I made a drawing of the circuit. Minimal circuit. Some people use a 10ufd electrolytic capacitor between pin 1 and common/minus side. RS has the capacitor.
I added a series diode to protect against accidental DC reversal, read not paying attention, to the polarity of the applied DC voltage. The diode drops only .7 volt from the 9 volt wall wart.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
go to www.visi.com/~spookshow/lowvcircuit.html he gives a hole list of parts needed to light up alot of lights like 30ish off one power saply
dale8chevyss A strand of Christmas bulbs works well for me.
A strand of Christmas bulbs works well for me.
What a great idea!!
cooltech
Most transformers have accessory terminals. The esiest way I think is to run your wires from each terminal, (there will be two), under your platform to structure areas. Having purchased lights from a hobby shop, one wire goes to each of the wires from the accessories. Kind of like diagram below. The vertical lines represent the wires from the bulbs. I cut a small hole through the platform where the structure would sit and dropped the bulb wires through to connect to the access. wires. I cut insullation away to connect bulb wires without having to tie wires at each accessory. See second diagram. Each vertical line reps. another accessory.
-----I--------From access. 2nd diagram. --------l-------l-------l---
-----I--------From access. --------l-------l-------l---
I also try to use a seperate transformer so the lights aren't affected by train operation causing dimming of lights. A cheap one will do the job. Hope this helps.
As was mentioned, running incandescent lamps at reduced voltage increases their life. The life varies as the inverse twelfth power of the applied voltage! I run 12 volt lamps at 9 volts and can expect a 32-fold increase in life. I expect I never will have to replace a lamp.
John
Lots of good advice here. I've been into electronics for work and play for over 50 years, and still made notes of many of the suggestions. For my 2-cents worth: Decide on a lighting voltage and lamp mounting before starting and stick to it as much as possible. I decided early to light most of the structures on my layout. I found a good deal on some 6V bulbs with leads to start. Later I found a special on 12V bulbs with sockets. Then fell in love with LED lighting. Saw a special on 16V bulbs with adhesive base and leads. etc, etc. I now have 7 different power requirements, 10 if you count animation power, and only a few of them work because of the complexity of wiring and powering such a mess. Still having fun, though!
I've tried that before and all it did was blow the fuse in the power supply. Something in the electronics doesn't like partial power. Those dimmers are designed for use with lamps and such, not electronics.
Dr. Frankendiesel aka Scott Running BearSpace Mouse for president!15 year veteran fire fighterCollector of Apple //e'sRunning Bear EnterprisesHistory Channel Club life member.beatus homo qui invenit sapientiam
Thanks. I never touch anything that's 120 volts. Scares me. But I have an inline dimmer (if that's the correct term) around here somewhere that has a regular 120v wall type plug on one end and a regular plug in socket on the other. I bought it years ago at Lowes and never used it for anything. If I can find it, it seems like the risk to me should be low. If I blow out the transformer, so be it. I've got several more that are just taking up space.
- Harry
HarryHotspurust out of curiosity, what would happen if I wired an ordinary household dimmer between the 12v computer power supply output and the string of 2.5 volt Christmas tree bulbs I'm planning to use in my structures? Would that work?
I can't say I have tried that but just off the top of my head I would say it won't work well at all and might harm the supply. What is generally done with low voltage household lighting is to install a dimmer on the line, (120V) side before the transformer. You could try that I suppose by wiring a dimmer to the outlet the supply is plugged into. Just be careful not to illuminate yourself! If you are not experienced working with line voltage don't do it. I don't want to read about you in the papers.
Thanks Kevin. That looks like something simple enough that I might be able to build it. Just out of curiosity, what would happen if I wired an ordinary household dimmer between the 12v computer power supply output and the string of 2.5 volt Christmas tree bulbs I'm planning to use in my structures? Would that work?
BTW, I think I know how to wire the bulbs (about 50 of them) in a combination of parallel and series such that each bulb gets no more than about 1.5 volts. I've tested them with an old MRC power pack and they seem to work fine.
HarryHotspurIf I used an old computer power supply (and I have plenty of them), what would be the best way to add a dimmer in the circuit?
Rather than adding a dimmer I think you would have to make the power supply a variable supply.
Something like this maybe?
http://www.wikihow.com/Add-Variable-Voltage-to-Your-ATX-Based-Bench-Power-Supply
Thanks. I wondered about that. Seems like there would be a cheap dimmer to put on the 12 volt side of the power supply available somewhere, but I really don't know what to look for. I guess I should ask in the Electronics Forum.
I tried putting a dimmer inline between the wall socket and a computer power supply once. You don't want to go there. You can put it on a dusk to dawn switch but a dimmer just doesn't work, at least it didn't when I tried it.
If I used an old computer power supply (and I have plenty of them), what would be the best way to add a dimmer in the circuit?
That looks terrific, Mr. B.
Thanks again. So many great ideas! Think I am ready to give it a shot, once the market rebounds and I can afford a wall wart!!! Mr. Beasley your photo card interiors are an outstanding idea!
I know this may sound very primitive but I have had great success with Chistmas lights! One string has about 150 and my layout has plywood base with foam board cover. I mark were the building will be then drill small hole to fit the bulb thru. Tape the bottom so it won't slip out and that's it. I do use individual lights hooked up to to a bus line powered by an old train set poer sully that works great for the main street lights.
If you get lucky, you can find a connector that matches your wall wart DC connector. Radio Shack maybe. Or cannibalize the connector out of what ever the wall wart used to power. If the connector can be obtained, I would use it; when doing maintanance, it's always nice to be able to take things apart without having to solder them back together.
