Building interior lighting

[Philip H]

So of the buildings going into my new layout, I want to add interior lights as follows:

• two small warehouse lobby vignettes
• Dairy Queen interior
• HVAC metal shop interior
• various front porchs and outside side lights

I have a separate bus for lighting and power accessories (like signals and grade crossings) that I can feed 12 volts through.  I'd prefer LEDs and was considering multiple 0402s.  Anyone got good vendors? to recommend? Good circuits to emulate?

[wazzou]

I would suspect if you ping your bro @wm3798 he'd be able to walk you through it.

[wm3798]

Here I am!
I recommend using a completely separate circuit for your structure lights, and a switch (or series of switches) that lets you turn them off and on.  I like 9v AC as it lets you be less fussy about wiring in your resistors.  (With DC, they all have to be in the same leg of each LED)  9v also lets you have the option, if you ARE fussy about those resistors, to use a 9v battery.  I used that trick on my Cumberland modules.  On a home layout, though, a wall wart leftover from some forgotten appliance will do, just read the output and make sure you're not too far off over/under the desired voltage.

You can buy LEDs by the handful from various sources via ebay.  I like to mix up light colors to represent different kinds of lamps...  warm white for incandescent, bright bluish white for flourescent, and yellow for soda vapor outdoor lighting.  Make sure the LEDs come with resistors, they usually do.

I've never understood how to "read" a resistor... the little color bands mean something to someone, but I've found that if I have a power source and an LED and a selection of resistors, I can trial and error my way to eventual victory.  I do know that the bag of tiny ones I have are fine for 9v, but overheat and burn out at the usual output of a power pack (around 12-14v) so you'll want to keep that in mind.

And another thing, which I'm hoping I'm not too late to recommend, is to build the lighting into the structure kit WHILE YOU'RE BUILDING IT.  It's much easier to make sure you have the correct distribution of light and conceal the wiring adequately before everything is glued together.  Consider that in your Dairy Queen, you want the lights overhead to illuminate the interior of the restaurant, rather than a glowing orb behind the counter.  I know I would probably skip my ice cream sundae if I saw that as I walked through the door.

Also, remember that exterior lighting is as important as interior lighting.  I use little 1.3mm LEDs to make exterior light fixtures.  They're the ones that have the little box with a lens popping out.  Bent at 90 degrees and painted black, they make good down lights to put next to a door or over a loading dock.

I'll go back and edit some photos back into this post for your reference.

Lee

[wm3798]

Some reference photos for your edifice-cation...

Here's a retrofit into a building group I originally built back in the 80s

I simply drilled holes in the roof and dropped the LEDs down from above.  Once wired in, I added roof air conditioners, hatches and various other crap to conceal the wiring.

The result.


Note that the street light is just an LED suspended from the wall.  In the final installation, I'll put a telephone pole in place to give it something to "hang" on...  I paint the wires going into the building black behind the pole, and light gray or silver in front of it to trick the eye.  Okay, so some gin helps too.

Here's a good example of mixing colors of light, and the outdoor wall fixture I described.  I don't think I had painted the head of the LED yet in this shot.  In fact, I've never finished that building kit... 



When lighting a larger building, I'll put in some scrap rail to carry the current to a bunch of lamps.



As with all things electrical, be careful to insulate the stuff that might get close together.  I find hot glue to be an effective and easy to use material for this once all the soldering is done.  And of course, you want to be careful not to cross the streams, Ray.  It would be bad.

The results:


A couple of more examples:









And this perforated vinyl drywall corner bead makes a great "circuit board"...


If you need the buildings to be removable, you can wire the lighting into a simple phone jack then daisy chain the phone jacks to your wall wart.



In the end, all the work will be worth it!
Lee

[peteski]

Resistor color codes are not rocket science. Any architect should not have any problems decoding them. 



But with the advent of Interwebs, when you are lazy or refuse to understand the codes, just use one of the online calculators, like https://resistorcolorcodecalc.com/

Tiny SMD resistors actually have the resistance value code represented numerically  (like "472" is "47" and two zeros, or 4700 ohms, or 4.7k ohms).

With a 12V power supply and a single white LED in series with a resistor, a safe range of resistors values is 1000 ohm (1k ohm) or higher.  Safe power rating of the resistor is 0.25W or higher.  With higher value resistances, you can go with 0.125W rated resistors.

[wm3798]

Resistor color codes are not rocket science. Any architect should not have any problems decoding them. 



But with the advent of Interwebs, when you are lazy or refuse to understand the codes, just use one of the online calculators, like https://resistorcolorcodecalc.com/

Tiny SMD resistors actually have the resistance value code represented numerically  (like "472" is "47" and two zeros, or 4700 ohms, or 4.7k ohms).

With a 12V power supply and a single white LED in series with a resistor, a safe range of resistors values is 1000 ohm (1k ohm) or higher.  Safe power rating of the resistor is 0.25W or higher.  With higher value resistances, you can go with 0.125W rated resistors.

It's easy to arrive at the numerical value that the color code represents, provided I have my readers on and someone helping me determine what colors I'm looking at... Red/Green color blindness has me looking at several shades of gray, rather than brown, red and orange, violet and gray look the same, and gold/yellow/green are pretty interchangable...  I guess I could photograph the assortment I have and someone could "read" them for me, then I can mark them down on a label.  My challenge is also relating that value to the other components in the circuit.

The information you provided is definitely helpful.
Thanks


As far as the applications go, ...Any good architect will tell you that we have subcontractors that figure that ***** out!

[kiwi_al]

Lee you can use a digital multimeter to measure the resistance, then you don't care what the colors are 

[peteski]

Lee you can use a digital multimeter to measure the resistance, then you don't care what the colors are 

Yes, that works even for color-blind people.    And a digital multimeters can be had for as little as $7.

And Lee:  I didn't know you were color blind. Like you said, that makes to color codes unreadable.

[wm3798]

It's a mild case, but the subtle differences mentioned, especially on a tiny resistor, makes it pretty challenging.

[peteski]

It's a mild case, but the subtle differences mentioned, especially on a tiny resistor, makes it pretty challenging.

I understand Lee. I have a good color vision, but as my eyes are getting older I often need magnification and strong light to read those stripes. And sometimes the colors they use are rather pale, or the background color makes deciphering the colors even tougher.  Fortunately I have mostly moved away from conventional leaded resistors, and nowadays I almost exclusively use SMD parts. Those have actual numbers on them, which makes things much easier.