power for street and building lights

[RA1]

Any thoughts on how to best wire building lights, street lights, and similar accessories? Since I want to be able to control these lights independent of operating my DCC locomotives, I need a separate electrical distribution system, with an independent on and off switch, but can I run off the DCC transformer? Do I need a separate transformer?

[richg1998]

 Some years ago our club used an old power pack. For constant lights, we used the 14 vac output and for variable lighting we used the DC control to reduce lighting for night time viewing.

If we added LED's, we used the AC buss with a diode to provide DC and a resistor to reduce the current to about 15ma DC.

We used the KISS principle. Out turnout machines are PFM slow motion and the turtle machines.

Rich

[brakeman321]

hi

  look for an old computor PSU 200 or 250 watt their out dated and seldom used any more.

Stop by just about any computor shop they'll usualy give you one used to get rid of'em.

 t

hey work out to 20 to 30 amps@3volt 15 to 25 amps@5volt and 10 to 20 amps@12volts

you'll have to jump the switching circut and add resistor on the 5volt line they are wonderful

as power supplies low v for mirco bulbs the 5v is useful you hook 4 1 1/2 volt bulbs in a series

witch gives them about 1 1/4 volts per bulb then the 12 volt can run any thing

you can buy a new 250 watt for about 19.00

                            brakeman321

[tstage]

RA,

Obviously, if you want independent control, you'll need to wire your lighting "in parallel" (vs. "in series").  You can use either slide or toggles (SPST) switches to accomplish this.

Also, depending on the number of lights you are talking about using on your layout and their accumulative current draw, as well as the overall (total) amperage of your DCC system, you may want to consider using a separate transformer or power pack.  Otherwise, you might end up drawing off crucial power that could be used to power your locomotives.

Then there's a choice of incandescents or LEDs.  I really like LEDs for headlights.  However, I very much prefer using incandescents for exterior/interior lighting because they are:

• Warmer - LEDs (like florescence) tend to be stark and wash out scenes
  
• Adjustable - Along with warmth, you have a wide range of intensity with incandescent lighting from barely glowing to bright.  Although LEDs can be adjusted slightly, they are generally "on" or "off".
  
• Diffuse - LEDs are very directional in their beam.  (Hence why they work so well as headlights.)  Incandescents emit a more uniform "glow"
  

Your other choice is whether to power your lighting with AC or DC.  This can be done from either a wall transformer or a power pack.  I prefer the DC terminal of a power pack because:

• It allows the ability to adjust the intensity of your lighting (See "Adjustable" above)
• Increases the life of your bulbs so that they last longer.
  

For adjustable power sources, I use MRC Railpower 1370 power packs because they are solid performers and generally inexpensive.  I just use the dial to operate my lighting at about 50-55% maximum output of the bulb.  Since power packs are generally 12V+, it's much easier to do this with a 12V or higher bulb (vs. a 1.5V).

A few other things worth noting:

• For exterior lighting: Try to find bulbs that strike a nice balance between realism and bulb life.  For HO, 1.2mm - 1.5V are very prototypical in size but have a maximum bulb life of 1000 hrs.  1.7mm - 12V are slightly larger in size but overall bulb life is increased to ~5000(?) hrs.
  

• For interior lighting: Unless the actual interior lighting bulb is going to be visible though a window, go with the largest bulb life you can find.

Again, "dialing down" the output voltage will increase bulb life dramatically, as well as give your layout a warmer appearance.

If you end up using a wall transformer or other power source instead of an adjustable power pack, I guess a resistor(s) could be used to lower the voltage.  For me, though, the knob on the power pack just makes it easier.  It's also always a good idea to label your power pack so that no one inadvertently turns it up; not knowing that it's associated with powering the lights.

Lastly, RA, if you are looking for inexpensive alternatives to lighting your layout, here's a link to a "how-to" tutorial I've written for scratch-building exterior light poles. This can be adapted to both interior and exterior lighting.  Also, for convenience, you can copy, paste, and size the diagram and instruction sheets into a Word.doc.  For the cost of materials: Each light pole came out to be about ~$1.75/ea. for a single; $3.25/ea. for a double.

