Everything on model trains, model railroads, model railways, locomotives, model train layouts, scenery, wiring, DCC and more. Enjoy the world's best hobby... model railroading!

Electrical Lighting Question

Gary models HO and asks:

“If I connect a 12v light bulb (GOW or GOR) to a Railpower 1370 powerpack (with 18v of power), is that ok?  Too much voltage for that bulb?”

14 Responses to Electrical Lighting Question

  • Charlie di bellasays:

    Yes, 18 volt will be too much for the 12 volt light and will burn it out but,
    you can buy a cheap voltage regulator to adjust the amount of voltage,
    I’ve done this and it works.
    The voltage regulator will have a knob on it,
    This will be to control the amount of voltage but will also control the light as it works as a dimmer.
    Hope this is of some help to you, cheers.

    • Garysays:

      Hi Charlie: Thanks for your comments. I’m also considering another bulb (from Model Power) which is described as a “12-16v” bulb. I’ve used this type of bulb before on my layout and haven’t had any of them burn out. Gary

  • Guillermo Patterson from Patagonia Argentinasays:

    Hi Gary.
    What means light bulb GOW or GOR ?
    My mather lenguage is Spanish, and I don’t understand what GOW or GOR means.
    Thanks for your help.

    • Garysays:

      Hi Guillermo: GOW is Grain of Wheat. GOR is Grain of Rice. The grain of wheat bulb is slightly larger than the grain of rice bulb. Gary

  • Newman Atkinsonsays:

    Gary, If you take a HO DC transformer, the voltage for track power is 0 to 12 volts. With that you have an adjustment to adjust the intensity of the lights. Now on some power packs they include 2 terminals for fixed 12 volt DC which is always good way to go too. You would not be connected to your regular transformer but that is ok too. I use a 12volt varible HO Train transformer to power a computer fan that I use to pressurize my smoke from a pond mister and in a contained system it forces the fog out 2 smoke stacks on a power plant. Because it is just water it is safe to breath unlike the smoke oil they use in your steam engines. That and I can run all day on the pond mister and not have to refill where if using a oil heater I would be refilling it all the time. using the track reostate I can adjust how fast I can run the computer fan. The same will work for your lights.
    from Newman Atkinson

    • Garsays:

      Hi Newman. The smoke stack steamer sounds like something I would like to add to my layout. I currently have several door bell buttons that light up things on my layout. My grandsons love pushing the buttons. My last addition was using an old CD player turntable parts to make a road roller move back and forth. If you can, please email me the components you used for the smoke stack steamer. This would be a tremendous addition to my push button devices.

      Thanks very much.

  • Nick Markssays:

    Gary, listen to what the first reply by Charlie said. If your transformer is fixed at 18V, that’s way too much for a 12V bulb. Some extra voltage is ok but not 50%.

    • Garysays:

      Thanks, Nick. I figured it was too much voltage but wanted to toss the question out there anyway. I’m not very good at the electrical aspects of our hobby.

  • Dan Potgietersays:

    Gow bulbs draws about 60ma on 12v. To restrict the current on 18v put a resistor of about 220 ohm by half watt in series with the 18 volt supply. You have to experiment a little because all gow bulbs are not the same.

  • John Byerssays:

    If you put 2 bulbs in series (not parallel) using an 18v power source it is the same as feeding them 9 volts, which will make them a little dimmer than 12v but they will last much much longer. The only drawback is if 1 burns out, the other won’t light until you replace the burned out one. The 2nd bulb does not have to be next to the 1st, it could be in another model building, or next to the powerpack. But it has to be in series. One could also use a resistor, but I’m not sure how many ohms.

    Another possibility, many power supplies put out a higher voltage under no load than under load. If you have a voltmeter, check the output voltage of your powerpack with the number of light bulbs you are planning to use hooked up. It may have dropped to 12. You may still want to lower the voltage, as running a bulb at less than its rated voltage lengthens its life tremendously, although reduces the light output.

    • Garysays:

      Hi John: Thanks for all your info. I didn’t realize the voltage is reduced by the number of bulbs in a series. Actually, what I’m doing is this: I have a tennis court on my HO layout which I’m planning to light. I’m planning to use 8 Model Power 12-16v GOW bulbs (2 bulbs on each of 4 light towers) connected to a Railpower 1300 power pack. The specs for the 1300 say it has 19v of AC output for accessories. It sounds like, after reading your comments, that instead of being concerned about too much voltage, that I might wind up with a dimly-lit tennis court! Thanks again.

