fans conections.....are safe??????????

stv · Post by **stv** » Tue Nov 28, 2006 8:44 pm

i have 3 fans conected to same molex:
- one have the 7 volt trick
- two at 5 volt

the system runs fine... but i want to be sure
one never knows

disphenoidal · Post by **disphenoidal** » Tue Nov 28, 2006 10:44 pm

That is indeed safe.

Also, nice drawing. One small comment, though. You have your ground rails labeled as Ground 5V and Ground 12V? There's no need to do that, both ground wires are the same, and are both grounds for both the 5V and 12V lines.

Bluefront · Post by **Bluefront** » Wed Nov 29, 2006 3:07 am

Safe? IMHO.....the 7v mod is electrically questionable. I prefer to lower voltage with a resistor or a cheap fan controller.

Molex connectors.....seem to vary quite a bit in quality. I've had wires with poor electrical connection, and wires that pulled loose. I'd recommend taping the wires and connectors after your project is finalized, for maximum safety. The safest connection would eliminate all these molex connectors, and solder the whole wire harness into one piece. I know....overkill. But you asked for safety.

When trouble-shooting electrical problems, which I also do for a living, the very first place to check is any quick-disconnect joint........

stv · Post by **stv** » Wed Nov 29, 2006 8:39 am

thanks for the replies

Bluefront you have a good point
a cheap fan controler can do a better work...
but i do not want spent more money...

my PSU is a seasonic s12 380

Sunbeam Rheobus can do the the task....

any advice about cheap fan controlers??????????????'

Centie · Post by **Centie** » Wed Nov 29, 2006 12:18 pm

If its just for the one fan I don't think you can beat a zalman fanmate for cheapnes (Â£3 here). For more fans the akasa fan controll jnr. (sold under different names around the world I think) works well enough down to 6V for 3 fans, for around Â£8 (or Â£4 of ebay

). Of course, all depends on where you are and whats available.

Have you thought of using speedfan and motherboard fan headers? If that works for you would be cheapest solution!

disphenoidal · Post by **disphenoidal** » Wed Nov 29, 2006 12:38 pm

Bluefront wrote:Safe? IMHO.....the 7v mod is electrically questionable. I prefer to lower voltage with a resistor or a cheap fan controller.

The 7V mod is only questionable when a lot of current is being sunk into the 5V line. Just one fan is unlikely to be a problem. And he has two other fans drawing current from the 5V line, which will cancel out any current being sunk by the 7V modded fan.

stv · Post by **stv** » Thu Nov 30, 2006 10:15 am

thanks disphenoidal
you are right

i'm afraid when i read this

Caution! There are people, who will say "You can't feed current back into your power-supply" and they are right!

If you plug something between the 12V and 5V lead, you have to be absolutely sure, that no current is fed back into the PSU. Which means, that you need to have other loads on that 5V lead, which suck out more current than you feed to that lead from the 12V lead.

but with 2 fans in the 5v line
a 80mm zalman and
a 120mm tt
i will be fine

but something bother me.... the cable mess
and how i said before

Bluefront you have a good point
a cheap fan controler can do a better work...

a zalman fanmate only control one fan....

spent $15 +shippnig for a cheap descent fan controler

centi do you have some links for de Akasa controler?????

Centie · Post by **Centie** » Thu Nov 30, 2006 1:22 pm

From the manufacturer..

http://www.akasa.co.uk/akasa_english/sp ... c_06bk.htm

But it's just a rebranded version of this one review here..

http://www.silentpcreview.com/article133-page1.html

You might have some luck searching by the model number (ATN-TP-02E), it's readily available in the UK but I don't know about anywhere else.

stv · Post by **stv** » Thu Nov 30, 2006 2:11 pm

thanks centie

i am fron Costa Rica

a little contry in Central America

i don't think i cant find here....
but maybe i can find something like that