Wiring 101 for lighted buildings

I admit to knowing nothing about electricity and I find it a little intimidating as I build my first layout. I have DCC but am putting in a separate bus for lighted buildings and accessories. I intend to use an MRC power pack for it. I have a couple of questions that may be basic to most.

  1. Can I hook the accessory bus to the track part of the power pack and use the speed control as a sort of dimmer switch?

  2. I’d like to be able to run the wiring from the individual lights to a terminal strip of some kind but then have only one set of feeds going to the power bus. I’m trying to avoid a one for one ratio of lighting wires to connections to the bus.

  3. If I’ve purchased lights that were designed for buildings, do I have to be concerned about resistors and/or wiring in series? I’ve read the terms but don’t know what each is.

I’ve read several articles about wiring lights but each assumed a higher basic level of knowledge than I apparently have. Thanks.

To answer your first question - I have NO IDEA [:slight_smile:] I have never tried that before. I have just always used the “AC accessory” side of power packs for lights. I’m sure some of the other great minds on this forum should be able to tell you if it will work.
Question 2 - As long as 1.You use wire that is of sufficient size (or gauge). 2. The power pack you are planning on using can supply the necessary current. Then there should be no reason why you could not wire the lights that way.
Question 3 - This one is hard to answer. There are a lot of variables involved. If I had a little more info. I might be able to help you. I would need to know a.) the voltage rating of the lights you are using, and b.) the output voltage of your power source (power pack). If you can provide the above info. we can home-in on the anwser.

yes, assuming the power pack is not being used to power anything else.

Ok, but that sort of defeats the purpose of having a bus. The idea of a bus is that everything just connects to it with as short of connections as possible, reducing the total amount of wire.

It depends, but I think on the simple level the answer is no. What you have to be concerned about is what voltage and wattage they are. Ideally you want to provide power that is slightly less than the rating of the light bulb. A 12 volt bulb will burn brightly at 12 volts and eventually burn out. At 10 volts they won’t burn so bright (which is usually also a good thing) but they will last forever. The variable track power from the MRC would work nicely for this. In this scenario you would want them all in parallel.

I am afraid that if you don’t understand the articles, it is going to be difficult to describe things in the limited space and capabilities of this form. But all is not lost…

Have you already purchased these lights or are you thinking about buying them? Could you give the brand and model number, or post the specifications? The model o

Thanks for offers to help. The lights that I have are out of the package and not marked in anyway. If I have to buy new lights it is no big deal. I only have a few of these anyway. My reason for wanting to use the terminal strip concept is that the guage of the wires on the lights is very small. I’ve been using self-tapping connectors to wire the track to that power bus. The wiring on these lights is too small for any connectors that I have and I really don’t want to be soldering all of these 22 or 24 guage wires to the bus.

If anyone can be me some basic guidance on lighting for buildings that would be great. Recommendations on a specific manufacturer would be helpful. I’m not interested in trying to build my own. I hooked up a sample light to the MRC twin pack and it seems to work fine but of course I have no idea how long the bulb will last.

Thanks, that is what I’m planning to do. I have a Digitrax Zephyr system for the operation of the layout. I also have a spare MRC dual controller power pack. I was thinking that between the two train hookups and the accessories hookup, I should be able to have three separate lighting and accessory busses on the single MRC.

Here’s my two cents worth. By using the the track connection the power pack is what I use. It will work fine. I also use 12volt grain of wheat bulbs placed high in the buildings so that what you see is the lit enterior and not the bulb. They are wired in parallel to feeder wires under the layout. Simply put, “series” means that a feeder wire is connected to one wire of the bulb,the other wire from the bulb is connected to one wire of another bulb and then the other wire of that bulb is connected to the other feeder wire. the current flows from the power pack through one feeder wire to the first bulb, then throught to the next bulb to the other feeder wire back to the power pack. Now if one of those bulbs burns out both bulbs will not light because the circuit is broken by the burned out bulb. We don’t want this. Also in a series circuit the bulbs in our senerio would only burn at 6 volts because the 12 volts from the power pack would be divided between the to bulbs. To help you visualize a parallel circuit, assume you have a section of track wired to your power pack. your bulbs have two leads or legs on each one. one leg of each bulb is attached to one rail and the other legs are attached to the other rail.Thats as simple as I can make it here. Now that I have everyone thoroughly confused, good luck, Ken

Definatlly wire in parralell like Eriediamond says. I’ve gone the cheap route by buying a string of those Chritmas rice lights and cutting them apart.($4 for 50 light string). Their only about a 1 volt bulb so they blow instantly if you hook them to the accessory terminals. I hook them in parallel to the track terminals of an old Tyco pack used as a dimmer switch. If one blows you know which one it is. If you want to dim 1 or 2 for some reason,you then only have to put resistors on those bulbs instead of all of them.
Just be careful not to turn the pack up all the way or you’ll blow all the lights.(and that REALLY blows). I recomend gluing some kind of limit block on the power pak so you can’t turn it past the desired level.
Hope this helps!
loathar

  1. I had to paint the inside of my buildings black so that the light wouldn’t shine through the walls.

  2. You might also light one of the bulbs up and let it sit for a few minutes. Test it to see how hot it gets. I’ve seen some plastic buildings wth melt spots in the roof because they got to hot. Remember it will be hotter in an enclosed building with no natrual draft than just sitting out on a work bench.

