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titus
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So I picked up some "Model Power" grain of wheat bulbs for doing some building lighting. The package says 0.3 amps, 12-16 volts and I'm wondering where in the heck I'm going to get a power source like that. What is everyone else using?

Herb Kephart
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First- buildings don't want to be lit brightly- a soft glow, bordering on yellow is more realistic, and representative.

Second- if run at rated voltage the life of the bulbs will probably be short- perhaps as short as a few hours. If you run the bulbs at half rated voltage (6-7V) their life will be almost indefinite.

For power source, look for an old toy train transformer at a yard sale.


Herb  :old dude: 

wclm
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Titus
  Try JB Saunders in Boulder, Co. Just south of Valmont. They have new stuff and a lot of recycled electronics components. A lot of there stuff is really cheap in price.
                                                                                           Clif K

Nn3Designs
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We always have a "spare" power supply from older computers laying around. With the lower end power supplies the powering possibilities are endless. Look at the number of connectors and it has a fan for cooling. Check the power supply for the different voltage outputs and you to will see how you can power an entire layout with only one... I use them not only at work for powering a small anodizing tank but also at home when using adapters I made using "dead" battery packs for un-corded dremel tools. Just let your mind go wild on the possibilities. Also, the computer power supplies are grounded with 3 wire plugs and typically come with outputs in the 5 - 12v range. Hope this helps for future projects. :2t:

JohnB
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I simply wire them in series, two to a smallish building, and power them off the 16V AC of a power pack. Although I have a walkaround system for controlling trains, I have a couple of "legacy" power packs that I use for switch machines, building lighting, and so forth. I have structures that are 20 years old with the lighting still doing fine.

mabloodhound
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Use an old wall wart.   everyone has one of these around from and old plug in phone/CD player/etc.
Check the voltage on the item, you need something 12V or LESS!.
I used 16V bulbs in my last structure with a 12v WW.   The resulting yellow color was just what I wanted.   A 9V would probably also work fine and the bulbs would last longer.:cool:

CMmodeler
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Hi all,

I am a new member and this is my first posting.

As far a power supplies are concerned, I do not recommend wall-wart transformers.  The output voltage can go very high if lightly loaded.  I was using a 12v wall-wart to power a circuit with 17 volt tolerant IC's and blew the IC's because the voltage went over 20 volts.  I also do not recommend old train transformers.  They are a very unstable power source.

Computer power supplies work well.  They are also readily available and cheap.  One word of caution - computer power supplies are capable of high currents - fuse the outputs.  At the Greeley Freight Station Museum (http://www.gfsm.org), we use 17 or 18 computer power supplies on the 5500 sq. ft., HO scale Oregon, California & Eastern Railroad.  Each computer power supply has a line that has to be tied to ground in order to turn the supply on.  The +5v supply also needs a minimum load or the supply will shut down.  We have found that some computer power supplies (Compaq) are very sensitive to load changes.  To counter this, we put a 50 ohm 10watt resistor from +12v to ground as well as a 250uf capacitor in parallel.

As far as building lighting, the biggest problem with incandescent lighting is the heat.  A .3amp, 12volt bulb dissipates 3.6 watts of heat.  Most of our buildings are plastic and will have multiple lights per building.  I prefer LEDs.  Warm white LEDs have a yellow tint to them.  Avoid cool white LEDs - they have a blue tint.  A typical LED only requires .015amps and dissipates less than .05 watts.  10 LEDs produce less heat that one bulb even at 1/2 voltage.

I am currently working on a building lighting system that will cycle lights on and off.  It also can dim lights or blink lights.  More on that later.

Last edited on Tue May 10th, 2011 05:29 pm by CMmodeler

wclm
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Great info, thanks for the input.  When you get it up and running let us know.
                                                                               Clif K


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