Anyhow, hope that helps...

Tom

[tomikawaTT]

My preference for powering 'scenery' lighting is to go with a motley collection of wall warts, toy train power supplies (Bachmann, Life-Like etc...) and a couple of 'purpose-bought' filament transformers for larger/ more complex lighting systems.  On the 120v side, they plug into a dedicated layout power circuit via circuit breaker equipped power strips, one per town.  On the low voltage side, each town has several parallel circuits, each powered through its own set of toggle switches so all the lights don't go out at the same time each night.

Where the lamps aren't directly visible, I use series strings of 2.5 volt miniature Christmas lamps, so sized that each lamp only gets about 60-80% of full voltage.  60% (1.5v) gives a nice yellowish 'residential lighting' glow, while 80% (2.0v) yields a whiter 'industrial/commercial' light for workshops and retail sales buildings.  (Restaurants look better with the softer, yellower light.)  My lighting circuits are AC, so LEDs are non-starters.  I use series strings rather than resistors because I bought several cases of Christmas 'icicle lights' for a few cents a lamp on after-Christmas clearance.  The aditional lamps (sockets included!) cost less than appropriate resistors, and I have thousands of them.

My take is that having a number of smaller power supplies avoids the problem of a regional blackout if a single big power supply fails.  Also, those wall warts (from defunct low-voltage devices ranging from rechargeable calculators to rechargeable hand tools) and toy 'transformers' (yard sale queens, cost a buck or so apiece) are extremely inexpensive.  I own enough that if one packs it in I can replace it in minutes from my stock of junk serviceable spares.

Chuck (Modeling Central Japan in September, 1964)

[jeffrey-wimberly]

 I use an old AT typa computer power supply. This gives me all the power I need in two voltages, 5 volts and 12 volts.

[Doc in CT]

 For LEDs or bulbs you should consider a separate bus just like you used for the DCC side with a separate power supply.  (If you don't want to go the PC power supply route - there are issues) I found 12v 4-5amp "monitor" power supplies on e-bay for around $12.

LED or bulb, keep track of the amperage, LEDs may be bright, but they do require current.

Alan

[MisterBeasley]

For my lighting, I decided to standardize on 16-volt bulbs.  I run these all at 12 volts, which give me a warm glow, doesn't overpower the scene with bright lights, and keeps the bulbs running for a long time.  For interiors, that also makes the bulbs run cooler.

The Walthers Cornerstone street lights are 16-volt, which is how I got started at that voltage.  I just keep a stock of 16-volt Miniatronics grain-of-wheat bulbs and add them to structures as I build them.

[Doc in CT]

 One can find LED based street lights on e-Bay.  Inexpensive (under $1.50 ea) but need clean up and painting, including the light/hood cover as the LED shows through (black paint fixed that).

[mobilman44]

Hi!

I think its an excellent idea to use a separate power pack for lights & accessories.  With my last layout (HO-1993-2008), I used an MRC Controlmaster 5 to power turnout solenoids, lights, etc. on this DC layout (I had two MRC Controlmaster 20s for loco power).

For my now under construction HO DCC layout, I am using the same Controlmaster 5 to power stuff other than the trains.  So far, everything works just great. 

Mobilman44

[Allegheny2-6-6-6]

 As a general rule in DCC you do not want anything hooked to the DCC buss other then track feeders and stationary decoders if your using them. Everything else that requires power on your layout should have a separate power supply. Wall-warts are a good source of inexpensive power for things such as structure lighting street lights, lighted signs etc. I to like to run a separate pair of buss wires around the layout and at specific spots I run feeders to a terminal block and from there go to my structures etc. I have heard of problems resulting in fires from using computer power supply's but can't confirm that to be true or not as I've got zero experience  using them on a layout but the prospect does sound interesting I will admit. What ever power supply you decide to use you should always plug it into either a GFCI outlet or a power strip with a circuit breaker. The last thing you want to do is burn your house down by a defective power supply.