Coming back to real life, you may not be able to get a connector to match the wall wart. In that case, you can snip off the wall wart's connector and splice the wall wart wire to your under table lighting bus. Or you can use a barrier terminal strip. Wrap the wall wart wire and the lighting bus wire around the same screw head. Polarity doesn't matter, just so long as the lights are incandescent lamps, not LED's. LED's do care about polarity which is one good reason not to use them.
One good way to splice wires is strip the insulation, twist them together and then solder the joint. Then insulate it with heat shrink tubing, or plain old plastic electrical tape. Or, use wire nuts. Or use crimp on inline splices which a good hardware store will have.
If you want to switch the lights on and off, simpliest is just plug and un plug the wall wart. If you want a switch, consider plugging the wall wart into one of those switched power strips the computer stores sell. Or, plug the wall wart into an ordinary extension cord, and then install one of thise in-line switches such as are used to switch table lamps.
David Starr www.newsnorthwoods.blogspot.com
This works well on some buildings. These are cheap bulbs and sockets I got from IHC. I think they were about 50 cents for the bulb and socket, with pigtail wires included. The flat-based socket can be glued to the layout base, so you can lift the structure off and leave the lighting and wires in place. If the bulb burns out, it can be simply unscrewed and replaced. (I took this picture before I punched the hole through the base and mounted the socket permanently.)
It's important the bulb not be visible through the windows. That produces a bright point light source which is really annoying. Here, I shielded the bulb with a piece of cardstock. I printed up pictures of store shelves on cardstock and used that to make an interior for the building. This makes a difference if the building is right in the front of the layout, like this one, or if it has big windows. The floor, once again, is printed on cardstock. The cardstock interior can also be glued to the walls to further block glow-through, particularly in structures made of thin plastic.
The second-floor window shades are made of tissue paper. I didn't light the second floor, so I put a piece of styrene between floors. The window shades make it hard to see into the second floor, so you don't notice that there's nothing in there. The window signs upstairs (Dewey, Cheatham and Howe, plus the R Crumb Trucking Company) are home-made decals applied to the windows.
It takes an iron man to play with a toy iron horse.
tarhawkDo you then have to plug/unplug the wall wart to control the lights? Thanks again to all for a really great collection of tips on this!
Thanks David, that is the approach I plan to use. I think I "get it". I am using a bus line for my track DCC power so I have a little experience with that concept. What I am not clear on is how to use a wall wart as a power source ie how do you connect the 2 bus wires to the fairly short wires from the wall wart. Do you then have to plug/unplug the wall wart to control the lights? Thanks again to all for a really great collection of tips on this!
Consider that you may want to remove the building from the layout for maintenance, repair, upgrading, whatever. The optimum solution is a connector for each building, so you can unplug the building and take it up. This works if you can afford the connectors. The other plan is leave enough slack in the wires so you can just snip them and later strip the insulation back and solder them back together. After all, you don't take buildings up for maintanance every day...
Assume you will want to light several buildings off the same power supply. I'd run a 2 wire lighting bus around under the layout. #20 or better wire. Plain old lamp cord is #16, that thin speaker wire from Radio shack is #20. Tap each building off the lighting bus by stripping the bus wire and wrapping the wire from the building around the bared bus wire and soldering. This is called a "Tee" splice. Stagger the Tee splices so they won't short together. Connect the power supply to the lighting bus by splicing.
Also, look into the Christmas tree lights. They are cheap. It's OK to have some of the un used lights in the string just tacked up under the table.
The old trick for extended bulb life is to run the bulbs a couple of volts below their rating, ie run 12 volt bulbs on 9 or 10 volts, or 14 volt bulbs run on 12 volts and so on. It doesn't change the light output much, but the bulbs will last *** near forever.
The below links are about doll house lighting. Many possibilities for model railroads.
http://www.google.com/search?hl=en&q=doll+house+wiring+copper&btnG=Search
My approach is to make a ceiling type light fixture (not detailed) using one or more grain of wheat bulbs. I connect the bulbs in parallel so that if one burns out the whole structure doesn't go dark. Then I connect a 100 ohm resistor in series with the bulbs. I put all of this inside the building and mount the bulbs so they are at approximately the locations where a prototype structure would have lights. This gives me two wires to connect to the accessory buss (16 VAC).
Sometimes I vary things a little by connecting combinations of resistors in series and/or parallel. This makes the amount of light vary from building to building.
The reason for placing the bulbs in the correct locations is so that any light that projects through windows will be projected onto a realistic location.
Phil, I'm not a rocket scientist; they are my students.
There is a lot of good information that has been provided already. This is what I have done. I have a 12v system on most of my lights. The power comes from the accessory connection on the throttle transformer. One wire of the buss is a common wire and the other side of the circuit goes throuth 3 switches which control sets of lights. The 3 sets are: buildings which would have lights in the daytime only (ex. hardware store), buildings that are open during daytime and evening (ex. restaurant) and items which are only on at night (ex. street lights). I use 12v and 16v bulbs. The 16v bulbs are for places that do not need to be as bright (these bulbs should also last longer).
I also have a separate switched 1.5v circuit powered by a wall wart. I use this for porch lights on some of my houses.
As has been mentioned be sure to paint the inside of the walls and seal the joints so light does not leak through your buildings. Leave some windows dark (you could put black construction paper on the inside). In houses you can cover some windows with curtains or shades (ex. bedrooms) so that they glow with the light inside.
A couple of links I had... so many seem to be dead links since the "upgrade".
http://cs.trains.com/trccs/forums/p/113175/1300995.aspx#1300995
http://groups.msn.com/TonysTrains/yourwebpage17.msnw
Thanks again! I appreciate your help.