DIY fan control ? . howto?
- Thread starter ComradE_BeaN
- Start date
- Status
hyeah: I use zener diodes, they're totally simple to use.
I simply connect a zener in series with the positive of the fan wire, cover the whole thing with shrink sleeving and I'm done.
A 5.1V zener drops a 12V line to 7 volts, and a 3.3 zener drops it to about 8.7 volts. Some fans don't like the 3.3, but all of them work perfectly with the 5.1V.
Of course you can get 7V by tying the fan positive with the +12V line and the fan negative to the +5V line. Oldest trick in the modder's book. A single molex does this trick fine.
I simply connect a zener in series with the positive of the fan wire, cover the whole thing with shrink sleeving and I'm done.
A 5.1V zener drops a 12V line to 7 volts, and a 3.3 zener drops it to about 8.7 volts. Some fans don't like the 3.3, but all of them work perfectly with the 5.1V.
Of course you can get 7V by tying the fan positive with the +12V line and the fan negative to the +5V line. Oldest trick in the modder's book. A single molex does this trick fine.
i went to sp road today...got 2 5W pots...some cheap thing..
i couldnt even find a proper good looking one atleast..
Anyway..both got burnt out within 2-3 mins...lol..
have mailed the pankaj electricals asking their bangalore retailers....lemme see wat reply i get..
__________________
i couldnt even find a proper good looking one atleast..
Anyway..both got burnt out within 2-3 mins...lol..
have mailed the pankaj electricals asking their bangalore retailers....lemme see wat reply i get..
__________________
dont use the pots with the knobs towards either of the extreme positions , thats what's causing them to burn out.
PS: want to learn a li'l electronics DIY? this seems like a great way to start learning electronics
Speed control for brushless fan
its a straightforward circuit ......wouldnt take more than a day and 50 rs
PS: want to learn a li'l electronics DIY? this seems like a great way to start learning electronics
Speed control for brushless fan
its a straightforward circuit ......wouldnt take more than a day and 50 rs
super_saiyan said:
Good looking is secondary, since they're to be installed inside. What Ohms rating did the pots have? How much'd they cost? What is your fan amp/wattage rating?
5W should NOT burn out so quickly, did you connect the wires correctly? i.e the red fan wire should be cut in two, the end coming from the MOLEX should be soldered/connected on the left pin (assume the pot is facing towards you and the pins are at the bottom) and the end going towards the FAN should be connected to the middle pin - that way, when you twist the pot from left to right, the fan speed increases.
this is wat i did..:/..
anything wrong? ..
btw..i'm doing this with a secondary psu..lol!..not connected to main pc yet..
greenhorn said:
Yes, 4.7K will never serve the purpose and the fan will work only in the extreme position of the pot with no speed control. Further, the fan is 0.72A and so the wattage is 8.64. Moreover, from the appearance the pot seems carbon and not wire wound, though not sure.
BTW, my Vantec stealth 92mm fan's power input is 0.84W.
As they said, the value is too low. The pot will be much bigger than this one. Also, in the pic, the middle is fine - input needs to be on the other side (provided you need the fan control twist L ---> R) Your current setup is R ---> L .
That fan seems to be pretty power hungry!
That fan seems to be pretty power hungry!
BIKeINSTEIN
Herald
AK3D said:
That's why i asked how heavy.
Most 'medium to highspeed/ultra high speed/extreme high speed' NMB/Panaflo/Delta fans that need speed control will be rated 5W and upwards.
Anything slower is too slow to need a controller.:rofl:
That's all i have learnt while window shopping at sidewinders and other places.:ashamed:
janitha said:
the shop i bought from was having 4k7 & a 10ksmthing..& a 100k one..
which one is better? .. :ashamed:
damn,,,those trips to sp raod..
..& panjak has not replied to my yet..
.. & somehow i am not surprised..:lol:No, you won't be able to use either 10K or 4.7K.
Seriously, get the zener. It's a fixed voltage, and will be much less of a headache. For that current rating you will need a 5.1 volt, 5 watt zener. That will be able to handle a current of 1 amp. Will get really hot, but should still operate fine.
Or just 7-volt the fan. in my earlier post. Don't use a pot, the fan is too powerful for it.
Seriously, get the zener. It's a fixed voltage, and will be much less of a headache. For that current rating you will need a 5.1 volt, 5 watt zener. That will be able to handle a current of 1 amp. Will get really hot, but should still operate fine.
Or just 7-volt the fan. in my earlier post. Don't use a pot, the fan is too powerful for it.
Greenhorn, that's a pretty complex circuit for anyone to build, plus there's not enough current gain to run 720 milliamps of current from that transistor.
The same thing can be achieved with two transistors and a small pot, but I'm not sure you need something even that complex, when there are better and simpler solutions, achievable with one or two solder joints.
The same thing can be achieved with two transistors and a small pot, but I'm not sure you need something even that complex, when there are better and simpler solutions, achievable with one or two solder joints.
i was like..wondering to do some cheap mod to switch to full speed & variable whenever required...
right now..i'm using a 3way switch..connected to 12v & 5W on each ends..lol
right now..i'm using a 3way switch..connected to 12v & 5W on each ends..lol
super_saiyan said:
And why is that not good enough?
AK3D - it doesn't matter what the control element is, if you need to drop 5 volts at 720 milliamps, any element in series will dissipate the heat - so will a controller transistor or pot. The only way to avoid heat is by the 7volt method.
But I do agree that given the nature of the OP's experiences with pots and his ability at letting the magic smoke out, a ready-built converter would be the best option.
If ready to spend about 2K, I think it will be better to buy one CM Aerogate II or III. It is available with online stores like theitdepot.com and theitwares.com.
Cooler Master
TheITWares - Cooler Master
IT-Depot
Cooler Master
TheITWares - Cooler Master
IT-Depot
Thats the correct way to do it. Keep adjusting the pot to the extremes and try it. The fan should be at full speed on one end and not spin at all on the other.
Raghu.
Raghu.
- Status