FAQ: Q&A, Discussions, eMails on LED Strips

Some information may be duplicated in other support sections and some may appear to be contradictions. Firstly, because questions are posed in different ways. Secondly, they are asked relating to differrent products and for different situations. Creating a variety of ways in which similar issues can be resolved.

Please feel free to send your projects, "tips & tricks" or suggestions for inclusion. We may include them in our Gallery section relating to LEDs or elsewhere as relevant..

Excerpts from email exchanges with our patrons.

The S12 (Old item # S-10) strip is designed for ideal illumination at 12v DC, but works over a much larger range. The power source can be via sliders or wheels in the car or a battery in the car. The LEDs are surface mount 3mm SMD's. The length of the strip is 4 inches (10cm).

Questions on Voltages in S5 Strip (for 5v):
1) Why do you limit the low end voltage to 3 volts in your specs?
2) Is it detrimental using the strip at 2.4 volts?
3) Do I need to use a current limiting resistor with 2.4 volts DC?
Please advise ASAP.

We mention the lower suggested voltages as a safe voltage limit which will still be able to provide illumination at a reasonable level. If you are okay with using less voltage, that would be fine too. The choice is yours. Lower voltage should not damage the LEDs as far as we can tell. However, you may be at the lower end of the power requirement and if the battery becomes weak or due to some other similar reason, like not enough current, the LEDs may not light up at all.

Mounting:
These are to be stuck to the inside ceiling of the passenger cars using two sided tape or any other method. How you get power into the car is different for different cars. Some make their own home made solutions on how to feed power to these strips. Since these are LEDs, they consume much less power, so you could also have batteries with a switch hidden somewhere.

We do not have specific instructions on how to install in your particular system. Our Gallery section for LEDs has some pictures of how people have done this, and you may like to get some ideas from there. Our focus is on selling lower cost generic items that are usable in many systems or situations, so we make and sell parts that are not specific to any brand.

These have been used as lighting for platforms, inside buildings, backlighting, lighting to illuminate the underside of the layout base etc.

Providing Power:
Generally cars are not wired for lighting. In case of DCC/DC, these would need what I would like to call "wheel wipers" or contacts at the wheels that will then supply power to the lighting strips inside. For wheel wipers or pickups, please visit the Accessories Section.

Some modellers have made them from scratch using a thin copper strip to contact the wheel, or sometimes from the side as well. A modelling club or a Yahoo group may be able to guide you on the design for the best for your type of system and trains. You can make these yourselves too, either by using our range of Power Pickups or by ceating one from Springy Phosphor-Bronze. Try them first using a small piece. Springy Phosphor-Bronze pieces (Off-cuts) are available in our "Accessories Section". Con-cor, we have checked before, does not make any pickup shoes or wheel wipers specifically for their cars.

In case of AC like in Märklin (3 rail), a slider under the car for positive, and negative from the wheels, is one option. Märklin sells a package/kit that has these sliders and wheel wipers/pickups. Alternately, some Märklin modellers will take the positive all the way from the locomotive to the car via current conducting couplers in each car, providing a positive feed throughout the length of the trains. In this case, the negative feed is taken from the wheel of each car to be illuminated. This eliminates the need for a slider for positive pickup from under each car which may create other issues specific to the layout. Check out our "guide" on installation.

The other option is to have a battery in the cars for power the strips. The switch can be hidden or at the bottom. As LEDs consume much less electricity, this also works.

The best way for wheel wipers, though some have made them by just attaching a strip of copper to make contact with wheels, is to ask a local modelling club to help you in installing the power feed in one car, then you could do the rest. See wheel wipers also in our Accessories Section. So all you need is to feed the power from any source either the loco or the tracks. Check with your local modelling club. Some have used a battery in the car. That also works well with individual LEDs like the SMDWW which use less voltage and the battery can last longer.

Converting an AC Märklin Axle Wiper for DC:

An exact match may not be available for many specific axle/wheel wiper installations. Axle/Wheel Wipers have been created by many modellers to suit their needs. Here is one suggestion for DC system users, based on modifying Märklin (Item 72050) axle wipers that are available off-the-shelf from any Märklin dealer and also in our Märklin Section.

Since Märklin is a 3 rail AC system, these wipers are designed to tap the axle which is not insulated, as in a DC system. So for DC usage with wheels, one simple way is to split the wiper into two and use one half to connect to each wheel. The copper strip is soft enough to provide a spring connect to the wheel without additional drag.

Here are a few simple steps for making a pair of wheel wipers for a DC system.

