Not quite ready yet but it won’t be too long until I will be ready to install structures on my layout. I want to be able to add lighting to the sructures as well as various other stuff (street lights, oil pumps, etc) as I go. I am looking for a strategy that would allow me to put suitable wiring and power source under my layout now for power and then connect stuff to it as I go. I have seen the various commercial products that offer a plug-n-go strategy but I think that would get too expensive in the long run.
I am assuming that I can install a power wire under my layout now then hook lights to it later. I am looking for suggestions on how to best do this. My current thinking (right or wrong) is as follows:
I can put a single power bus that runs the length of my layout. That would be about 45 ft. What power level should I plan for? 12DC? Lower? Would it be best to break this down into shorter segments with multiple power supplies?
I would prefer to tap into the power buss via a terminal strip. I want easy connections…no solder.
I want LED lights to keep everything cooler. Don’t want hot spots in the structures. I know I will probably need resistors for the LED’s. What type of LED should I be looking for? I know this will probably impact the selection of the power levels.
Some items may want 12VDC while others want something less. Can I run a 12VDC buss and step the voltage down as needed for items that want something less? Example: I have an oil pump that can run on 0-12VDC where the voltage determines the speed.
I would prefer a suggestion that accomodates and address all these issue in a single design approach. Telling me I need to use 9V without linking it to the other factors leaves me hanging.
One wall wart power supply from walmart. Run wires to terminal strips.
A package of 100 LEDs with resistors from the internet/Ebay (my son-in-law did the ordering). Wire one resistor to each LED, then to nearby terminal strip, and drill hole up and that’s it.
I’ll answer your questions first, and then I will make a few additional suggestions.
You can use a single 12 volt power supply (provided that the amperage demand doesn’t exceed its’ capacity of course), but if you are going to run a lot of lights you will need fairly heavy gauge bus wires to avoid line loss over the 45’ length. I would suggest 14 ga. min. To determine the draw, you should calculate about .09 ma (milliamps) per LED although the draw will be lower if you use higher value resistors. Read Mel’s response below for another option. His method avoids the heavy bus wires.
12 volts is easy to work with. There are other ways to do it but most people are using 12 volt power supplies.
That will work, sort of. You can buy LEDs with the resistors already attached, but the leads are usually less than 12" long. In order to install several LEDs in a single structure you will have to have terminal strips within the reach of each of the LED leads. If it is a larger structure that could get pretty complex really quick. You would be much further ahead if you can learn to solder so that you can create a wiring system just like what your home uses. It’s not hard.
Terminal strips could still be used under the layout so you don’t have to run multiple wires back to the power supply like Mel does. Both methods will work.
[quote user=“PED”]
3) I want LED lights to keep everything cooler. Don’t want hot spots in the structures. I know I will probably need resistors for the LED’s
I worked my entire career in radio communications so my way of wiring is similar to the Ma Bell way. I have home runs back to my control panel from every structure except street lighting. My street lights are paralleled.
Most of my lighting is incandescent (GOW) not LED, to me incandescent lighting operating at reduced voltage (12 volt bulbs operating at 8½ volts) is more realistic. Using 70% reduced voltage on the bulbs also greatly increases their life, I’ve only lost two bulbs out of well over 200 bulbs in 28 years.
Because each structure has its own wire the current is very low, I use #24 telephone frame wire for my lighting. The cost is right, about $18 per 1000 foot.
By using home runs I can easily either parallel the lights on a single switch or with individual switches at my control panel.
For my advanced lighting using Arduino Lighting controllers (20 individual lights per structure) I use flat ribbon cable.
Thats the kind of info I am looking for. I guess I need to add…
I can solder very well. The issue is that at my age, I don’t like to climb under my layout to do a lot of soldering. Topside is OK.
I know the availability of premade LED/resistor very well. I have a bunch already but they are all red and green so it looks like I would need to shop for some suitable warm white ones.
I think a good approach might be to run a 12V feeder wire from the buss up to each structure then make all the solder connections inside the structure for the short wires to the LED/resistor. That way, I can prewire a structure and only have a single feeder wire down to the main buss.
I don’t mind having mutiple power supplies if necessary but I have a 12VDC power supply sitting idle that can power more lights/devices than I would ever put on my layout.
OK, that fills in the picture a lot better. I apologize for assuming that you didn’t know how to solder. My bad![D)]
In your situation I would suggest doing what you originally planned. Install a bus lighting system under the layout with terminal strips placed appropriately. Then do all your lighting and soldering at the workbench. Instead of coming up from under the layout to attach the feeders, install the feeders in the structures and then just drop them through the layout and hook them up to your terminal strips. No soldering under the layout. If you want the structures to be easily removable, you could install plug connectors in the feeder wires so you can lift up the structure and just unplug the feeders. No need to go under the layout to disconnect things at all. That can be really handy when you want to remove a structure to do more work on it.
i use 3mm golden white top hat LED’s for lighting . i use a single power supply divied into sections controlled by small toggle swicthes , not all lights have the same restistor allowing varying light levels, also have the street lights on a curcuit that turns them on at low light levels.
