LED Light Frequently Asked Questions

Have a question about LEDs? Our LED lights FAQ page has the resources to help you solve your issues quickly and effectively. These LED FAQs cover a variety of questions like "Can these work outdoors?", "Can I fit my LED into a tight space?" and much more. Find helpful solutions to your questions and problems with the help of the LED FAQ page from Evan Designs!

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What’s the difference between small, tiny and mini LED lights?

Small, tiny and mini LEDs all offer the same bright glow to light up your space, but they vastly differ in size.

Our pico and Z tiny LED has the thickness of a credit card, and pico is only 1mm wide. Z LED is also thin and only 0.6mm wide. Our mini LEDs include the chip nano. Our small LEDs are 1.8, 3mm, 5mm and Mega. They can be used with larger model trains, O scale or G scale.

Surface mount LEDs from smallest to largest are Z, Pico, Nano, Chip, Mega.  Surface mount or chip LEDs are flat and ideal for all Model Train Scales including O, S, HO, N, and G, or dioramas and building lights up to 1/4 scale.

Bulb style LEDs from smallest to largest are 1.8mm, 3mm, 5mm.

Pico, Nano, Chip, 5mm, 3mm or 1.8mm LED lights?

What we are referring to when we mention size is the measurement across the width of the bulb.

If you are unsure of the size you need, you can try measuring the opening that you plan to fit the bulb into.

  • Chip, Nano, Pico and Z LEDs are great for use in action figures, small model cars, planes, and sci fi creations such as space ships.
  • 3mm LEDs are great for locomotive headlights, warning beacon lights, train running lights and ditch lights. They can also be used for 1:18 and 1:43 die cast modifications and most RC uses, as well as diorama street lighting. However, in terms of brightness, there isn't too much of a difference between the 3mm and 5mm LEDs.
  • 1.8mm LEDs are used in 1:160 and 1:144 scale models. These bulbs are excellent for models where there is not much space to fit a bulb. And, these LEDs are still extremely bright at 400 mcd.
  • 5mm and Mega are the largest sized light we offer. We suggest using them for building lighting, passenger car lighting or larger scale train running lights. If the bulb shouldn’t be seen, Mega is a good choice since it throws the light around more than the bulb style. We often use 5mm bulbs with our Fire LED Kit and our Welding LED Kit when they are staged inside of a building.

Why Switch to LEDs?

If you're considering making a switch to LEDs, here are four great benefits: 

  • LED lights don't heat up like an incandescent light. Therefore, when using an LED, you won't melt the roof of your building or the housing of your train, diorama, water tower or emergency vehicle.
  • LEDs are extremely long-lasting, with a run-time of 100,000 hours or 10 years. An incandescent bulb, on the other hand, will last 750 hours or so. Plus, we guarantee our lights for two full years with a free replacement in the event of malfunction.
  • Although they're small, LEDs are very bright. Our Mega cool white has 4,700mcd.
  • LED’s are shock-resistant and durable. The bulb style light emitting diode is encased in solid epoxy which can be sanded if desired.

Do I need AC LEDs or DC LEDs?

We recommend using universal LEDs under the following conditions:
  • If you are running your LEDs directly on your railroad track power
  • Hooking them to the DC accessory outlet on your train's power pack
  • Running them to your dolls' house transformer power supply or other existing power supply
DC trains switch polarity (whenever you back up) and train transformers have "spikes" or "ripples" as well as surges and interruptions.
There is nothing wrong with this uneven power for most devices, but for LEDs this spells trouble. To protect the lights from this, we have added a full wave bridge rectifier and a filtering capacitor along with the resistor. Even if you have a DC train and you only run your train at 12 volts or less with N Scale Kato power supplies, we still recommend getting universal LEDs.

Running your LEDs on a 9V Battery or Regulated 12V DC wall adapter, get our DC LEDs. These LEDs all come with the correct resistor and connector wire pre-assembled, so they're set to go.
How do I wire the Universal LEDs parallel? Fed by how much power?
Wire lights in parallel. Gather 1 wire form each LED and bring to + then gather the remaining 1 wire from each LED bring to ground. That's all that is needed! Each LED draws 20 milliamps so 20mA x say 5 LEDs is still only 100 milliamps. The lights already have a resistor rated for 7-19 volt operation so no worries on voltage input. The accessory side or track side of your transformer will work just fine.
"DC and Universal, what's the difference and advantage / disadvantage of each?"
Universal LEDs have more protection built in to compensate for AC or DCC which switches polarity

and protection from non-regulated DC power supplies which can look like this and often deliver more than the listed amount of power. So for example a listed 12V non-regulated adapter can put out as much as 17 volts of power due to the low draw of LEDs. The proprietary Evan Designs circuit covered by shrink tube that you can see in the following picture

has a full wave bridge rectifier for reverse polarity protection and a filtering capacitor to remove voltage spikes/dips. Then, a resistor is added just as in the DC bulbs. Universal LEDs are built for unstable power supplies, and ensure that the power making it to the LED is "smooth" DC power.

If you use a high-quality regulated 12V DC adapter, you will not need any extra protection since you will have "smooth" regulated DC power that the LEDs require. DC LEDs are less costly since they do not have the bridge rectifier and capacitor. DC lights will also run just as long as universal LEDs, provided they have the correct power supply.

