DC Power Jack help. (I'm a noob)

I have a small electronic project to make several 12v pc fans run off a power supply other than PSU.

I currently have a 12v 4amp cctv power supply with a 5.5 x 2.5 Coaxial plug end. I want to use a Coaxial DC power jack to attach 4-pin molex connect to and so that to power my fans. I would also like to be able to leave the unit plugged in and attach some form of switch to the circuit so that when I power on my electronics the switch is activated and the fans start to run.

I bought a DC power jack to day that says "Coaxial DC Power Jack with Switch"

Below are the picture of the DC Power Jack and the back of the packaging. I don't understand which connection does what on the Jack. My plan is to use a standard test light set up and test which connection controls the center pin and other parts so that I get my polarity correct. What I don't understand is the switch part??? and how I control that switch.

Can I use a power point on the electronic circuit I what to connect this to so that when that unit is turned on it will activate the switch and turn the fans on?

Thanks for your help in advance. Any reference sources would also be great I have searched the net for a couple of hours before posting in this forum looking for explanations of the power jack and how this switch work with no luck. I'm probably looking in the wrong directions or not the correct terminology.

Scoopburt

**broken link removed**
**broken link removed**

The switch is to turn off something when you plug into the socket.

These are usually used on stuff that may be powered from batteries or mains. There is some sort of external transformer, reducing the mains to a similar voltage to the batteries, and the power comes to a coaxial plug.

One battery connection, usually the negative, is connected to the switch. When nothing is plugged in the switch is closed and the battery powers the unit.

When the transformer is plugged in, the switch opens and the transformer powers the unit, but does not charge the non-rechargeable batteries.

Diver300 said:

One battery connection, usually the negative, is connected to the switch. When nothing is plugged in the switch is closed and the battery powers the unit.

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He's referring to the NC switch shown on your device.