electric latch and keypad

[redface]

i have been asked for a 12v supply to a electric key pad and latch to a gate now what im asking is can i have transformer inside and run 7 m to the key pad i think it wall draw 1 A max but i know that there is a lot of volt drop on 12 v i was thinking of just putting 1mm tw/e from transformer the transformer will be supplyed from a socket to fused spur to tformer.

what size cable in 12v side?
what transformer ?

 

[bugsy]

what manufacturer, they normally supply their own PSU's