Wiring for lighting etc

[rhubarb]

Now the winter is setting in i've decided to get on with my son's DC layout (which has been dorment since spring!!)

 

Could anyone give advice on power supply for 6v or 12v lighting. These would be for yard,street and platform lighting. What i'd like to do is have one incoming supply then spur off (via switch's) from an electrical enclosure box so lights can be switched on/off individually.

 

As yet i have not found any suitable power source (ie 240v to 6v or 12v supply with multiple outlets would be good!)

Anybody done similiar on their layouts.If i have to i my switch to DCC although all stock is old DC.

 

Thanks.

[96701]

I use an unregulated 12V dc power supply such as this http://www.maplin.co.uk/images/full/gs74r.jpg . I bought the appropriate socket to match one of the plugs, mounted it on the side of the baseboard and soldered bus wires to the connections on the back with droppers to switches also mounted on the side of the baseboard.

[Edinburgh Junction]

Hi Rhubarb!

 

What you want, is this, which is a mains transformer, changing the mains power supply into 12v DC, which is what all lights for your layout will run off. The positve will go to an on-off toggle switch, which will go to the transformer. the negative will go to straight from the lights to the transformer.

 

Hope it helps.

[Penlan]

I use an old controller, nothing sophisticated, something out of a train set, and then I can control the brightness of the the lighting.

 

12v bulbs, don't always need a 12 volt supply!

 

Penlan

 

Edit - I suppose I should add, as the max voltage given out by the basic train set controllers can be up to 16v, then using a simple multimeter, I find the 12v point the knob turns round to and make a 'stop' at that place.

[iL Dottore]

You can also get linear power adapters with variable outputs that take mains voltage and step it down to one of a number of low voltages (mine goes from 3v to 12v) in a number of steps. Here is a link to one such (http://www.made-in-china.com/showroom/ninghaiyingjiao/product-detailrTYmFKQMRJWx/China-500mA-Linear-Power-Adapter-with-Variable-Outputs.html). It has the advantage of being able to lock the adapter into the preferred voltage output. So if you want modern high intensity lighty - you could use all 12v. For lighting from the 30s to the early 60s you could drop down to 9v or less (which gives a nice warm colour)

 

Another thing to consider, when adding lighting to a layout, is the choice of lighting method: LEDs (stay cool, last forever), Grain Of Wheat Incandescent Bulbs (get warm, can burn out if used at max voltage) or Grain of Rice Incandescent Bulbs (can get VERY hot! - enough to melt plastic)

 

F

[QWILPEN]

Hi

 

I dont know if this is of any use but my layout lighting 12v/6v/ and 3v is all supplied via an old pc power supply, ok the 6v is actually 5v but it works brilliantly for all the different lights i have grain of wheat bulbs, leds and even the different types of street lights available from China via ebay.

 

steve

[Dan Griffin]

I use an unregulated 12V dc power supply such as this http://www.maplin.co.../full/gs74r.jpg . I bought the appropriate socket to match one of the plugs, mounted it on the side of the baseboard and soldered bus wires to the connections on the back with droppers to switches also mounted on the side of the baseboard.

 

 

can you post a wiring diagramme please? and do you use one power supply to control all lights and would this work for signals aswel?

[28XX]

For applications where the physical size of the lamp is not too important eg lighting in enclosed buildings, ASDA have 20-lamp festive lighting sets for ??1.00. That's 5p a point. chop 'em up into singles and feed them all in parallel from a 12v ac or dc supply. Sorted.

[96701]

can you post a wiring diagramme please? and do you use one power supply to control all lights and would this work for signals aswel?

 

Not sure that I can actually draw and post a drawing, so I'm going to try a couple of photos.

 

 

If I've got this right, the above photo shows the ouside of the board with the socket on the left and a switch on the right.

 

 

 

This photo shows the other side, with flexible wires soldered to the socket, the other ends being soldered to the bus wires (a bit of scrap twin and earth domestic wiring), then droppers to the switch. I used the switch for operating Tortoise point motors until I got myself an accesory decoder, but have left everything else in place so that I can install lighting later.

