Sharing fans between 2 machines.

[3 of 7]

Originally Posted by Lima

I can also now understand how it would be a good idea to use a dedicated PSU to run a few fans like these.

No psu for these, they plug into the wall ( Thus the 115-120v ratings)

[Lima]

Originally Posted by MpG

If you want to do this directly off the motherboard(s), you'll need some variation of a triple-pole-double-throw (TPDT) switch, which will switch all three connections at once. I'm honestly not sure what would happen if the speed sensor sends signals to the inactive motherboard - the signal strength is much weaker than the fan's main power, but there is still some voltage and current being produced, and I'm not entirely certain of how the inactive circuitry would handle it. So if you want to run off motherboards, and you want any rpm monitoring, you'll need to handle it somehow. I stand to be corrected on this part, but I don't believe plugging the speed sensor into both boards is a good idea.

Ah yes, I got a little carried away there for a sec. Like the DPDT switch but TPDT cuz of the new sensor connection. Gotcha. You are right though, no need to plug my fan controler into both motherboards. The sensors included with the controler are there to display the temps around the fan area or where ever I choose to place them..

And on to the hunt.

This -> is Addison Electronics Relay/Contactor/Solenoid page, a store that is not too far away that I would be able to visit and buy a relay. Can you guys take a look and point out which relay I should be looking for?

There is also Maddison. Here -> is a link to pages 253-264 of their online PDF (Look for page 256 in particular), that's where their relay selection is.

Originally Posted by 3 of 7

No psu for these, they plug into the wall ( Thus the 115-120v ratings)

Wow, it didn't even occur to me that it might :).

[MpG]

THIS would probably handle things alright. It will handle up to four connections, will switch with 12VDC, and will handle 5A/contact. Just be careful when connecting the wires - it'll be a little crowded, so make sure there's no exposed metal wires that could short things out.

[Lima]

Originally Posted by MpG

THIS would probably handle things alright. It will handle up to four connections, will switch with 12VDC, and will handle 5A/contact. Just be careful when connecting the wires - it'll be a little crowded, so make sure there's no exposed metal wires that could short things out.

It's asking me to sing in. I am not signed up there.

*Edit. Never mind. It seems to work now .

Thanks MpG!

[Lima]

So I will have to solder the wires on?

[MpG]

It's hard to tell from the picture, but you might be able to use regular female spade connectors (pretty easy to find at your average C.Tire auto section and other places) and slide them onto the terminals. Soldering is nice, but permanent, and if you're not used to that sort of thing, it's easy to accidentally melt the plastic housing that holds the terminals steady.

[Lima]

You know? While we're on the subject, let's dissect this little guy.

Originally Posted by MpG

It will handle up to four connections

I assume this means that I can connect upto four devices.

Originally Posted by MpG

will switch with 12VDC

That the twelve volts running through a PSU's rail will signal the relay and it will switch to the availble power source.

Originally Posted by MpG

and will handle 5A/contact.

And that this would maybe suggest that it can handle up to 5A per connection.

So, how did I do?

[MpG]

Yup, that's the gist of it.

Although now that I think of it, if there's a two-pole version of that relay, you'd be fine with that. I was still thinking rpm wire-->motherboards when I picked that one out.

[Lima]

Well, since the spades would touch, I bought a stand for it.

I drew the diagram that is on the relay so you guys can maybe help me figure it out.