I want to put lighting inside some structures I have that were not purchased as illuminated buildings. Is this a safe practice? Is it ok to place a small bulb inside a plastic kit house or a store
without melting or otherwise damaging the structure?
1. Plan the installation so that you can eventually replace the bulbs - they DO burn out. I always make a plastic base for my buildings to sit on, then secure this base to the layout. The building is
held in place with plastic strips along the inside of the walls. I can just pop the building off if a light burns out, and the base makes for a good light seal along the bottom edge of the wall. The
wiring runs through a hole in the base to under the layout.
2. You'll rarely see a building with all it's lights on, so you need to add interior light blocks so that all the windows aren't lit. These interior "walls" can also screen the inside wiring. If you
get creative, you can use one bulb to light several different rooms, with dark rooms in between.
3. You can use plastic piping to run wires around buildings and hide them or suspend lights from the middle of a room.
4. Nothing looks worse than exposed wiring or an exposed light that you can tell is just a light bulb. Disguise and hide them.
5. Dim is almost always better than bright, except in specific cases like industrial outside lighting. Most real night lighting is very subdued. Experiment with bulb size and color, reduced voltage,
etc.
Mike Tennent
Mike: I havve most of my buildings lit with "grain of Wheat" bulbs wired in series pairs. That halves the input and gives a nice yellow glow without excessive heat.
Lester
Is it possible to do building lighting in parallel instead of series? It seems that by doing it that way a person could select a power source (voltage would depend upon the bulbs used, I guess) and
run a pair of wires (+ and -; or maybe 2 or 3 pairs if you wanted several circuits that could turn on or off separately) along the length of the layout. Any time I wanted to add an additional light,
all I would have to connect a bulb (of the proper voltage) to the + and - feeds and be set. As the lighting on the layout outgrew the power source, I figure a person could just get a new power source
of the same voltage but higher amperage to meet the new lighting requirements.
Since it sounds like most people use building lights in parallel, I figure I must be missing something basic with this idea.
Mark Mathu
Actually, what most modelers I know do is to wire the lights in a particular building in series, but wire the buildings in parallel. I think your idea is as good or better than that.
Jack "The trolley nut" Priller
It sounds like you're instituting "bus" wiring, similar to what lots of folks use for their track wiring.
The one thing you have to remember is that eventually you reach a point where you can't simply add more power to make up for the number of bulbs. And you'll get there sooner than you think.
Through experimentation, I've found that thirty 12V/16V lights (driven by a 12V,1A source) is about all I can put in one circuit before it gets too dim for my personal preference.
For some circuits, say industrial lighting which you want to be powerful, thirty is way too many. Wallwarts (plug-in power supplies) are cheap, so it's feasible to segment off your layout into zones,
each one with it's own wallwart. Your "bus" idea would work for each zone.
Mike Tennent
For figuring out the power supply, suppose the lamps are 12V grain-of-wheat bulbs using 60mA each.
If I've got 30 bulbs on my layout, I'd need 30 x 0.060A = 1.8A of power. So I'd select a power supply of constant 12V, 2A max to power the circuit. Wiring things this way seems to have the following
advantages:
+ The main power feeds (the heavy red and black wires shown in my diagram) can be installed when the layout is constructed. The feeds can run the whole length of the layout, even to areas that may
not get lighting until a later date.
+ Every bulb is getting the same voltage, so they will all burn at the same intensity. (Is that really good or bad? I'm not sure.)
+ A burnt out bulb will only affect itself; all the other bulbs will remain lit. On the other hand if a bulb wired in series was to go out, all the other bulbs in the series wouldn't work,
either.
+ If you want to add additional lights to the layout all you have to do is tap the power feeds in the vicinity of the new light location. There's no need to run the lighting circuit all the way back
to the power supply, since the power feeds are already doing that for all of the lights on your layout.
+ As long as all of your lighting effects use the same voltage, you can mix different amperage requirements in the circuit with no adverse effects. So you can mix strobes, flashers, what have you
with your plain lighting.
+ If the lights in the circuit become too many for the power source, you can just add a second power source to the existing circuit. Just select another power source with the same voltage (12V in my
example) and connect it in PARALLEL with the first power source. Both power sources woul be putting out 12V potential. Heck, the second power source wouldn't even need to be at the same location on
the layout - you could locate it a the far right end of the circuit diagram if you're worried about voltage loss at the far end of the layout. (But it would probably make more sense to have both
power supplies in one location so they can be turned on and off simultaneously.)
Mark Mathu
You can put two power supplies in parallel IF both are IDENTICAL. If not the same output and performance under load, the supplies can end up "fighting" each other. I recommend that you break the
circuit and add another feeder. Also, be concerned somewhere in the future about trying to handle too much current on your wires.
As load is added (in this case lamps) the power supply will/may sag - the voltage drops down some and the lights get dimmer. The ultimate is that the power supply output is effectively shorted and
nothing gets out but smoke.
If you plan to have lots and lots of lights and other 12 V accessories, break your layout down into "districts" with approximately equal power requirements. Then feed each district with its own pair
of wires fused at the power supply end for protection. Kind of like the wiring in your house.
