Continue to Site

### Welcome to our site!

#### Arnold9801

##### New Member
I'm not equipped with much electronic info, so was asking if anyone could advise me on the wiring of my new 120mm 12v fan (as below) to an AC power supply?

I'm a little wearie regarding the identity of the three thin cables as can be seen and which two do I use to connect to the adaptors wires?

Arnold9801

#### Attachments

• 20221207_202332.jpg
884 KB · Views: 31
• 20221207_202228.jpg
5.8 MB · Views: 34

#### rjenkinsgb

##### Well-Known Member
If its a standard PC fan pinout, the right-hand pin should be 0V and the centre pin positive power.

You need to check the labels on the fan for the correct voltage; often 12V but 5V is possible.
See the diagram in the page here:

#### BR-549

##### Member
Is it a DC fan? AC power?

#### Arnold9801

##### New Member
If its a standard PC fan pinout, the right-hand pin should be 0V and the centre pin positive power.

You need to check the labels on the fan for the correct voltage; often 12V but 5V is possible.
See the diagram in the page here:
Ideally I want to connect it to the below adaptor. But which wire from the adaptor connects with those from the fan?

#### Attachments

• Screenshot_20221207-210242_Samsung Internet.jpg
146.3 KB · Views: 37

#### rjenkinsgb

##### Well-Known Member
Ideally I want to connect it to the below adaptor. But which wire from the adaptor connects with those from the fan?
That is possibly the worst type to use, as the polarity depends on which way around the cable and a tip are connected.

It may possibly be marked + and - on the sides of the adapter cable socket, next to the respective pin sockets?

Other than that, you need a multimeter to determine polarity.

Some universal adapters are also unregulated and the voltage with a small load may be rather higher than the switch setting indicates.

#### BR-549

##### Member
Alrighty then, as rjenkinsgb's link shows, Pos to red and neg to black. It will run at constant speed without a controller.

#### BR-549

##### Member
I didn't see the last 2 posts. Yes, you will need to determine the polarity of the supply. You have a meter, right? Some of those units are nasty pieces of work. Keep track of it's temp....power supply, not fan....when first using it. Your touch will do.

#### Arnold9801

##### New Member
I didn't see the last 2 posts. Yes, you will need to determine the polarity of the supply. You have a meter, right? Some of those units are nasty pieces of work. Keep track of it's temp....power supply, not fan....when first using it. Your touch will do.
The fan manual shows the wires as attached. Which two do I connect to the wires of thd adaptor?

#### Attachments

• Screenshot_20221207-212326_Samsung Internet.jpg
330 KB · Views: 35

#### rjenkinsgb

##### Well-Known Member
Unless the adapter itself is specifically labelled with polarity, there is no way of knowing - other than using a multimeter.

A fixed 12V adapter with a fixed connector and clearly indicated polarity would be far simpler, and probably cheaper.

#### BR-549

##### Member
First.....you have to determine which wire from adapter is positive and which wire is negative. Can you do that?

If you can, get some tape and label the wires, ok?

Your picture is fuzzy and my eyes are old. It appears the pin 1 is ground or negative, and pin 2 is the positive.

#### Arnold9801

##### New Member
 [QUOTE="rjenkinsgb, post: 1430830, member: 273344"] Unless the adapter itself is specifically labelled with polarity, there is no way of knowing - other than using a multimeter. A fixed 12V adapter with a fixed connector and clearly indicated polarity would be far simpler, and probably cheaper. [/QUOTE] Can you give me an example?

#### BR-549

##### Member
Every man needs a meter. It's a man thing. HUH HUH. I recommend the VICI VC99 multimeter. It's cheap. It has many functions. And it preforms well above the advertised specs.

#### BR-549

##### Member
And of course, one could pick up one those \$4.99 little yellow meters from Harbor Freight, for your purpose. That might be better for a new student. People usually burn up their first meter.

#### rjenkinsgb

##### Well-Known Member
Can you give me an example?
A generic 12V adapter with a permanently attached connector, and the polarity indicated on the label.

eg. Anything like these, with the appropriate wall plug type for your country;

Both of those have the outer of the plug as negative and the inner as positive, which is the commonest polarity.

#### Arnold9801

##### New Member
A generic 12V adapter with a permanently attached connector, and the polarity indicated on the label.

eg. Anything like these, with the appropriate wall plug type for your country;

Both of those have the outer of the plug as negative and the inner as positive, which is the commonest polarity.
Many Thanks.

Replies
7
Views
1K
Replies
2
Views
694
Replies
48
Views
13K
Replies
9
Views
5K
Replies
24
Views
2K