For installation of Pickups, exclusive to TrainAidsA, please see our Installation "guide".

Click images for their enlarged view

	A Märklin Axle Wiper in HO The lengths of the arms may need to be adjusted by cutting with a pair of scissors. The end to end length of the wiper as shown is 1.75 inches (45mm). Click image for an enlarged view.
	Märklin Axle Wiper - Flip-Side Cut neatly with a pair of scissors, to provide two halves for both wheels in DC. When fixing to the truck (bogie), space the two parts away from each other to insulate from each other. Smoothen or cut, depending on the space & convenience, the small upturned rectangular lips that have been provided, are specifically for Märklin usage. Click image for an enlarged view.
	A Märklin Axle Wiper Cut in two. The other half of the wiper would need a feed wire. For gluing metal to plastic, suggested adhesive is Loctite Super Glue - All Plastics. The pack comes with two tubes, an activator and a bonder.
	An example showing the wiper, cut with a simple pair of scissors for a specific installation.

Some other excerpts:

Polarity:
The polarity in the strip is marked. They, like all LEDs, will only work with correct polarity. For illuminating them during travel in both directions (in DC), either, feed one strip for one direction of travel and the other from the other. This way you need two strips. Please see illustration below. Then place a diode (maybe 1N4148 which we also stock in our Elektrizmos Section, in opposite directions for each of the strips. So now you would have two strips. One for each polarity.

These strips will work with any DC/DCC/AC system but with some minor flickering. Normally this is not an issue. If you do not have DC and would like to convert it to DC, we have a feed wire with built in Rectifier that is available for $1. It will convert AC to DC. The Elektrizmos Section, has more details which might help. What we normally suggest to our customers is that they buy a few strips and experiment for the best way to do it in their layout. Each layout has a unique structure. Some would like to discuss about it at the modelling club and so on.

Sizing / Cutting:
Now here is another way one customer has used. Since the strip can be cut, you can cut the strip in two. Each piece will be 2 inches. Each piece will work as if it is an independent strip with the same behavior -- The positive/negative feed points are marked in each cut part and also has solder points in each such part too. Then you alternately place the half pieces in the whole stretch (particularly if you have a passenger car). So one pair will work in one direction and the other pair in the opposite direction and it distributes the light over the whole car.

Colors:
Yellow for caboose or older era cars looks good. Use warm white for normal passenger cars and white for building interiors or back lighting the layout etc.

Waterproof:
None of these strips are waterproof, but either you could spray them with a waterproofing spray or place them in a transparent tube. Just remember to waterproof the end connectors too and in case of a tube allow some small outlet for air for temperature fluctuations.

Power/Size:
The S-5 strips are 5v but will work with 3-6v. You can add a resistor for higher voltages. We also have in our store, 12v that may be a more convenient fit. For outside use, a standard voltage adapter at any Radio Shack or other store would work. For a long length, you might look at the S-50 model (also at the same page) that is about 19+ inches each so you will have less units to interconnect. The S-50 model is the same as S-12 in its design and behavior.

Specific to customer projects:

Q:
Hi, I just got my project that I originally intended to install S12 strips in.
The situation I have is: a half-strip (3 LEDs) is not enough for the application, and the full strip (6 LEDs) is too long for the enclosure. Four LEDs at the spacing of the S12 strips would be ideal.
What would you recommend for providing four surface mount LEDs? I need surface mount because the enclosure has a long window in the side, and is only 1/4" thick inside. - Thanks.

A:
Thanks for your question. I am not clear about the application. But unfortunately the strip cannot be cut at any other position except as marked every 2 inches (5cm). Please also see our tech support for LEDs.

So here are some suggestions, based on my guess. But if you can send me a picture, I could maybe come up with a solution.

First, if the lighting is general lighting in a passenger coach or a building, you could spread some crumpled and then slightly smoothened, aluminum foil on the floor, with shiny side facing the strip light. This will distribute the light more and give a more spread out and even illumination.
Or
If you have space, you can use two strips side by side, but staggered with one strip nearer to one end and the other pushed towards the other. So the center will have twice the light. You could paint these overlapping SMD's with orange marker to dim the lights from SMDs that are strengthening the lighting, to lower their illumination.

If these strips are too thick, we also have flexible very thin strips that are sold in rolls. Please see the item FX under LEDs.

Once done with your project, you might like to send us pictures of different stages so we can add them to our Gallery section.

Best regards.

Suggestion: Get a few and try what you want to do. If it works out as you would like, get the rest. Please also read the Support section.

Good Luck in your modelling !!!

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