Connecting processor fan to the mains

JonathanAnon

Hi guys,

I have a processor fan that I want to use for another purpose.. Obviously I wont have the PC to power it, so I want to plug it straight in to the mains.. The fan is 12v 0.15A.. I read on-line that you can get a variable voltage/current and simply hook up the wires..

Just wondering is there an easier way of doing this.. ?

thanks,
J

Redisle

You could hook it up to a standard 12V wallwart (Plug in adaptor). Easiest way to connect it up would be to cut the wires on both then solder the two together. The two wires you need to connect from the fan are the Black and Red. (some fans have 3 or 4 wires).

JonathanAnon

Yeah I was gonna get one of those.. I had a bit of trouble finding one with the exact 12v 150ma setting.. I was hoping that maybe there was something that would connect that little three pin connector straight to the 240v mains.. Gonna have a look for an adapter today..

Chet T16

Once the adapter is 12v and equal to or over 150mA it'll be fine. Thats only the maximum rating, the fan will only draw as much as it needs

JonathanAnon

just wondering lads, since this is just something experimental.. I might just try a 12v battery.. the rectangular one.. Will the battery similarly draw whatever current it needs from the battery?

ressem

Chet T16 wrote: »

Once the adapter is 12v and equal to or over 150mA it'll be fine. Thats only the maximum rating, the fan will only draw as much as it needs

That's not correct. If the adapter is rated for a higher current than the device then those wall warts will increase the voltage, and send too much power through the fan.

Edit:
If it's a switching power supply then the voltage should be constant, if a transforming power supply, it might be at 150-160% voltage with a low load.

For something simple like a fan, a battery would be ok. A 9V battery would likely work, running a basic CPU fan at a slower speed.

JonathanAnon

Hi guys, appreciate the advice so far.. making a bit of progress...



I've hooked up the red wire of the fan to the positive on 9v battery and the black to the negative and the fan kicks on.. This will certainly work for me for testing (to see if it will actually work as a proper solution for what I'm trying)..

wil

JonathanAnon wrote: »

Yeah I was gonna get one of those.. I had a bit of trouble finding one with the exact 12v 150ma setting.. I was hoping that maybe there was something that would connect that little three pin connector straight to the 240v mains.. Gonna have a look for an adapter today..

I feel like I am stating the blindingly obvious here but as nobody else has said anything

- PLEASE DO NOT CONNECT ANYTHING LIKE THIS STRAIGHT TO THE MAINS.:eek:

You'd be surprised what people do, but I'm not.
Only connect properly earthed or shielded mains equipment to the mains.

zom

JonathanAnon wrote: »

Yeah I was gonna get one of those.. I had a bit of trouble finding one with the exact 12v 150ma setting.. I was hoping that maybe there was something that would connect that little three pin connector straight to the 240v mains.. Gonna have a look for an adapter today..

@JonathanAnon - I have some spare old but still working 12v adapters, can send you if you pay post fees (or you can collect if Dublin Centre).
As will already mentioned DON'T PLAY WITH MAINS, IT CAN KILL YOU.

JonathanAnon

Yeah dont worry lads, I know a bit about these things.. When I say "connect to the mains" I really mean that I am looking for some facilitating adapter or transformer... I just thought that there may be an adapter specifically for connecting such a (commonly used) processor fan to the mains.. but apparently there is not...

Here's where I am now..



I got the connection for the 9V battery, and a switch to put in between the battery and the fan.. Works fine..

wil

JonathanAnon wrote: »

Yeah dont worry lads, I know a bit about these things.. When I say "connect to the mains" I really mean that I am looking for some facilitating adapter or transformer... I just thought that there may be an adapter specifically for connecting such a (commonly used) processor fan to the mains.. but apparently there is not...

Here's where I am now..

I got the connection for the 9V battery, and a switch to put in between the battery and the fan.. Works fine..

Thats what worries me most

There is. It is called a PC power supply. Power goes to board, fan to board allowing switching or variable speed, or alternatively usually with a 4 pin molex, power direct to fan.
If you need for a simple cooling project you need a variable or 12 v DC power supply, no real need for connectors if you strip the wires and connect direct to 12v, NOT mains.

JonathanAnon

I appreciate what you're saying... but I used to build PCs every day in a previous job.. so I think it's legitimate that I say that I know a bit about PCs.. But I obviously dont want to bring a PC power supply around with me..

The battery is a fine solution for the moment, but hooking up to the mains is the long term solution (once I'm happy that the processor fan will suffice)... I've looked up adapters that are 12v / 150ma / DC online, but I cannot locate one locally.. but I'm gonna keep looking..

Chet T16

http://www.argos.ie/static/Product/partNumber/9829701/Trail/searchtext%3EVOLTAGE+ADAPTER.htm

That will work perfectly, bit expensive mind

JonathanAnon

Chet T16 wrote: »

http://www.argos.ie/static/Product/partNumber/9829701/Trail/searchtext%3EVOLTAGE+ADAPTER.htm That will work perfectly, bit expensive mind

Yeah that looks like the job alright.. It is 1200mA though, and my device is 150mA.. Will the device just draw the current that it requires (and no more) as was mentioned above?

bonzodog2

The fan will only draw its rated current, even if used on a supply with greater capacity. Try looking in a 2euro shop perhaps, or maybe you know someone with an old router or modem, they often have 12V supplies, typically 1000mA.

JonathanAnon

The 12 euro one will be fine... I just need to test it out a bit with the battery.. I've a bit of metalwork and tapping to do to fit in on the stand I want to use it on... I post a pic of the finished product.. thanks..