wiring advice / tips for layout lighting?

[nik_n_dad]

I was looking at ways to simplify (speed-up) wiring streetlights and other "accessories" on the layout, and I'm not finding any shortcuts.  I've used the "IDC" (Insulation Displacement Connector, aka "suitcase connector") for the DCC bus and the Accessory (turnout) bus, and that went very well.  However, the wires typically found on lighting accessories are a very small gauge, and the IDCs won't puncture the insulation.

 

What have others done (and I hope there's something better than "solder everything")?  

 

For DCC, I ran a 14 gauge bus.  What would you recommend for this lighting/accessory bus?

 

As always, I appreciate the help.

 

MikeA aka Dad (Nik is visiting relatives, leaving me alone with this mess)

[cteno4]

Mike,

 

With smaller wires I think you are stuck with soldering. There are a couple of little ideas that might be of use to you I've used for small gauge wiring on projects.

 

First is to make tiny plugs and sockets from pc board sockets and pins. You can get 40 pin units cheap on ebay and clip them down to the number needed. Solder your wires on and cover with a chunk of heat shrink.

 

http://www.ebay.com/itm/1-Male-Female-Black-40-Round-Pins-PCB-Single-Row-2-54mm-Pitch-Spacing-Header-/230999631790?pt=LH_DefaultDomain_0&hash=item35c8a6a7ae

 

Second is little breadboard solder boards. You can solder a bunch of sockets on these and wire them up as needed to power, add resistors or pots for LEDs, etc. wiring LEDs to little trim pots lets you fine tune how bright you want lights in different places.

 

http://www.ebay.com/itm/2PC-5CM-X-7CM-PCB-Soldering-Printed-Circuit-Board-Blank-/400509813125?pt=LH_DefaultDomain_0&hash=item5d403ec185

 

Third are little screw down terminals to screw down wires.

 

http://www.ebay.com/itm/10X-2-Pin-Plug-in-Terminal-Block-Connector-5-08mm-Pitch-/251076890677?pt=LH_DefaultDomain_0&hash=item3a75595035

 

These bits help make a nice custom modular setup that lets you pull things apart if needed easily.

 

For the smaller wiring at low amperage for LEDs the most economical wire I've found is wrapping wire. You can get a larger spool rather cheap and its pretty easy to snake around things in tight places. It's also pre tinned so strips easily.

 

http://www.ebay.com/itm/1pc-0-25mm-Wire-Wrapping-Wire-30AWG-Cable-305m-Red-/180925789423?pt=LH_DefaultDomain_0&hash=item2a200474ef

 

Cheers

 

Jeff

Edited July 8, 2013 by cteno4

[KenS]

In part, it depends what you mean by "bus". I run a lighting power bus under my layout, and then feed power to structures using copper tape.  You could call the copper tape a "bus" if you wanted (I think of it as the feeder, which connects to the bus).

 

Lighting bus or feeder, it doesn't need to be very heavy wire, because the current is likely going to be a fraction of an Amp.  I use 12V, 1.5A power supplies for my lighting (several of them, each feeding one scenic area). Even with a safety margin (I put a 1.25A fuse between the power supply and the bus and try to keep my load under 1A) these are going to power 30+ LEDs each, minimum, and more if you use a 12V supply and daisy-chain several LEDs with a smaller resistor instead of connecting each LED with its own (larger) resistor. At a 1A maximum current, voltage loss in ten feet of wire will be just half a volt with 24-gauge wire (per Wiring for DCC).

 

I'm mostly using 22ga wire for my lighting bus. Not because it needs to be that heavy, but because the heavier wire will stand up to abuse better, and mine is exposed on the underside of my layout, where I sometimes bump into it with tools when working on other wiring (I'm not the most dexterous person, particularly working above my head in a cramped space). I found 22ga a nice trade-off between ruggedness and ease of use.

 

I did some experiments with 1/4" (6mm) copper tape, and couldn't see any voltage loss to note in four feet (120 cm) of paired tape.  I also tried putting some heavy current (several amps of 12V DC) through a shorter section of 1/8" (3mm) tape, and it handled the current quite well. I wouldn't use it as a track bus, but it's fine for lighting currents.

 

As Jeff notes, for individual LEDs or small clusters of them wire-wrap wire (which is typically 30ga) is going to be fine (as long as it's not many feet in length).  The capacity is at least 120 mA, and probably more like 300 mA if there's air circulation. I mostly use 30ga wire inside structures.

 

For a single LED you can use magnet wire, which is very fine.  You should be able to get down to 36ga for a single LED even sandwiched between sheets of styrene (and higher current or smaller wire if it has air around it to cool it).