Pacify Your PC - Part 2: Where's the noise?

[Hicks12]

Sorted the gfx card issue now nick , evga precision tool=win over nvidia tools/rivatuner. Now just the power supply.....

[TAKTAK]

That's what those little resistor thingies were for.

i thought they were for the three pins?

http://www.quietpc.com/gb-en-gbp/pro...ries/resistors there for 3pin fans.

a 4pin molex connection would need the volt mod by changing the molex pins around a little bit which is still very easy to do TBH.

[Nick]

Ahh sorry bud, I didn't read your post properly, you're quite right.

Maybe we can get the Quiet PC guys to do molex ones?

[TAKTAK]

Ahh sorry bud, I didn't read your post properly, you're quite right.

Maybe we can get the Quiet PC guys to do molex ones?

hmmm, would certainly be possible to just produce a little convertor to do it quickly..

so you just have a short male-female molex cable with the pins re-arranged that you just connect up (for some unknown reason i have a little molex cable that i just keep dismantling, on my desk )... but i suppose it could be seens as inappropriate as people may connect the wrong things to it therefore it is kept away from the general public.... so it is safer to just change the fan cable connection around when it is needed.

basically just swap the connected ground to 5v so that you have a 5v and 12v connection to the fan motor therefore giving you a potential difference of 7v, of course, you can buy tools to remove the pins properly.. or you can do it the cheap way and use a screwdriver to press the barbs in....

[Biscuit]

hmmm, would certainly be possible to just produce a little convertor to do it quickly..

so you just have a short male-female molex cable with the pins re-arranged that you just connect up (for some unknown reason i have a little molex cable that i just keep dismantling, on my desk )... but i suppose it could be seens as inappropriate as people may connect the wrong things to it therefore it is kept away from the general public.... so it is safer to just change the fan cable connection around when it is needed.

basically just swap the connected ground to 5v so that you have a 5v and 12v connection to the fan motor therefore giving you a potential difference of 7v, of course, you can buy tools to remove the pins properly.. or you can do it the cheap way and use a screwdriver to press the barbs in....

This technically works however i read over on SPC that it can damage your power supply.

[TAKTAK]

This technically works however i read over on SPC that it can damage your power supply.

cheap PSU's possibly... decent PSU's not...

a decent PSU just won't run if it has too much current going back to it down the 5v line wheras a cruddy one will just keep going

but practically everyone that has heard of/wants to volt mod fans has a decent PSU (or they should get one)

the whole 'it'll damage your PSU if you do this' is highly overrated TBH...

but... if you really were averse to it you could just use a simple potential divider between 12v and 0v to get your required voltage, obv it's a little more technical but it would work and there would be no possibility of damage.

edit: BALLS, i'd written a better edit but colleges 'authorisation' deleted it so in short:

you would use: Vout = (Ra/Rt) x Vin

so for example to get 7v

7 = (Ra/Rt) x 12

7 = (Ra/100k) x 12

Ra = (7/12) x 100k

Ra = 58333.3

so pick an appropriate E24 series resistor:

so 60k

so:

Vout = (Ra/Rt) x Vin

Vout = (60k/100k) x 12

Vout = 7.2v

[Biscuit]

I get enough of that stuff in my systems integration lessons dont bring it here aswell

i just make sure the fans are quiet when i buy them

[Nick]

cheap PSU's possibly... decent PSU's not...

a decent PSU just won't run if it has too much current going back to it down the 5v line wheras a cruddy one will just keep going

but practically everyone that has heard of/wants to volt mod fans has a decent PSU (or they should get one)

the whole 'it'll damage your PSU if you do this' is highly overrated TBH...

but... if you really were averse to it you could just use a simple potential divider between 12v and 0v to get your required voltage, obv it's a little more technical but it would work and there would be no possibility of damage.

edit: BALLS, i'd written a better edit but colleges 'authorisation' deleted it so in short:

you would use: Vout = (Ra/Rt) x Vin

so for example to get 7v

7 = (Ra/Rt) x 12

7 = (Ra/100k) x 12

Ra = (7/12) x 100k

Ra = 58333.3

so pick an appropriate E24 series resistor:

so 60k

so:

Vout = (Ra/Rt) x Vin

Vout = (60k/100k) x 12

Vout = 7.2v

I agree... sorry, what was that you said?

[TAKTAK]

I agree... sorry, what was that you said?

lool, i've just realised how ridiculous that way is... if you were going to go about it my way you might as well just bung a resistor in and keep it simple

basically tis just a standard potential divider, i.e. it can be used to get a reference voltage

Ra is the resistance that you are taking the voltage across (Racross)

Rt is the total resistance i.e. R1 + R2 (Rtotal)

wiki image:



in this image the R1 and R2 are labelled Z1 and Z2 but it shows you what i'm blabbering about , which is now irrelevant now that i've thought about it

so in that image, the voltage across Z2 would be:

Vout = {Z2/(Z1 + Z2)} x Vin

[Biscuit]

z = impedence which is the total resisting force of a wave or electrical signal (resistance capacitance and inductance) - well at least i remember something