Make-shift Fan

[macdad-]

Calum im replying back to the post about overclocking. The make shift fan i made using the old CPU fan from my other computer and powering it with 2 9Vs was able to drop my HD temp by 5 degrees  and kept it steady there. So just to post it there.

[homer]

your powering a fan with 2 9v batteries?

[Dias de verano]

in series or in parallel?

[Calum]

Glad to hear it's working out for you.

[macdad-]

in series but i think i would do better with a AC wall adaptor. The batteries died after 7hours of keeping the computer cool

[Dias de verano]

in series but i think i would do better with a AC wall adaptor. The batteries died after 7hours of keeping the computer cool

The usual way is to take DC off a disk drive power connection with a Molex splitter

yellow=+5v, black & black=ground, red = +12v

[homer]

in series but i think i would do better with a AC wall adaptor. The batteries died after 7hours of keeping the computer cool

an added note, most computer fans are 12v. by giving it 18v you are decreasing the life expectancy of that fan.

[Dias de verano]

an added note, most computer fans are 12v. by giving it 18v you are decreasing the life expectancy of that fan.

black=ground, red = +12v

[homer]

your powering a fan with 2 9v batteries?

in series or in parallel?

in series

9+9=18v its really not that hard...

[Dias de verano]

your powering a fan with 2 9v batteries?

in series or in parallel?

in series

9+9=18v its really not that hard...

What isn't? [I do so hate being patronized!] I am not sure what point you are trying to make. Perhaps you could elucidate? At the time I asked, it was not clear whether he was connecting the batteries in series or parallel -- hence my question. You may not be aware that there are two ways of connecting two batteries (well two useful ones!) series: twice the volts, same number of mAh as one battery, or (equally plausibly at that stage of the thread, and actually more sensible with a 12v fan) parallel: same voltage as 1 battery, twice the mAh. (mAh=milliamp hours).

So what is your point?

[macdad-]

in series but i think i would do better with a AC wall adaptor. The batteries died after 7hours of keeping the computer cool

an added note, most computer fans are 12v. by giving it 18v you are decreasing the life expectancy of that fan.

actually there is a nomial voltage for all fans they can run between 50% and 150% of there specified voltage. so 18V isnt killing the fan. but at 30V will make the fan overheat and die. 12 x 150% = 18 + 12 = 30V

[homer]

they can run between 50% and 150% of there specified voltage.

where did you get these numbers?

[street1 (RIP)]

they can run between 50% and 150% of there specified voltage.

where did you get these numbers?

 

[homer]

an added note, most computer fans are 12v. by giving it 18v you are decreasing the life expectancy of that fan.

black=ground, red = +12v

explain what you meant by this dias.

[Dias de verano]

an added note, most computer fans are 12v. by giving it 18v you are decreasing the life expectancy of that fan.

black=ground, red = +12v

explain what you meant by this dias.

I was reiterating that he doesn't need a wall wart, he can get 12v DC from a Molex (disc drive) power connector.

The colours of the wires denote the polarity & voltage.

Yellow, + 5v, black, ground (2 of these), red, + 12v

Rather than mess about I would use one of these, cost in Britain 2 UK pounds (about 4 US dollars)



Or one of these cost 5.99 UK pounds, about 12 $USD - this one has 12v (black/red) & 5v (black/yellow) fan connectors to give choice of speeds.



You can spend more and get ones that have a little module with a speed control knob and I saw one that a case modder would like that had red & blue LEDs and silver speed control knobs

But most motherboards have multiple fan headers on them, that fans plug into directly & I wonder why macdad didn't use one of those. Maybe there wasn't a spare one available?