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Ventilation

I just bought a tank and it's very hot (36 Celsius is too hot for my dews !) I want to install a cpu fan, but I am not sure how to do it.

I know that cpu fan operates with dc current, and it uses a molex plug. I don't want to get a psu just to use a muffin fan lol. I searched around the forum and i believe that I need some sort of ac/dc adapter from radioshack .. but I don't know which one to buy and how to connect the molex to the adapter. Can somebody please give me a step by step instruction ? Sorry to bother you guys again ..

Oh and I found this adapter http://hififorless.com/showPro....7d23959 I dunno if this one works or not.

KayWhy.
 
You need to get an adapter that supports the same voltage and similar amperage to the fan.

Most 80mm computer fans use 12V, at varying amperages (rated in milliamps, mA).  Get an adapter that has the same voltage, and a higher amperage.  For example, if you have a fan that uses 12V 100mA, you would want to get an adapter that supports at least 12V 200mA.  Not all ratings are perfectly accurate, so having a little extra keeps it from overloading the adapter.

Power rating can usually be found on the fan.  1A=1000mA.
fan.jpg


You can find really cheap adapters at thrift stores (this is where I got mine), usually $1 each, and they will usually tell you the V, A, and wiring configuration.  However, these obviously have no warranty or safety instructions, so you may want to buy an adapter at RadioShack if you don't feel comfortable with this option.

Tools Required:
tools.jpg


1. Fan
2. AC Adapter with ratings appropriate for fan specs
3. Wire crimper/stripper
4. Insulated Butt Connectors (at least, this is what RadioShack calls them) that are appropriate size for the wire; the red ones should work with most fan wires.

To connect the fan, follow these steps:

1.  Cut the molex connector off of the fan.  You should have a red and black wire.  If the fan has 3 wires, ignore the yellow wire, this is for fan speed detection.

2.  Strip the wires so that they are the appropriate size to fit inside the butt connector.

2.  Use one of the butt connectors to connect the positive wire of the fan to the positive wire of the adapter.  If you don't know which is positive and which is negative, you can test by trying both combinations before using the connectors.  The fan should only spin when the wires are connected properly.  Be careful not to cross the positive and negative wires, as this will cause a short.

3.  Crimp the butt connector on to the two wires.  Your wire crimper may be color coded to show you which hole to use for the crimping.  Be sure that the wire is crimped firmly on both sides.

Should look something like this after crimping:
connector.jpg


4.  Repeat steps 2 and 3 for the negative wire.

Remember, always be careful and test the setup thoroughly.  Make sure the power adapter is not getting unnaturally hot (they are warm under normal use).

Hope this helps.

-Ben
 
Hey Ben,

Your step-in-step instruction really helped.  I think this should be a sticky post
smile.gif
. When you crimp the butt connector on to the two wires do you first twist the wires together first ?


If I buy this adaptor (below), you see the two holes on the left of the screen, I can just cut out the molex and wire the positive and negative wires into those two holes, am I correct ?

AD-500.jpg
 
Nice post. Just wanted to note that if you reverse the wires the fan will spin but it will spin in reverse. So just check to make sure the fan is spinning in the correct direction before crimping down the connectors.

I guess you could stick the two bare wires from the fan into the holes Kaywhy although you may not get a good connection. You may also have some bare wire sticking out which is a potential for a short.

Tony
 
KayWhy, you don't need to twist the wires together before placing into the butt connector; in fact, doing so is impossible.  I first cut the molex connector off the fan wires, and then cut the plug off the end of the adapter. You need to place the lead from the adapter wire into one end of the connector, and the lead from the fan wire into the other end of the connector.  Then you crimp it to hold the wires in.  Edit:  I added some text to the picture of the connector, refresh the page to see it.

If you want to use the adapter you posted, without cutting the end off (since your adapter is more expensive), I would recommend getting a female plug to wire onto the fan wires.  This way you will get a firmer connection, and not risk a short, as Tony mentioned.  This will also allow you to disconnect the adapter easily if you ever need to do so.

Tony, thanks.  My fans simply don't do anything when wired backwards, so I guess it depends on the fan.

-Ben
 
Hey Ben, I bought all my stuff and the fan is working smoothly. Thank you sooo much for your help !
 
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