# Maplin Cooling Fan for SOG



## Auldgadgey (Jan 25, 2009)

I'm trying a Maplin PC cooling fan 12v 38 x 38 x 38mm in a SOG system.
It works fine until it "sticks" the fan seems to have a position where instead of rotating it "quivers"
There are three wires to the fan red, black and yellow.
I suspect that the yellow wire is a control and I'm not using it, should I?
Any help appreciated.

Tony


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## erneboy (Feb 8, 2007)

Tony, sorry I can't help with your wiring question. But having had to buy a new SOG fan last year at £?? I would like to know how you get on.

I considered a computer fan but couldn't think of an easy way to box it in. Please let us know your solution perhaps with a few photographs, Alan.


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## Pat-H (Oct 30, 2009)

Computer fans have 3 wires and the yellow one is normally a counter output. Thi is so the "PC" can measure the rotation speed.
So it's an output not an input. The speed is controlled by just changing the input voltage to red and black.
If it sticks then it's most likely faulty. They are brushless so have magnets and sensors inside and as the fan and magnets rotate the sensors trun on and off the pulling coils. Sounds liek one coil or sensor is faulty.


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## Auldgadgey (Jan 25, 2009)

Pat-H
I have been wondering about a faulty fan, it used to be quite noisy when I first installed it now it is very quiet. It happened mid use one day, at first I thought it had packed in altogther but on inspection it looked OK.
Might there be a problem with the amperage of the van 12v as against the usual amperage in a PC?
I can't take it back for refund as I trimmed the square off one end to fit into the door aperture


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## pippin (Nov 15, 2007)

Nowt to do with "amperage".

Your computer shoves out 12V DC for the fan.

Your MH might shove out up to 14V but is unlikely to damage the fan.

I use two computer fans to cool the back of the fridge.

I use two more in switchable series/parallel in each of the rooflights.
The pair over the bed suck fresh air into the MH, the ones in the lounge area blow air out.

Never had a moments problem with any of them - except noisy bearings.

When (if) my SOG fan packs in I will save a hefty amount of money by replacing it with a computer fan.


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## Auldgadgey (Jan 25, 2009)

Ernieboy
If all goes well there should be a couple of attachments to this mail showing my ersatz SOG.


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## Auldgadgey (Jan 25, 2009)

Erneboy
I was stuck with the "how to box it in" problem until I saw that Maplin sell a 38 x 38 x 38mm 12v cooling fan. The door on my toilet access is 38mm thick so the fan fits into it. I used a undersize holesaw to make the initial aperture and opened it up with a souter until I had a neat fit.
The SOG fan has a right angle bend for the pipe to fit onto and I can see why, as this would keep the pipe much neater against the wall of the compartment.

I sealed all round with silicon to stop back drafts.


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## Pat-H (Oct 30, 2009)

Auldgadgey said:


> Pat-H
> I have been wondering about a faulty fan, it used to be quite noisy when I first installed it now it is very quiet. It happened mid use one day, at first I thought it had packed in altogther but on inspection it looked OK.
> Might there be a problem with the amperage of the van 12v as against the usual amperage in a PC?
> I can't take it back for refund as I trimmed the square off one end to fit into the door aperture


You can normally strip them down quite easily. They normally have a rubber bung under the sticky label and inside that will be a clip that lets you remove the fan.
But as it's all solid state there's not much you can do excpet look for dry joints or muck in the way.
One option would be to buy a second replacement fan and use the internal parts to "fix" your one. If that works make back up the new one and return it for a refund...


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## Auldgadgey (Jan 25, 2009)

Pat-H
Ooohhh thats sneaky, but I like your thinking :lol:


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