Grandpa Lee's Miniatures
How To electrify your doll house One of the most dramatic effects you can add to any doll house is electric lighting. Almost all systems use well proven, safe, 12 volt, low amp current. For example, only the most sensitive people can feel even a slight tingle if a 12v, low amp current were to pass through say, a damp finger. But as an added safeguard some folks choose to install a low amp fuse which is fine although we're not going to fuse the house we're building here. Nor for that matter have I seen fusing promoted much in any of the literature. If you do inadvertently create a short circuit while wiring your house, as most of us do a few times, the fuse in any such fused system will blow instantly so keep several fractional amp spares on hand. Without fusing, the most you might see at the point of the short is a very tiny spark. This might be startling, but poses no real safety hazard as these shorts are almost always just momentary. However, in the very unlikely event any short is allowed to continue, small diameter wiring and the transformer will begin to warm up.
Some definitions This is perhaps the longest and most technical of all pages, but be patient and we'll get through it OK. But first we need to deal with a little terminology. All lights get their power through electrical conductors of some kind. We'll be using flat two conductor tape, insulated on both sides with adhesive on the underside so it will stick to the wall. Both parallel conductive bands are copper but one is colored blue to minimize confusion that could result in a short circuit. 12 volt power comes from your normal house current through a wall transformer that steps down regular 120 volt AC house current to a safe output current of 12 volts, either AC or DC, either of which works equally well in doll houses. These transformers are essentially the same, and just as safe, as those you now use to charge such things as your cell phone, and your electric screwdriver. Transformer line switches are also available if one wishes to leave the transformer plugged in because the outlet may be hard to reach or because the doll house lights will be turned on and off frequently. For only occasional viewing it is probably best to just plug in the transformer only as needed because even with the lights off these transformers continue to draw enough current to stay warm. Note: 12v transformers besides coming in either AC or DC output current also come in several amperage ratings. A general guideline is; use10 watt (250ma) for up to 16, 12v bulbs, 20 watt (500ma) for up to 33, 12v bulbs, and 40 watt (1.0amp) for up to 66, 12v bulbs. Ultimately, brass grommets are
inserted, one through, and in contact with, each copper band making up either an outlet for little two prong electrical plugs that function just like full size appliance plugs or for splices when extending a tape run or when changing tape direction. We're going to call the main electrical tape the bus line. Connected to this bus line are both trunk lines serving as spliced bus lines to intermediate floors, and intersecting branch lines that go off in other directions to eventually connect with feeder lines where outlets are finally installed. A single run of electrical tape is best folded to go off in another direction, but tape intersections where necessary are made with splices. Connecting to the transformer is another type of electrical connection we'll be discussing.
Just like a real house It's funny the way these kits mimic real house construction. You have to plan and layout the wiring just as it was done in your home. We're using conductive tape because on balance it's a bit more convenient than wire, but wire is often used and there are significant pros and cons associated with either system. Perhaps by this time you've even accumulated an assortment of instructional information on various ways to wire your kit. I'm going to ask you to forget about most of it for now and follow along with the system I've evolved after a lot of research and experimentation. First decide and mark the walls exactly where you want all your outlets, ceiling lights, and optional sconces or coach lights. An effort should be made to position wall outlets vertically to appear natural. This happens automatically on horizontally running tape as shown here. Carefully draw this plan on paper and put it in a safe place as you will have to rely on this "map" later to locate tape runs for the installation of outlets once the wallpaper is in place. Let's ignore flickering candle lights and fireplaces for the moment as these appliances require separate, additional transformers.