 

HTH

[Brian]

Hi

Please remember that when using filament lamps these are often rated at around 60 to 70 milliamps (ma) per 12 volt lamp. Therefore 10 wired onto say a 500ma rated power supply would overload it! As at least 600ma or 700ma is being demanded by the lamps. LEDs of course consume considerably less current and are typically rated between 15 to 25ma per LED with a suitable series resistor per LED.

 

If you want a power supply to be able to power colour light signals, yard, street and station lighting plus perhaps any building internal illumination, I would highly recommend using a 12 volt regulated power supply. Regulated means the 12 volt output will be a constant 12 volt from a small loading to the maximim current loading of the PSU. No serious fluctuations in supply volts, as occurs with an unregulated PSU.

This example offers 1.2Amps (1200ma) at 12volts Regulated PSU-1

 

Whether you cut off the moulded low voltage plug on the end of the 12 volt PSU wires is up to you. You can (as already stated) obtain a matching chassis socket to the moulded 12volt plug and mount the socket on the baseboard or its fascia somewhere. Which would be my preferred method of connection.

 

Wiring is like this then.....

Note that I have shown just four 12 volt filament lamps, there can of course be more. Additionally I have shown how to connect filament lamps if they have 6 volt lamps fitted - two wired in series across the supply and finally how to wire LEDs each with a series resistor. Note; if the LEDs are rated at 12 volts, then no additional series resistor is required and they connect exactly like the 12 volt filament lamp. However, LEDs must have their correct polarity maintained and this applies to all types of LEDs. Normal the longer lead of an LED is the Anode (positive) connection. But this should be confirmed.

[Etched Pixels]

Two quick points I would add to this

 

If you are using filament type bulbs - ie not leds then

 

- Run 12v ones at 9v unless you find you want much higher brightness

- Use smoothed DC power if possible

 

Both of those will dramatically increase the bulb lifetime.

[18B]

I use an unregulated 12V dc power supply such as this http://www.maplin.co.uk/images/full/gs74r.jpg .

 

my local "home Bargains" shop is selling the above item (or something very similar) for only ??2:99! it has a variable Volt output upto 12V.

 

Looks perfect as a power supply to model railway lights.

[Jon Harbour]

Does anybody use adhesive copper strip to provide power to lights inside buildings? Are there any recommendations concerning size of the copper strip to be used?

 

Thanks

[Dr.Glum]

Hello Rhubarb,

I use power packs out of old PCs (PSU = power supply unit). (I believe there was a thread in RMweb3) Advantages: free or cheap, and apparently regulated. Disadvantage: lots of straggly wires to terminate or tidy up.

Over the years I collected old ones from work. They are about 10 years old and have the following outputs:

+5v 15A, +3.3v 12A, +12v 4A 48w, -12v 0.4A, +5v aux 2A.

Most of my lights are leds, so at ~20mA each, the above will support a lot of lights. More modern PCs were more power hungry, so the power packs give even more juice. Now, if you can get a PSU out of a server . . .

 

With regard to Jon Harbour's query about copper strip, if you use the stuff sold for DCC bus wiring there should be no problem of voltage drop in the largest building. (The stuff I use is 10mm wide by 10thou thick.) The major losses will occur at joints. I show here the underside of a fill-in cardboard scenery module that has buildings above, supplied at the edges and streetlights dotted around.

I had no trouble (or singeing) soldering onto the strips stuck to cardboard. (Don't linger too long with the iron!) The next image shows how I dealt with joins in the strip and the feeds to the streetlights (so that they could be removed if necessary).

The chocolate blocks are the smallest ones my local electrician sells (2A maybe, ~ 55p a strip). They are glued to the card with Evostick Timebond or Evostik Serious Glue. I have not yet used copper strip on any foamboard yet, but I don't see why not.

 

There was a warning about hot grain of wheat bulbs further up this thread. I support the warning, but circumstances vary. I was very concerned about heat before I stuck some inside a Metcalfe building. I ran a test with a bulb sandwiched between two pieces of card (the soft grey sort) and ran a bulb at 12volts for a while. It was too hot to touch with a finger, but on removal there was no hint of a smell or any browning. I was reassured about using them in the building. I did not do the test with plasticard.

Cheers, Tony