What connection do I need . . . ?

seoirserob

Hi all. I'm a little confused. I have a 7 inch monitor for a car head rest, which comes with cables to connect to a 12V battery. How would I go about connecting this device to a mains power supply? image attached.

Gadgetman496

Assuming you are in Ireland? you would need a step down transformer 230VAC to 12VDC but it would be a lot of hassle. Why do you want to do this?

seoirserob

Thanks for the reply . . .

I have a small 7 inch monitor that I would like to use in my workshop as the monitor for a media drive (mostly for music) . . . space is limited. The monitor has only one electrical cable coming out of it, and no input or output sockets, this hooks up to the cables in the image attached earlier. the battery power cables share the same connection as the coaxial video.

Yes I am in Ireland.

Any ideas? the monitor would be perfect where I need it to go, if I can find a way to switch it on, and connect it to the drive . . . using a battery will make it more hassle than it's worth I think, I just need to be able to plug it in. I had considered finding an old adapter for some other (12V) device and splicing the wires with the cables on the monitor . . .

Inspector Gadget

You need a "wall wart" capable of delivering any voltage between 12 and 14 volts DC (symbol is a solid horizontal line over dashed horizontal line. If you see a wavy line instead - a symbol for a sine wave - on the output that's AC which you don't want).

However, you haven't stated the current draw of the screen, which you'll need to know to get a hefty enough adaptor. The rating will be in amps (A) or milliamps (mA), where 1000mA = 1A, and you'll need to make sure your adaptor meets or exceeds whatever the screen wants. It'll be in the documentation somewhere, or possibly written on the back.

Once you have your adaptor, you'll have to cut the plug off it and connect the wires that way, or attach a suitable socket to the bare wires you've got. Because it's a DC system, it's polarity sensitive, so you need to make sure you connect positive (red) to the positive wire from the supply and negative/ground/GND to the other wire. A multimeter is handy here.

If you don't know what any of this means, I suggest asking someone else to do it for you. If not, read up on power supply symbols here, find out how much current your screen needs, get a power supply to suit, wire it up, and pray

Good luck,
Gadget

seoirserob

Thanks for the reply. Found a 12V adapter, solid and dashed line present, no mention of amps on the device though. will try tonight. From what
i can find online there doesn't appear to be a convention for positive/negative wires coming out of the adapter. one has a dashed line running along it. I seem to find different opinions as to which is which.

There is however a fuse before current reaches the device, and I have a spare.

Thanks again.

seoirserob

on closer inspection it would appear that the dashed line running along one wire represents negative . . .

Inspector Gadget

A fuse won't help if you connect it backwards. Only a polarity protection diode inside the device will stop you from potentially doing damage. I'd say go buy a cheap multimeter - it's possible to get a cheap one from eBay for a couple of quid that'll do the job.

seoirserob

Alright . . . You speak sense. I'll ask a mate of mine and buy one if I have to, I suppose, no point in going gung-ho and frying the thing.