L E D in to a model

[caretaker]

I am putting some LEDs in to a model about 30, now have I got this right.
From a 3v regulated transformer red/positive wire to switch from switch to the positive side of LED, from LED negative to negative side of transformer.
One light wired, repeat with other 29 LEDs.
The transformer has settings from 3v to 12v.
The model is wooden but sorry about it being electrical question.

 

[nev]

http://www.instructables.com/id/LEDs-fo ... ers/#step0

 

[MMUK]

What colour LEDs? At 3v they WILL require resistors but the value depends on the colour and forward voltage.

 

[RogerS]

And this is helpful

http://electronicsclub.info/leds.htm#calculate

 

[Racers]

I would get a reel of 12V leds from Ebay, they have the resistors fitted, it will be much easier only one connection!

Pete

 

[caretaker]

The model is a house but not a dolls house as you can only see in to the rooms through the windows and doors, the ground floor when finished will have seven rooms plus a large hall with a grand stair case, the smallest room is 4" x6" inches and there will be two floors with an attic.
I will be lighting the rooms with LEDs as this seems to be the cheapest way, the LEDs will all be white and individually switched.
Now I am at a very early stage but as there will be limited access to the rooms later I need to run the wires and fittings as I build.
This project was recommended by my specialist to help with the limited use of my left hand.
Perhaps in a year or two when finished I will post a photo.
Thanks for all help and suggestions Reg

 

[RogerS]

What a super project, Reg. I reckon you are going to make a granddaughter (I am guessing) a very happy person.

This site is what you need. http://www.expressmodels.co.uk/acatalog/WHITE_LEDs.html

They have really small LEDs aimed at models plus they have built-in resistors that will save you time plus they have long wires which should also help plus they have a range of whites including warm white which might get closer colour-temperature-wise to normal tungsten bulbs.

The one thing that no-one has yet mentioned is that a transformer by itself is AC. LEDs need DC.

EDIT: This cheap power supply from Mapiin should do. You won't need your transformer. http://www.maplin.co.uk/p/12v-3a-univer ... tips-a92jh

 

[MMUK]

I think the transformer the OP is referring to is one of these switchable DC output plug in types you get for a fiver from B&M and the like.