Hey, fellow TekSyndicate members. I was just installing a new (old) fan to my computer from my garage, and since it spins at 2500 RPM, it is VERY noisy, and it sucks up a lot of power, and I actually had to remove another fan that wasn't very significant in order to keep my CPU stable (the current overclock didn't have enough power). It's 120mm. I know that the three pins are positive (red), negative (black), and current speed monitor (yellow), but there is obviously no speed control. So, because of this, I wanted to investigate further. Is there some sort of program that can change the actual voltage being put into the fan to slow it down? Or perhapse an actual peice of hardware with a fixed resistor or dial of sorts to manually lower the voltage? This is probably silly to ask, but I am really just curious. Thanks everybody!
yes there is a piece of hardware. it is called a fan controller most use dials or buttons to change the voltage going to the fan plugged into it. uses a molex power connector and splits it off into 3 to 6 fans depending on the model.
No, if you lower the voltage you will slowly degrade the motor until it cant work anymore.
A fan controller will lower the ampreage going to the motor, its the same power just not as "intense". Keep in mind voltage is like they type of power the motor needs and amps would be the strength . Just a very basic/rough explanation. And your wires would be positive, negitive, and ground.
Also if you go the fan controller route I wouldn't recomend the bitfenix recon mine keeps thottleing the fans its annoying. Another thing you could do is just get a noctua fan, probably cheaper then the controller and they are near silent at full rpm with leading airflow and static pressure.
No, lowering the Voltage wont degrade the motor in any major way unless your running it well below its start voltage or above its rated voltage.
Oh and the Fan controllers change the Voltage going to the fan and thats how the speed is controlled, Hence the Voltage settings on some an Inline Low noise adapters which also drop the voltage.
If you are looking for total silence i would get some better fans as mentioned above and either a fan Controller or make sure the Fans are PWM so they dont spin up unless it starts getting toasty.
http://ecmweb.com/design/highs-and-lows-motor-voltage
Im an electrician and I shit you not. Dont mess with voltage on that motor if you want to use it for any length of time. A high end fan might be able to handle different set voltages like the noise reducer but then again i wouldnt say it lowers voltage (even though they are labeled so, maybe i'll have to grab my volt meter). Its a huge misconception everyone thinks volts means overal power but its amps.
Ohm's Law says voltage is current times resistance, so if a fan controller adjusts the amps then wouldn't it also affect the voltage also?
I always that that fan controllers just used a variable resister to lower the voltage the fan receives to slow the speed.
Well first off Overall Power, as in energy is regularly measure in Watts, not amps, and watts are calculated by multiplying amperage by voltage e.g. 1Ax12V = 12watts of total power.
As what your talking about the Electric motors, Pushing the limits of any motor will degrage is MTFB and the like, but Case fans for computers have different ratings that they are designed to operate in.
A lot of fans can use anywhere from 5-12v and some can even use anywhere from 4.5-14v depending on the Motor used, so no it wont adversley effect the lifespan of the fans, which by the way usually have an MTFB of 50,000-100,000 Hours so any small degridation in the lifespan, say 1000 hours, represents a very small percentage of the lifetime of the motor.
To add to all of this that Article is talking about 230v Motors with Heavy Loads, which also requires more power to start, where a deviation in the Voltage being applied could cause more degridation of the motor if the load is hard to start, It even says right in the article
"On lightly loaded motors with easy-to-start loads, reducing the voltage will not have any appreciable effect, except that it might help reduce the light load losses and improve the efficiency under this condition."
Also, why did you think they use or should use Amps ? Using a higher voltage is more effecient and also easier to regulate than using Amps with a constant voltage. This is why most Electrical Appliances and motors are regulated using Voltage and the Amps are then drawn as needed to make up the Energy needed for whatever load said Appliance or Motor is under.
This is all very useful information. I'm looking at some new cooling systems for my computer, bacause the out take fan that I have is starting to die as well. I might justend up gutting my case and starting from scratch with a new PSU and motherboard, and probably an i5 processor as well. There are definitely some fan controllers that I could get as well, but I might just stick with programs like Speedfan. Im not too worried about destroying this fan, as I have plenty of others of the same type, but like this one, they are power suckers and will require more power than my PSU can currently handle. Anybody think that the bios for my system can help with this? I haven't messed with any voltage settings, as I dont want to fry anything, but could the over voltage settings help at all? My board is an Asus P5KPL-CM running the latest bios version, and if anybody has anybosy can help me out with this it'd be great.
You have some very good arguments but I'm looking at my noctua nfa-14 flx and it says 12v (no + or -) just that it takes plain 12v DC and doesn't say an amperage. That just says to me any other voltage is bad news and the amperage is the variable but i realise im being limited to what the brand deicides to tell me. Im not saying your wrong as I usually deal with industrial electronics and pc is not my expertise but thats just what makes sence from my point of view.
I see what you mean. Maybe the fans themselves are what matters in whether you can change the voltage or amperage. I'll mess around with some other old fans I have in my garage.
From the admittingly brief research I did on your board it looks like only the cpu fan is controllable in the bios via Q-fan (?). So it looks like speedfan is a good choice if you got that working. Or the next step would be those low noise adapters or fan controller.
Either buy a new board that has 'fan xpert 2' ~ asus p8z77 etc It'll control every fan connected to the board from 3pin to 4pin.
Just use voltage reducers dude. Some fans have their min voltage requirement though so check.
As for degrading the motor???>>Im with BeyondNight on this one 100%>>I have and have always had my 12v fans running at 7v or 5v (on my radiators). Not one has ever died... Ever... Most are close to 6 years old now. Still fine.
Most decent fans come with voltage reducing cables as well like noctua. And in most Antec cases the rear fan and or top fan has a voltage reducing swith (lo, med, high) And even if a fan did burn out after a year or so. ??? Who cares, they're like $20.
The electrical energy needed to make the fan turn is a given, at first, to start the fan up, a higher amount of energy is needed to compensate for the inertia. Once the fan spins, the inertia actually helps the motor and less energy will be needed. A fan that spins slower, generates less inertia, so when the workload is slightly variable (and it is because a pc case is not a laminar flow), it will proportionally need more added energy than a fan that is spinning at a higher rpm.
When a fan is controlled by either a fixed voltage or a variable voltage control set to a certain value, and the fan starts, it will draw extra current (ampère) when it needs more electrical power. The fact that the fan starts at that voltage, means that the electrical motor is perfectly within normal operating parameters, it will not be damaged at all. If the fan doesn't start, and still electrical energy is applied, it will not operate normally, and that may damage the motor after a very long time of using power without effect. It's clear that a fan that is undervolted and spins, draws no more current than to dispose of the energy required for the normal operation of the fan, so there is no problem. It's also clear that a fan that is undervolted and doesn't spin, will draw a maximum amount of current in order to try to function, but will not succeed. How much current? Hardly more than a normal operating fan, but enough to damage the motor if it's left in that non-spinning but electrically fed state for a couple of years.
Conclusion: undervolt your fans till they do what you want them to do, but don't go under the voltage required to make them start to spin. Pretty much all operational conditions (dirt, magnetic influence, mechanical damage, overvolting, etc...) will take out your fan long before it breaks because of any undervolting, which doesn't mean undervolting in certain circumstances can't damage the fan's motor.
Now to get back to the essence: 4-pin fan: PWM controlled, don't undervolt it but get a digital fan controller like a T-balancer; 3-pin fan: voltage controlled, don't control it with a PWM controller unless the specification of the fan explicitely states that it's PWM compatible, or you will kill the fan.