If you use an existing train transformer for some or all of your lights, you will need to use universal LEDs.
”Can I get more light spread?”
The bulb style LEDs we sell are “wide angle” lights, and most have an average of 35 degrees of light spread. If you find that you need more spread, you can sand off the rounded top of the LED without harming the diode. This will increase your light spread to 80 degrees or more. Alternatively, consider our surface mount Z, Pico, Nano, Chip and Mega lights. These bulbs have a much wider viewing angle and are flat, so they can be placed on the ceiling to light a whole room.
”Can I fit my LED into a tight space?”
Yes, LEDs can be bent up to 90 degrees to perpendicular at the stalk and still light! While you can bend the bulb style LEDs, you may want to consider the flat LEDs, as they are easier to hide and are used in many modern electronic devices.
"How do I add or change LEDs in decoder boards?
Refer to the manual that comes with your decoder board. Most positions for added lights are 14 volt, though there are some positions that are 3 volt. Often, within parts made by one company -- and even within a single decoder board -- there are usually at least those two voltages present.
”How much power do these lights draw?”
Most LEDs only draw 20 milliamps of power, which is less than 1/3 of an incandescent at 65 milliamps of power. You can connect quite a few LEDs to your power source without dropping any power to your model trains.
DC Flashing LEDs, using a single 9 volt battery, how many could I install in a Project like a Police Car?
You can put as many DC flashing LED lights in your project as you need to get a great effect.

We have installed lights in many types of police cars and firetrucks. They're much more real when lit up, and the LEDs are super bright! For modern emergency vehicles, we like to use the DC fast flashers in the light bar and on the vehicle. Headlights sometimes look better with normal speed flashers or our wig-wag circuit.

For the older era police and fire vehicles, we use a normal speed red flasher in the dome light and either solid or flashing headlights and tail lights. If you're placing your car near your model trains and connecting to track power, look into using our Universal Flashers

Our 1000ma 12V adapter has the ability to run 50+ lights with ease. And, when we don't want to use a wall adapter, we simply use a 9V battery. According to Duracell, their alkaline 9 volt batteries are rated 580 milliamp hours.

In our tests with Duracell, we connected 3 flashers to a 9V, and the lights were nice and bright for 40 hours. We used our Strap/Switch Combos that make it really easy. The strap has an end that snaps onto the terminals of any 9V battery and a long tail of red and black wire that can be connected to the lights.

”Can these work outdoors?”
Yes. These LED’s are the same ones you see around car license plates and in flashlights. The Light Emitting Diode in an LED is completely encased in tough epoxy.
”Can I wire these to my track power?”
Yes, you can. Our Bridge Rectified Universal LEDs are specifically designed to run on any track power. These lights are "plug and play" pre-assembled. You need to do nothing more to these lights! The bridge rectifier means "constant on" lighting with DC, AC, or DCC track power. Refer to the diagram that came with your locomotive to check where to attach the leads for your particular loco. To light a passenger car, you will need to run the wire down to the track through the "truck". Check back soon for a short article on attaching an LED to power on your rolling stock. In general, the red wire goes to the positive the black wire goes to the negative.
”Why Do I need Pre-Assembled DC LEDs ?”
An LED bulb can only handle 2 - 3.5 volts of power, depending on the color of the LED. White can handle more voltage than red, for example. If you were to connect an LED bulb straight to a 12 Volt DC power source without a resistor, you would see a very brief bright flash as the LED burns out. We have soldered a color-specific resistor to the LED so that it will work with your 9 or 12 volt DC power source without harming the LED. Our 12 Volt DC LED's can run on anywhere from 6 to 14 Volts and are fully guaranteed to work, with a 2 year Replacement Guarantee, if you run the LED at the correct power.
”Why do I need Universal or AC LEDs ?”
An LED can only handle 2-3.5 volts of DC power. AC Trains, Digital Command Control Trains and DC trains have power supplies putting out 7-25 volts. We have added a full wave bridge rectifier and a larger ohm value resistor to these LEDs to protect the LED from both the higher forward voltage, and the switching polarity of AC and DCC trains. The great thing about the Bridge Rectifier is that these lights stay lit even when the trains are run in reverse!
”You say AC or DC, which is preferred?”
The LED’s are made to run on DC power. If you are running AC, DCC or plan to run DC in reverse (backing up) we recommend our 7-19 Volt Universal LEDs.
”How many LED's can I wire in parallel?”
The LED’s we sell draw 20 milliamps of power. So check your power source. If you have a wall plug power source with 1Amp of power you can run (1000 / 20) or 50 lights in parallel!
”Can I mix colors, sizes, flashing and solid in the same model?”
Yes! You can mix any color light and size of light (and solid and flashing) in the same application. see a great example of this:

”What Can I used LEDs in?”
You can use LEDs in Locomotives, passenger cars, buildings, emergency vehicles, model boats, model airplanes, model dioramas, RC Boats, Planes, Helicopters, Trucks. The durability, low heat and extremely long life of LEDs make them by far the best choice for every type of modeler! check out our gallery to see some great photos that our customers have sent us!
One thing about flashers especially that we should emphasize: They need to stay flashing! And the biggest thing is flashers that stop and go to steady after some period of time on power. We don't like to dwell on how much time it has taken to get the ones we carry now. Let's just say a lot of trial and error, and a lot of pitched lots of LEDs. We have test boards everywhere with LEDs connected to various power supplies. Some of them for years now. There are 2 things that go into making LEDs we can guarantee for at least 2 years of use 1)high quality chips 2) perfect soldering technique. We trained the factory we use now ourselves. And financed their purchase of some very high quality Taiwanese ESD irons, sooner than have them use the irons they already had available. Using other LEDs is kind of hit or miss. It's worth it we feel, to pay a little extra for LEDs that don't need to be removed down the road when they fail.

Still have questions we did not answer? Contact us! Or call 303.410.1118 We will be happy to answer your questions!
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