      • John Byerssays:

        You could hook the 2 bulbs on each tower in series, but have each tower in parallel with each other. That would give each bulb 9 volts. Hooking all 8 in series would give each bulb just over 2 volts, which would be waaaaay too dim.

        For anyone who doesn’t know what parallel & series means: Parallel means each device (which can include a grouping of other devices) has 1 wire going to the positive and 1 wire going to the negative terminals. Series means 1 wire from 1 device goes to a wire from the next device, and so on. The other wire from the 1st and last devices going to the + and – terminals. They are 1 after the other, like a chain. In the situation above, each tower would have a wire coming from the power supply, going to 1 bulb. The other wire on that bulb would go to 1 wire of the other bulb. The other wire of the 2nd bulb goes to the other terminal on the power supply. That is series. Then, the same thing is done with each of the other 3 light towers, so you end up with 4 pairs of wires (1 pair from each tower) going to the power supply. The towers are in parallel.

        If you put enough devices in parallel you will eventually exceed the amperage capacity of the power supply (just like if you plug several space heaters into 1 circuit of your home the house wiring would overheat and possibly burn down your house if you didn’t have a fuse or circuit breaker protecting your wiring) and it will either damage the power supply, or it will pop a fuse or circuit breaker in the power supply. I don’t think 8 GOW bulbs will draw too much, but I don’t know how many amps your power pack is rated for. Looking on the internet, it seems GOW bulbs draw a little under 1/11 amp each, so you could safely run about 11 from a 1 amp power supply. An ammeter(rated for the voltage & amperage you are measuring) in series with a device will tell you how many amps it is drawing.

        • Garysays:

          That’s helpful info. thanks, john

  • roy e carslakesays:

    Have you thought of using LEDs 8 in series could be run on 12volts

Leave a Reply

Your email address will not be published. Required fields are marked *

Add a photo or image related to your comment (JPEG only)

Everything DCC

Free Catalog

Use Tiny Railroad Micro Controllers

A micro controller is basically a small programmable computer device to help the model railroader “make things operate.” It is clever way to realistically replicate the movements, actions and functions you are likely to see on a full size railroad.


Submit Your Model Railroading Questions!

Before you submit your model railroading question please add some feedback, answers or comments to other postings on this model train blog. What goes around comes around... so if you can help others in the hobby, someone else may help you.

Important - Please add plenty of supporting details to any question you submit (eg. scale, solutions you have already tried etc.) , as the clearest and best questions usually get the best answers. Also, please check your spelling and punctuation as all questions need to be approved by the blog moderator prior to publication. Approved questions are normally published within a week (if not sooner).

Submit your model train questions here.

Watch These Club Videos

Club members access helpful new resources each month: diagrams, video tutorials, articles, track plans and more. Watch the tour videos here.



N Scale Track Plans

Watch Video

Model Train Help Ebook

Scenery Techniques Explained

Bringing Your Railroad To Life!

Scenery & Layout Ideas

Share With Friends


Submit Your Article

Would you like to write an article and have it published?

Preference will be given to articles that help others progress in the hobby, maybe suggesting an idea for their layout, a quick tip or two... or perhaps a little bit of good advice based on your model railroading experiences.

We are all in this hobby together, so the more we can do to share ideas and help each other, the better.

Submit Your Article Here

It’s YOUR Railroad!

Your rolling stock and locomotives might actually be the center of attention on your layout, but the scenic features that surround and envelop your layout is what's likely to make your train setup stand proud of the rest. Your selection of scenery and structures will add an element of customization that will make your railroad truly unique.

Scenery, structures, and fine detailing is a fundamental aspect of any good model railroad, particularly if it is intended to replicate a true-to-life railroading scene. How realistic or authentic you make your railroad is entirely up to you... and you alone.

Some enthusiasts like to replicate every tiny detail so as to accurately depict, in every aspect, a miniaturized version of a real life scene.

Others in this hobby adopt a more "free-style" approach and choose to mix and match accessories and features they personally prefer. Even though the purist will possibly be unimpressed with unrealistic or out of context elements, it is YOUR railroad layout so you can make it anything you personally want!

Model Railroading Blog Archive

Reader Poll

Sorry, there are no polls available at the moment.