@sHawTY
Hi bro.. i was adding cooling fan like this HERE
I know its wrong.. will it damage my PSU and Hardware?? Can tell me pls.. Thanks

This post has been edited by yehlai: Oct 22 2006, 12:14 AM

Its not wrong, just have to make sure you don't accidentally short circuit something..for safety pull the plug when you're wiring it and double check the connections before connecting the main power cable back. Welcome to making full use of your PSU. Just as a guide, connect the

:sHawTY
YESSSS, got the PWM working! Ran a few fans on it, works like a charm. And yes, fans do stop if set too low..so wierd to see a fan vibrating..not enough power to spin properly.. As a plus point, if I set the 555 signal generator's frequency low enough (audio range) the fan will emit a squealing sound when too slow/stopped..nice fan failure warning.

Of course I didn't have enough..since I had a 33A MOSFET (shop didn't have the 3-5A I was looking for, so I just randomly picked another one in the same product series-didn't have datasheets to refer to at the time), means it can handle the current draw of the 130W peltier I just bought from ff7yta..put it in between my pipe101 and a leftover Athlon heatsink..and lo and behold..water soon started dripping from the Athlon HS (cold side) ..and all that still controllable by PWM..woot!

So still want one, sHawTY?

PS: Also rigged up PSU tester working (using 1A load on each line)..only that had to use a DMM to measure..must rig up a LED display soon. Wonder if people would be interested to buy stuff like this? Planning to build a PSU full loader (>500W) to play around with. Also thinking of trying out some of the high voltage experiments on RM Cybernetics..somebody call me crazy..

me tooo...

but i always pull the fan's wire in and out to connect and discconect it while pc power is on... im really noob..
will this make dmg to other hardware??

Thank you so much lohwenli.. i will follow ur advice always pull the plug when wiring it and double check the connections before connecting the main power cable back.

This post has been edited by yehlai: Oct 23 2006, 11:51 AM

Well, if your hands are damn steady and you don't short circuit anything then you can even with power on..but I don't recommend it..blew a circuit once when I accidentally crossed a 12V line to ground (VGA fan). Lucky the PSU safety switch shut it off or else it would have blown up . Had to do some painstaking soldering on the blown AGP contact..TRUST me, this is not something you'll want to do ..imagine if it was something more expensive?

What I still consider somewhat safer (but still need steady hands, and only if you really need to do it)-is connect proper connectors (3-pin fan, molex) while the power is on. Any loose conductor in a PC is a potential problem, if you need to wire anything while the PC is on take EXTREME care not to cross any contacts except for those which you intend to (and make sure you know well what are you are doing).

About damaging other hardware, it won't happen unless you short something or overload the PSU (unlikely if you're dealing only with fans).

hehe thanks..
b4 tht i tot everything is safe and easy to handle.. becoz just a small smaal fan.. runing 12V DC also (i think its little). Haha proof tht i was wrong lolz

better just leave it.. dont play too much with it, as long as it can run then ok ledi...

This post has been edited by yehlai: Oct 23 2006, 08:49 PM

Or you could probably make a switch to turn the fan on and off as you like...

A switch is not a very hard thing to be done right?

Some extra guide to make you're fan run at a speed that is over the maximum speed you're fan is set to run on...



This guide is a courtesy of mADMAN...

Salute "Lelaki Gila"...

This post has been edited by sHawTY: Nov 13 2006, 09:45 PM

salute to me for wat??? salute to shah81 la....

he mentioned it before here...its just that i remembered what he said

I need to do some correction for you, there is NO -3.3v line, only a +3.3v line..


Might as well I give the full list

All possible fan voltages (connect lower voltage to black wire)
-Note that the negative voltage lines cannot handle much current, one high power fan is probably the most it can handle.

+12V & -12V =24V
+12V & -5V =17V
+12V & GND =12V (default)
+12V & 3.3V =8.7V
+12 & +5V=7v

+5V & -12V =17V
+5V & -5V =10V
+5V & GND =5V
+5V & 3.3V =1.7V

+3.3V & -12V =15.3V
+3.3V & -5V =8.3V
+3.3V & GND =3.3V

Any voltage above 12V, use at your own risk-fan will most likely spin quickly for a short while then go up in smoke equally fast. Also, if using anything other than the default voltage, RPM measurement might not work properly.

Voltage line identification
+12V -yellow
+5V -red
+3.3v -orange
Ground - black
-5V -white (not present in newer PSUs as no longer needed by current PCs)
-12v -blue

This post has been edited by lohwenli: Nov 15 2006, 01:56 AM

Owh, really?

Salute to shah81 then...

Hehe

Owh, thanks mate!!!

That sure help us alot in understanding it...

one thing i not so clear, how we estimate the fan speed after undervolting it at 7v or 5v... sry for noob question, kinda lack of knowledge bout this....

Use Speedfan or PC Wizard 2006.

Those softwares will show the speed of you're fan...

may i know where can i get this item?

i think moderno got em, pm him lor

Ask this guy:

tnghian
http://forum.lowyat.net/index.php?showuser=3961

i think change the transistor in the fan's electronis board....then the fan will spin very fast

And that will kill you're motherboard very fast...

Not to forget that'll kill the motherboard's manufacturing warranty...

I think its possible, planning on opening one of my half dead fans to try (probably in a month's time, super busy now). Based on what I understand on how DC brushless fans work they have an unusual ammount of electrical resistance for the circuitry involved. Lowering the resistance to increase the current will get the fan to spin faster. Real danger is that your fan will burn out-coils are designed to only handle up to a certain amount of current depending on the type of wire used and its heat dissipation capability (don't dream of putting a heatsink though). Unlikely that you'll fry the motherboard, most also the mobo will not be able to read the fan rpm-happens on my Abit IS-7, sometimes when the fan speed is too high it will just read zero.

Reason why fan speed might not read correctly when using other wires than ground for the black fan wire-fans produce a signal switching between a high voltage and a low voltage for each fan revolution, typically the low voltage will correspond to the voltage connected to the black wire. Once something other than ground is connected, the monitoring chip might not be able to read the low voltage as its not low enough, so the rpm count will remail zero.