  3. Do your buildings to be lighted have open bottoms or flat bottoms with a hole deisghend to snap the lamp in place? If they have open bottoms, you might want to consider standard micro base bulb. These have screws on the socket so you could just run “bell wire” from one to the next in parallel. Plus you could also easily change the bulbs if they burn out, or you wanted to change lamp type.
    http://www.radioshack.com/product.asp?catalog_name=CTLG&category_name=CTLG_011_004_006_000&product_id=272-357

Varies. YES IF the “track part” is not also powering the track. NO if they are. Brightness would go up and down with train runing. The accessory terminal’s on the power pak are fixed, and generally AC. With a separate rheostat it might work. BEST to use a separate (used) DC suppy.

a terminal strip allows treating you lighting into separate sections, like for separate building’s.

Simplist is attaching to a single source - like 12 volts - which is in ‘parallel’.

‘series’ wiring is easy to learn, but more complicated than parallel’

Thanks very much for all of the replies. I’ve got the parellel concept now and as it turns out, that is what I was thinking I should do. I just didn’t know it was called parallel. I’m definitely going to use screw-in base bulbs. I have a test bulb set up and as I assemble a building, before I paint it, I use that bulb to test if the light will bleed through the walls. I will definitely use the tip about painting the interiors black on several of them.

One suggestion that I’ve heard over the years and have seen implemented is that for modelers ligting up items like street lamps, houses, and buildings, train station lights, etc., it would be better to have a separate power supply or powerpack for these accesories.

Modelers don’t have to spend a load of money for auxillary power supplies; the small, cheap 12 volt MRC powerpacks would work for a standard DC layout.

If you do use the power-pack track terminals, there are a couple of things to remember. The power pack is putting out DC, so it will drive incandescent bulbs (normal filament-type bulbs) just fine. However, if you put a LED in a building, then you have to be concerned with the “polarity” of the wiring - which side is positive and which is negative.

Be aware that your power pack may put out more than the rated voltage of the bulbs. Some put out as much as 16-18 volts DC, while the “standard” bulb is probably 12 volts. Your bulbs won’t last long at that voltage. It would be helpful to put a voltmeter on the terminals and mark the points where the voltage reads 8, 10, 12, 14, etc., volts. Once you decide where you will set the control knob, use a piece of heavy tape to prevent it from going any higher.

They come in a range of voltages from 1 up to 12. Using higher voltage bulbs would be much easier. They certainly are a cheap source of lights. You can operate them in series/parallel combinations. For instance, put two 6 volt bulbs in series and run them off 12 volts. Or four 3 volt bulbs in series on 12 volts. If one burns out, they have a resistance built into them which keep the other lights in the string on so they all won’t go dark.

So what is the consensus here, to light or not light your buildings ? The downside I see is changing the bulbs. You need to plan accordingly. Also not all buildings may facilitate lighting easily. I am just now starting to place structures and pondering whether to add lighs or not. I did buy some yard lights but their bulbs are more accessible than most buildings. Do those of you who have lighted buildings really use them much ? I am guessing bulb life isn’t good.

I think there were a number of exceptional Photo Fun pictures last week (or maybe the week before?) showing night shots with building illumination. If you ever run at night with the lights off, then you owe it to yourself to try interior illumination on some of your buildings.

Wow, it’s funny how things cycled through on this forum. I actually first posted that a year ago. As an update, I am lighting my buildings and I did use a separate power pack. I too want to use a dimmer switch to turn the room to twilight and then watch my layout come to life at night with lights.

I’ve been considering using LEDs instead of grain-of-wheat bulbs, because they use less power and last almost forever. On the other hand, the way LEDs are set up makes it difficult, if not impossible, to fit them into certain fixtures such as scale lampshades. (this would be for a large scale layout, so there are plenty of opportunities like that).

On the “third hand” it might be extremely difficult to replace burned out bulbs that are mounted in shades, etc.

Any thoughts?

OK, so now it gets a little more interesting . You can use a room light sensor to control your seperate PS for your building lights, so that when you dim the room lights, the building lights will brighten as the room lights darken more…very cool effect.

Lots of good advice here.

Other items:

  1. Incandescent bulbs will last longer on DC than on AC. In practical terms the difference is pretty small, but for bulbs running for long periods of time it is measurable.

  2. You can put a zener diode in series with your bulbs in order to keep maximum voltage to a reasonable value. then you never have to worry about burning out bulbs if you crank up the “throttle” too high. This is best for those who understand how zeners work.
    Try also a 12volt automotive bulb to drop about 12 volts off of the normal max of 14 to 16. The actual loss will vary somewhat with current draw.

I know I’ve mentioned this on other lighting related threads…but it seems appropriate here:

When lighting industrial buildings such as machine shops, warehouses, factories, truck terminals, auto repair bays, and locomotive shops don’t forget that many of these types of commercial businesses have been utilizing “flourescent lighting” from the 1950s onward through today.

http://www.microstru.com/Flourescents.html