Reversing Fans.

[Ghost]

I know some fans on start up start spinning backwards for a few seconds before going forwards. (I think its on MSI GPUs)

Does anyone know of a system that could make fans do this, like an adapter? It would be very good at getting rid of dust lodged in places.

[KingLinkTiger]

I did a quick search and it seems that in most cases it would be impossible to use an adapter. In most circumstances you could just switch the polarity to the fan (ie switch the black and red) but many fans have "stuff" built in to prevent this, protecting the fan motor from possible damage. So, the best bet would be buy these special fans or adjust your internal case pressure to reduce dust.

[Ghost]

As far as I am >>aware<< you can't actually buy fans/adapters like this, they come in pre-built things like PSUs and GPUs.

The only good technology carried on from these things to case fans is that some mobos keep then fans powered on for a while after your system is off to allow it to cool down.

I may make this a modding project of mine to try and create a system that can reverse a fan for a few seconds at the start.

[KingLinkTiger]

As far as I am >>aware<< you can't actually buy fans/adapters like this' date=' they come in pre-built things like PSUs and GPUs. The only good technology carried on from these things to case fans is that some mobos keep then fans powered on for a while after your system is off to allow it to cool down. I may make this a modding project of mine to try and create a system that can reverse a fan for a few seconds at the start. [/quote']

Haven't heard of a fan mod before. I'd be interested to hear how that turns out.

[Art Vandelay]

Here's something to try, attach the fan connector to a 3 pin to molex converter that you don't mind destroying. Pull the molex pins and hold them against the terminals of a 9 volt battery. Only when you hook up the black wire to the negative terminal and the red wire to the positive terminal will the fan actually do anything.

They probably just put a diode in the circuitry to prevent you from hooking it up backwards, so if you remove it, it should work. This could be completely inaccurate, though.

If it will only work on one polarity, the manufacturer did if for a reason.

[Ghost]

Here's something to try' date=' attach the fan connector to a 3 pin to molex converter that you don't mind destroying. Pull the molex pins and hold them against the terminals of a 9 volt battery. Only when you hook up the black wire to the negative terminal and the red wire to the positive terminal will the fan actually do anything. They probably just put a diode in the circuitry to prevent you from hooking it up backwards, so if you remove it, it should work. This could be completely inaccurate, though. If it will only work on one polarity, the manufacturer did if for a reason.[/quote']

Damn, I'll have to try that later.

[MoeBrowne]

Normal fans are brush-less meaning an IC is required to deal with the coil switching (also RPM sensing) so unless 'reverse' is an in built function of the control circuitry there is no way to reverse the spin.

[Fordox]

reveersing the spin is imo not practical. you wont suck dust out of your case when its already settled. let alone with some fans which won't move a lot of air (pc fans aren't really powerfull).

it wont work... maybe on your cpu block, but you are blowing that into the case. if you can aim it at an exhoust, it might work (for a bit). but thats it.

the anti dust functions from msi are also a bit overrated. and that heatsink is a lot thinner, so dust can barely settle in.

[Konn]

I don't think it would make much of difference to be honest as it's not easy to suck dust out of a case. You do also have fan filters after all, maybe.

[Ghost]

I don't think it would make much of difference to be honest as it's not easy to suck dust out of a case. You do also have fan filters after all' date=' maybe.[/quote']

The problem isn't quantity of dust that much. Its the very very tiny powder dust that does manage to get through. It just makes the whole system look coated with a gray powder if you forget to look after it for a few weeks.

[Wauthar]

I think the thing is: when you manage to get the fans to spin in reverse, it wouldn't do much. You see, the fans of a GPU spin faster than a normal casefan, so...