Where's the juice? Next, if you use the method I prefer we have to install the main circumferential bus line starting in the "crawlspace" and passing through the floor into one lower open side of the doll house and continuing on a journey all the way up one open side of the house through slots sawed in the edge of each floor until finally ending in the attic. These small slots are made with a hacksaw blade and will eventually be covered completely. Structural integrity of the house is not compromised in any way. Internal tape
patterns can vary somewhat but plan out the most efficient path as this tape is very expensive. Apply all final horizontal conductive tapes about 3/4" from the floor as shown above so your outlets appear to be properly scaled for the room. Once the bus line is in it can be connected to the transformer. Place looped wires of different lengths from the transformer around similarly offset and partially inserted grommets. Hook solder around these grommets and press them in fully for soldering as described next. The offset is to be sure exposed wires cannot touch each other. Alternatively, they can be spread apart somewhat to avoid touching. Insulate these connections by covering with a small piece of Scotch or electrical tape as an added safeguard.
Splices Follow the rest of your predetermined tape pattern, making overlapping splices where required. Make tight inside corner tape bends, and note that if some of the tape is already stuck to an adjacent wall you can easily break the tape by trying to force a loose bend into a tight corner. By now we're almost ready to make trunk line splices. Drilling recommended pilot holes and simply pressing in grommets for both splices (unless brads are used) and outlets is the conventionally recommended procedure and is generally considered to provide 99+% reliability. For the sake of simplicity you may be satisfied doing it this way. The grommets used for splicing feeder lines will never be used as outlets (shown here on the left). Therefore, spacing is not important other than to be sure that all overlapping splices are only made between the same colors to prevent a short circuit. Splices are also routinely made with small brass brads but they are hard to use, not entirely reliable, and I never use them because the slight extra cost of using standard grommets for reliable splicing is insignificant.
Outlets The only two, but very important differences when installing outlets are that now each grommet for an outlet will pierce a different color on only a single conductive tape with the holes squared up and spaced exactly for matching little male lamp and appliance plugs. The photo above shows an outlet (on the right) next to the splice on a bare wall for purposes of illustration but outlets are better inserted in the same way after
the wallpaper has been put on. If you want to get really fancy, you can even install wall switches to control individual outlets, chandeliers, and other fixed lights but that's a little beyond the scope of what we're trying to do here. In the model we're building all lights will go on and off together.
Playing it extra safe However, peeling wallpaper later to fix a broken connection is not fun, and to rule out any chance of ending up with a dead outlet because one relied entirely on frictional contact alone (sometimes even faulty outlets and splices work for a while), I feel that if you have the equipment and feel comfortable doing so, that taking the extra time to solder all joints is well worth the effort. The only certain and reasonably convenient way I've found so far to make a perfect soldered grommet is as follows; Using a #53 (.059-a size drill- slightly smaller than recommended) drill through the tape, making sure your spacing and alignment are right and through a depth sleeve to prevent piercing the walls. Flatten back the small copper craters that result when removing the drill with a dowel end or some such. Then coat the grommet shank with flux and partially insert it, hooking a small loop of thin wire solder around its head before fully seating it to trap the solder loop as shown here. Then simply press a soldering iron that has not been tinned (to avoid soldering the hole shut) straight down onto the grommet to seat it fully and the process is successfully over as soon as the trailing solder wire melts free. Splices as shown here are done on bare walls but remember that the final outlets are best installed through wallpaper which is not shown here for clarity, and as always, test often as shown below to validate. Note the tape passing through the slot from the floor below as described.
Final touch Test every line extremity as demonstrated by this small test light which is available at most hobby shops for around $5.00. If anything is wrong this is the time to fix it. This is also the time to
install internal partitions. If additional outlets are desired on internal partitions, splice to the most convenient conductive tape and plan to install needed outlets as desired after all the rooms are papered. Using your "map" along with a test light as shown here will assure that you pierce the right conductor before you drill through the wallpaper later to install the final outlets. Additional outlets can be added any time in this way to existing lines after the house is finished. Note: We are not going to review special ceiling light adapters here nor do I recommend installing "hammer in" lights unless tight accommodating pin holes are first drilled for easier installation. Attic lighting is another special headache all its own. The easiest way to get around wiring over odd inside angles in the attic is simply to glue in a false wall partition or ceiling panel in order to "square things up". This process is seen and explained in detail along with more information concerning decorative outlet treatment in our "How to wallpaper" page.
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Grandpa Lee