Thanks all. I think my strategy will be to place some terminal strips at strategic locations under my layout then daisy chain them together along a 12VDC buss powered by a 15 amp 12VDC power supply I have.
Then for each structure, I can build it from scratch to include lights connected to a single 12VDC power wire. Each LED/resister combo will be sized according to their usage and then connected to the single 12VDC power wire for that structure. The power wire will have a small connector (I already have a bunch from a previous project) that will allow me to plug it to a 12VDC feeder wire that goes down thru the layout and connects to a terminal strip on the 12VDC buss under my layout.
This will allow me to have a single 12VDC buss with a 12VDC feeder wire to the top side structures such that I can plug/unplug the structure as needed. This will allow me to build all my structures with appropriate electrical stuff at my work bench then put it in place and plug it into the power buss on the layout.
I don’t have any control panels like Mel noted but I will come up with a way to turn stuff on/off. I think I may be able to use some old DCC loco decoders to control some stuff such as oil pumps so I can turn them on/off and vary the operating speed (pump head speed) from my throttles. Should be easy to do by wiring them to the rail (aka wheel pick up) and controlling the DC devices (aka loco motor) just like a loco.
I will probably build a mock up on my bench and test out the details before I climb under my layout [:D]
My only concern is the 15 amp 12 v power supply. I think it might be wise to install a circuit breaker to protect everything on the bus if there isn’t already one built into the power supply. 15 amps is a lot.
if you have a foam base, you could cut a slit in the foam to bury the (thin) wires to the structure and bring them to the front of the layout where they can more easily connected to a bus.
I’d suggest getting a 25-ohm rheostat to hook up between your 12V DC source and the lights. As someone noted, lights generally look a lot more realistic if running at less than full power.
I do plan on something like that but I failed to mention it earlier. Not just to control lights. I have some Walthers oil pumps than need some lower voltages to run at a good speed. Their max is 12V but even at 9V, they run faster than I want. I had been considering an old DCC decoder to control them but a rheostat (plus an on/off switch) would probably work better (and cheaper)
My suggestion is a single power bus - of the highest voltage you need. You cn get these cheap buck converter modules from eBay or Amazon that take up to a 30V input and produce something less - they are adjustable so if you have some things that need 5V, you can still have a 14V bus and tap off 5 volts. Or 9 volts. Or 12 volts. Each one is good to 2 amps (but not really - they need a heat sink for that, that’s just the max of the chip used), but a 1 amp or less load on each one is fine. They are a lot more efficient than a common linear regulator. Only a couple bucks each in quantity, I’ve picked up 2 batches from different sellers and the one style is definitely better made - easy to tell by the direction which the input and output capacitors are arranged on the boards - but they all work fine. One of the ones I consider inferior had a bad solder joint on the input capacitor but so fat the other batch all checks out.
So run power for whatever voltage the majority of things needs, then reduce it at the take off points for devices that need lower voltage.
I’ll second Randy, the DC to DC convertors work great. I use the higher current versions and so far no problems. I have one set to 1.35 volts for my 1mm 1½ volt micro bulbs for my vehicle headlights, one set for 5 volts to power my Arduinos and a third set to 8.5 volts for the 12 GOW lighting. The reduced voltage (70%) looks more realistic and the bulb life is extended to years of continuous duty.
I had to take a look at these buck converters to see what they were. I probably will use them, but I had to laugh at the picture. I could be looking at a Chinese coin the size of a silver dollar or smaller than a dime
Note the two large capacitors are installed with the leads to the top and bottom of the board.
The ones I got from eBay had the capacitors arranged so that one lead was right at the edge of the board - this is where I had a bad one, the board was cut off a bit too close to the capacitor lead. For small boards liek this, they actually make them on larger sheets and then cut them apart into individual boards - in this case it would seem they do it AFTER the pick and place machine has added the compnents and they are soldered. They all worked - even the bad one, but it had a huge amount of ripple in the output which seemed to vary if I pressed on the board. Lo and behold, a careful inspection revealed the loose solder joint. I have that one marked and I doubt it will ever get shoved up under the layout, but it works fine for bench testing.
They’re all build from the basic data sheet circuit for the chip used, the LM2596. They are small, less than 2" long, but not as small as that micro size one pictured above. I suspect that design won’t be as clean on the output since it uses a 100mH coil instead of a 470mH for size reasons (the single largest part on the board - coils are like speakers, you can’t get a high value in a miniscule space, the laws of physics get in the way).
The other difference with the ebay ones I don’t like is that in addition to the one capacitor lead being too close to the edge of the board, so it the trace leading to it - one of the input lines and one of the output lines. On the b
