiently Before the capacitor you will see a bunch of 12V states and a bunch of 0V states, but on the other side of the circuit where the filter capacitor is you will see an average voltage that can be anywhere from 0 to 12V.
Let's say the 12V is on 75% of the time hence 0V is on 25% then the voltage after the filter capacitor should be around 9V if you use a filter cap that is too small you will get spikes in that voltage (that's where the humming comes from in some pwm controlled fans). Now let's say 12V is on 66.6% of the time then you'll get about 8V after the filter I think you see where I'm going with this.
So while the PWM circuit IS a 12V circuit because of the charging curve of a capacitor the voltage that is output is lower than 12V, there is also another danger, if you design the filter capacitor to high then it will take a long time for the voltage desired to be reached, however; unless you use one that is way over sized the delay should be no more than a few seconds. There is a way around that though. You measure the voltage after the filter cap and base the on off cycles on this voltage. So it will start basically always on till it reached the desired voltage.
terramir
Interesting, thanks for sharing:up:Quote:
Originally Posted by terramir
So, in essence, the fan will see voltage control, but the controller is converting 12V to a lower voltage through PWM + Capacitor?
The advantage of this is simply not generating heat in the controller?
Sorry for the dumb questions, just trying to get at least a little pinky around the topic. I've had a few people indicate on my 38mm fan tests that the problem is lower voltage, and PWM is the better way to go....yet it sounds like this controller is converting PWM to lower voltage. Why not leave it PWM if PWM is better?
Because some analogue, not pwm fans might get extra noise under pwm regulation. IIRC In normal 4pin pwm fan there is separate wire for pwm synchronisation, that solves that issue, but with analogue fan with normal 3pin these voltage spikes might differ at different rpm at which point coils should actually charge and push to turn rotor and at one position have more voltage, at different less, so possibly resulting in that extra noise.Quote:
Originally Posted by Martinm210
Otherwise pwm of course is better then analogue regulation in several ways - it's circuitry is cheaper, as doesn't require monstrous heatsinks to dissipate redundant power, it can handle much higher current, with pwm minimum rpm-s can be lower (as less of a problem minimum startup voltage to start turn motor, because it's always full 12V or 0V). But probably because that pwm rpm regulation is newer, and many analogue fans/pumps exist, some choose analogue regulation as safe bet for everything. (eg. Aquaero).
Thanks!
I'm going to play around with my custom 4pin PWM controller vs Kaze Master vs direct variable PSU. So far I can't tell any difference between the Kaze Master and PSU with my subjective listening tests, but I haven't done anything really controlled yet either.
Maybe it would even be worth adding a separate capacitor after the fan controller to help stabilize the voltage?
Yes less heat, but not no heat, there are always some losses.Quote:
Originally Posted by Martinm210
see below on the PWM question
This noise thing can be solved by properly choosing the capacitors for the output, however the problem is that different kinds of fans will create different kinds of induction noise (electrical noise) hence choosing the right filter capacitor, unless you over-design (which is more expensive) is difficult, when designing a generic fan controller. To really do a fan controller well you would either need to do two things, A. limit the voltage to about 11.1V max usually it's about 11.3V-11.6V why the lower voltage, because you would need to add a shottky diode and another filter capacitor in order to prevent induction noise from messing with the controller and eliminate voltage spikes.Quote:
Originally Posted by churchy
Or B. Design a controller that works well with a specified tested limited range of fans
My $.02
terramir
Martin, don't be confused with the term of PWM, in your case, DO NOT put any capacitor on that custom PWM "SIGNAL" controller of yours, cause the signal generated intended to be sharp and going to be fed into the fan's PWM signal IN wire, adding capacitor will ruined the signal. And this has nothing to do with the "powered" pwm that is used like that Kaze Master or other 3 wires fan controller.Quote:
Originally Posted by Martinm210
While for Kaze Master, I assumed its using PWM switching power design, this is different animal, although it has the word "PWM" ;) , its the internal working circuit mechanism to to lower the voltage for supplying the fan efficiently compared to other low efficiency circuits like using linear method such as using transistors, linear IC or the classic using rheostat (high power pot)
For these type of controllers, adding capacitor might smooth out the ripple, although I doubt it will make any huge different since the switching frequency inside the power switching circuit might be very2 high beyond human range, prolly above 50Khz, depends on designs.
When undervolted, under certain conditions and certain fans, they don't react well since the internal circuit was reaching the minimum threshold of their normal working voltage, that condition sometimes will create the oscillation that making those ticking noise when undervolted.
An old but still good reference on controlling DC fan -> Why and How to Control Fan Speed for Cooling Electronic Equipment , just skip and scroll to the bottom if you don't understand the tech jargons, and jump at the summary section.
as said before, when i played around with PWM control i ran into the problem of sizing this output capacitor (cap). as someone posted before, by using such a cap (and probably an inductor) you can convert the PWM signal to an analog voltage. if the cap is too small the cap's charge wont be able to hold the voltage for the supplied load and will have almost no effect. if the cap is too large, the cap will be loaded during the PWM pulse but wont be discharged completely by the load during the PWM pause. this results in a limited control on the lower PWM range (e.g. PWM 0%-20% results in 9V-12V, everything above 20% = 12V) and that's the issue i ran into. the cap needs to be sized correctly for the individual load to get full range rpm control!
the internal circuitry of some fans prevents them from working well on PWM.
i have some nzxt fans reacting well to PWM but i also have some sflex which have very limited control when used on PWM.
almost ever you will get erratic rpm readings at lower rpm as power to the rwm reading circuitry is switched off and on periodically at the PWM frequency which overlays to the rpm signal itself.
PWM frequency also plays a role here, this is the frequency at which the PWM signal is switched on an off.
as mentioned before, this ticking sound comes from the fan periodically switched on and off. if PWM frequency is in a range above the frequency we can hear, above 20kHz (which is also intels spec) the ticking sound problem goes away, but unfortunately lower PWM frequency works better in controlling the fan speed than higher frequency does at least with the fans i tested here.
to me using a more costly and inefficient analoge (or linear) voltage control circuitry is the way to go. i don't really care about this additional one or two watts per fan when the whole system burns hundreds of watts already. i like the idea of PWM and
- yes it will be more efficient, thus produce less heat
but if it
- does not allow me to control all of my various fans
- prevents rpm reading at lower speeds
- makes this ticking noise
its of no use to me.
this all holds true for 3-wire (non PWM) fans only as 4-wire (PWM) fans already have their own PWM controller with their own switching transistor built in and use the PWM signal supplied on the fourth pin just for controlling the built in switching transistor.
martinm, as posted by bing: your controller is just generating the control signal of 4-wire (PWM) fans for their built in circuitry with its own switching transistor. the cap we were talking before is the output cap behind the switching transistor where you have no access to.
There is another way to do that not quite pwm but close it's called a linear switching regulation, While I was writing the post I thought of a simple regulator, and posted it to my electronics lists. With this it's not about frequency the current is switched on and off depending on capacitor charge level, with this you should be able to get 5 volts or less and the switching should not effect the fan at all as long as you dun mind the fans running for a few seconds longer after your computer is turned off. this is doable just waiting to hear back from a few and get a few more inputs to figure out which parts I will use. should work and with a PTC I might be able to even temperature control the fans. calculations are necessary but it could be doable. , Heck I might even use a comparator or an op-amp to make this a reality, but I want to keep it fairly simple.Quote:
Originally Posted by fgw
I really dun like those 4 pin fans cause they tend to cost more, and do their own thing. A few two or three pin fans should do nicely though.
terramir