Bob Schwartz
Another aspect of this might be economics. Looking in an older Jameco catalog, a 12V, 2000 mA wallwart is 13.95, a 12V 1000 mA is 9.95 and a 12V 500 mA is 5.25 (3.95 with just stripped wire - no
connector plug). Since we now know that we can't burn an unlimited number of bulbs from one power source, (w/o significant dimming at some point), the question becomes can you burn three times as
many bulbs off of a 2000 mA power source as you can off of 3 500 mA sources?
And I wish I had those three power supplies so I could answer that. My guess is that you's burn more bulbs brighter with the separate smaller power sources than with the one big one. The best thing
to do, of course, is experiment and see what different set ups look like. Buy a bunch of lights and connect them in various ways and power sources and see what each looks like and which you like the
best. There's no single answer.
I do think that if you want more intense lighting (modern street lights or industrial lighting in a specific scene), you'll probably be happier with a separate source for those specific areas. Modern
industrial lighting and some business lighting is much brighter than the street lights surrounding them. If they're all the same brightness, you lose realism. Using a different power source for each
scene is one way to match the brightness to the specific need.
You're overall concept is valid, but I think you'll be disappointed at the brightness of the lamps if you get into a significant number on one circuit.
Mike Tennent
You should be OK with small lights in buildings unless you place a 40 watt household bulb under one! The plastic in most model structures is thick enough to withstand the small amount of heat a
small bulb puts out. The problem you may have is that the light will show through the plastic on some models. To remedy this, just paint the insides of the walls black.
Shane Lambert
I don't see what that would be a problem. UNLESS... you are talking about 120VAC bulbs (220VAC) in europe) If you use these. Remember to keep the wattage low. I would say a 2Watt bulb would be
fine.
Since some polyStyrene allows ligh to pass through. you don't want your walls to glow do you? You need to paint the inside flat black followed by a coat of white. This prevents the glowing walls. The
best and safest lighting is Christmas tree bulbs of the low voltage type. Safest as they are cool and pose less of an electricution hazard.
B'ichela
Why both? Why not just a coat of either black or white?
White alone probably wouldn't prevent the ghosting...And no-one has black walls unless they have a teenage son.
Mike Tennent
When I install 12 volt lights in building, because of the heat they give off, I but some metal duct tape on the inside of the roof. This acts as a reflector of both the heat and the light and is
cheep. The tape is available is home stores like home depot and looks like heavy allumium foil tape about 2" wide. IT also works great in locos also.
gcoug
I model in N and prefer to use Yellow LEDs for interior and exterior lights. They don't give the glare that incandescent tend to. Some of the LEDs available look like light fixtures so I paint the
non-lit parts of them silver, black or some other color and poke the leads through the plastic structure. Inside the structure I like to use an adhesive backed copper tape for the wiring and super
glue the LED. When I'm done wiring the building, I tape off the light emitting portion of the LED and airbrush the interior grey. This both eliminates the light glowing through the walls (which LEDs
don't tend to do anyways) and finishes the interior.
Clark Martin
There is an old Model Railroader article about using printed circuit board material (un-etched) as a base for a town. You cut grooves in the copper to make "traces". You wire your lights to the
traces and set your structures down on the PCB material. There is also copper wire tape that you can stick to the inside of buildings hiding the wires running in the buildings. You can paint, paper,
or scenic over the tape. It will disappear. To connect just puncture it and push the wire through it.
Clark Martin
I'm ALWAYS struggling with what to do about the glazing (plastic) in windows - sometimes I tape them and paint. Sometimes I paint, then scrape a little plastic off and glue. Usually I forget and
have to go back and re-do something... Out of curiosity, how do you do it?
Mike Tennent
For building lighting, I've blocked off some windows with black electrical tape to simulate unlighted rooms. Covering some windows on the inside with "magic" frosted tape disguises the fact that
there isn't any interior details. This way a single bulb can light the whole structure, and all windows are lighted in a different manner. Don't forget the window blinds (I used masking tape) and
curtains.
In a building on the edge of a layout, I fastened a color slide on the inside of a larger window. I made a small box to place behind the slide, and mounted a small bulb inside to illuminate the
slide. Nosy viewers who look in the window will see a photo of our modular group setup! This light box was made without a bottom, so the light shines on the "floor" below. I made a small room here in
which I placed some Preiser figures of an artist and a nude model - this gets noticed!
Bob Boudreau
I read that some people use fiber optics for house lighting. It produces no heat, so there is no chance of melting any plastic. It is also easier to install, reduces the amount of wiring, requires
no resistors, and eliminates the hassle of changing burnt out bulbs, since the only bulb providing light is outside of the structures. Has anyone done this? Would this be a better alternative?
Fiber optics are good for particular effects, but not good for general room lighting - they don't usually produce enough to light a room, except dimly. In other words, they're effective when they can
be viewed as a light source - lights in a sign, car headlights, tail lights, etc, but not as a source of general illumination for a scene.
One thing that helps fiber optic light intensity is to create a "mushroom" tip at it's end by heating it gently with a match and then pressing it quickly against a flat surface. The "mushroom" helps
disperse the light.
Mike Tennent