LED lighting

The trick is to wire them in parallel. In other words run a pair of conductors like a "bus" all around where the lights are, and attached the leads of each LED to it.

Start with a rheostat source (or several), so you can control brightness (and heat), then branch out to several mini contact strips (one side is pos. the other neg.) to form clusters. Branch off the strips with your lights. That way all lights are solid wired to the source rather than in series and one fail doesn't take others with it. Make your source come in at the center of each cluster so lights at the far end don't suffer lower voltage issues. Try to keep all of your wiring runs of similar length.

By subdividing with several source rheostats, you can control lighting in different areas, so you can run you perimeter lights separate from your tarmack lights or centerline runway lights.

Good luck and have fun.

Bocks Suv, think of the leds & supply wires as a ladder with the leds as the rungs(steps) & the power wire as 1 vertical side of the ladder & & ground(return) as the other vertical side of the ladder. how many leds are you going to use as can use a 12 volt power adapter but need to know the milli-amps of each led?

Err on the side of big with your bus supply wires. Running low voltage DC takes big conductor area in order to kep resistance down. 

Something like an airfield dio should be easy. As suggested, run your two conductors out to each general area so that the LED lead runs are short. Use good sized guage copper wire for the supply wires. If you have the room, setting up a terminal block in sections is helpful and keeps the soldering to a minimum.

LEDs are a bit sensitive to current. I would not recommend a rheostat because if you set it too low a resistance, even momentarily, you could damage the LEDs.  Rather, unless you are very sure you know what you are doing, I would include the recommended current limiting resistor for the voltage you will be using, on every LED, and run everything in parallel on that voltage. 

If you have room under the diorama, I would suggest creating a simple circuit board.  Blank "bread boards" with pre-drilled holes for wiring and resistors & diodes make it a cinch to create individual circuits which you can control.  I built one for my Constitution and mounted it under the orlop deck.  It has 27 individual circuits with various resistors to control the amount of light from each LED.  I also use diodes to prevent any back current from damaging the LEDs.

Shoot me a PM if you need any help.  I have been doing this for years on pinball machines and several other dioramas.  I can give you links to buy stuff and even help you with a schematic for wiring if you'ld like.

Bob

Hello,

I'm new here but I wonder if I could suggest that you buy a large string of christmas LEDs, most of the wiring is done for you then, and you can buy soft lights etc, they come in various numbers of LED's and I have used these with some success on slot car tracks in the past for various projects, also LED strips are very useful, albeit the quality can be interesting on some, but they do also generally have a dimming capability and are pretty good to use with minimal wiring required. 

I hope that this sows some seeds of inspired thinking and doesn't upset the purist modeller who would wire these from scratch.

Anyway these are just a couple of quick suggestions.

Kind regards

Try Evans Designs for your leds. They are great to work with.