Forums Forums Enthusiast Forums A - Z Gadgets & Tech 12v tranformer

hey all,
right im in the middle of setting up a tv screen and dvd player/ radio player all out of a car 12v system in the garage,
but i need a power adapter to run them off, the devices mention no sort of ampage, of course they need a 12v supply, but my question is what sort of ampage will i need from the transformer to run both.

If i remember rightly,if they have wattage on the back divide by 12 gives you the ampage

nope no wattage on them, checked thoroughly

Thats funny should have wattage on them.

what sort of tv is it?

Have you tried them working off a battery charger,a low amp one 8-11 amps

ive tried a small 12v battery, i want the transformer as small as poss, i have lots of them lying round so hoping to use one of mine,

tv's only one used for dvd players in car about a 10" if that.

No model number is there mate?

Careful, you should really use a "Regulated Power Supply" and it's unlikely the battery charger is regulated.

On my boat,all 12v. i have a 19 inch flat screen which is 40 watts that works fine with a little car battery charger.

Have the transformers got adjustable ampage,if so start off at about 4 amps see if it works if not adjust up till they work,if not wire them up to your small battery and charger.

As a rough guide the currant draw for each item has to be less than the fuse protecting each item.

The old Curtis monitor and dvd player I have say 3amp for both, there is a load of 12v 3amp or more power supplies about especially at the car boot sales.

If they are designed for car use (ie happy with 13.8V) then I've used a small car battery charger across a car battery, often letting the battery supply the power by itself at times.

wouldnt it be a whole lot easier to buy an inverter ?

i do think this is a question for Ohms Law ?

Sounds like a good idea!

Presumably, if they ran of mains, he would just plug it into the mains instead of wanting a transformer