Coach/wagon lighting-circuit and suggested setup.

Discussion in 'Tutorials' started by Keith M, Jul 29, 2018.

  1. Keith M

    Keith M Staff Member Moderator

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    After posting on a recent thread regarding updating Triang/Hornby Mk1 coaches lighting-wise, I was PM'd by a recently joined member asking why he couldn't find my referred to "How-to" about the circuit and general setup, so as it appears this info may have been lost in the forum changeover to Xenforo, I thought it might be helpful for any other of our newer members, to post it up again for reference. At this point, I must state that this is just the circuit and method I use, and several other ways of doing this, including a fairly pricey ESU kit for carriage lighting (Circa £18!!) are available. If you have a fair number of coaches/guards vans etc to light, then by buying the components in bulk and making up the circuit boards yourself, it's easily possible to build the circuit boards yourself for less than 50p a board, so you can light a lot of coaches for the price of one ESU kit. That said, here's the relevant circuit.

    IMG_0230.jpg

    As can be seen, my 'standard-fit' board is quite small at 27x16mm, but it's equally possible to make it smaller still if you wish, as the 4 diodes and resistor could be vertically mounted rather than flat to the board, so fitment in "N" gauge is feasible. At 71, my eyesight is not good enough to go smaller, so this'll do for me!
    Keith.
     

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  2. Keith M

    Keith M Staff Member Moderator

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    I've made up probably getting on for about 50 of these boards and the pickups, so from time to time, I get a little 'production line' going and make up a batch if I think I'm going to be needing some. (Just bought 5 Bachmann Mk1's on Ebay, so another batch coming up!). Pickup's are easily made to suit different bogie's, but for Triang/Hornby coaches, I find the ones shown in the pic below work well. All they consist of is a strip of Veroboard, width to fit between the bogie, copper strips cut or filed away across the middle, and two short pieces of brass strip (2 or 3mm wide is ideal) soldered to the copper strips and bent to suit. In my experience, I find brass strip rather than brass or phosphor bronze wire works better, but that's just me, the choice is yours. I then glue the Veroboard strip to the bogie using Araldite (Hornby bogie plastic is funny stuff, and Superglue doesn't seem as effective to me), passing the wires from the circuit board to the pickups via the sizeable rivet hole in the bogie centre. Once soldered on, you're good to go. IMG_0218.jpg

    As you can see, it's all pretty simple.
     
  3. Keith M

    Keith M Staff Member Moderator

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    Here's a simple way to make loco lamps (at least, in 4mm stuff). I use the 1.8mm 'block type' LED's, supergluing a tiny piece of thin brass strip (or wire) in a "U" shape, across the end of the LED to form a 'handle', then dip the LED into black paint a couple of times. The reason for this is that you only want the LED to show out of the 'lens' at the front, not have the whole lot glowing! Once you have a couple of coats of black dried on, you can either leave it like that or dip it into white paint, once fully dry, just clean off the paint on the front 'lens' area, and it's ready to fit, either to loco's, guards vans, coaches etc. Here's a pic of a couple just 'lashed up' to a battery to illustrate what I mean. IMG_0212.jpg
     
  4. Keith M

    Keith M Staff Member Moderator

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    Now a red one. Don't forget to fit a resistor in series with the longer lead otherwise 'POP" goes the LED! IMG_0213.jpg
     
  5. Keith M

    Keith M Staff Member Moderator

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    For coach lighting, I'd suggest buying either the aluminium backed LED strips or a 5 metre roll of same, depending on how many you need, and all available on Ebay from a number of Chinese sellers very cheaply. One thing you will need to take into consideration is the total load of all these lamps on the layout supply, as in the form I make these lighting setups in, they're not 'switcheable' on/off. If you wish to do this, then you'd need to buy 'function only' DCC decoders, and fit/program these in each coach to turn on/off the supply from pickups to circuit board as needed......more cost/complication, but certainly 'do-able' if that's your bag. Anyone wanting further help/suggestions, then just either shout out or PM me, no problem and I'll help if I can.
    Keith.
     
  6. Toto

    Toto I'm best ignored Staff Member Founder Administrator

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    Wait until his nibs she's this. You've started something now. Very good Keith. :thumbs:
     
  7. jakesdad13

    jakesdad13 Staff Member Moderator

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    Hi Keith, whats the wiggly bit on the +ve out put?

    Pete.
     
  8. redpiperbob

    redpiperbob Full Member

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    Hi Pete that,s a resistor
    Bob
     
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  9. Timbersurf

    Timbersurf

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    For the basics and all the options see my Coach Lighting Guide. As yet I have not perfected the circuits (still being developed), I have ones that work for me, but I aspire to create an ultimate circuit that caters for every eventuality, certainly doable in DCC, but may be "Pie in the sky" for DC!
    Some of the less obvious pitfalls are:-
    Not using Schottky diodes will deform the DCC waveform (but you may well get away with with no impact)
    Not fitting a second resistor before the capacitor may give an overload of the DCC command station on start up (not an issue unless you have high load and small power command station)
    Selecting the right size of resistor after the capacitor will be dictated by DCC voltage, it needs to be different dependant on DCC voltage setting (12 to 22v on different systems), best to start high and reduce value to desired brightness (also dictated by personal taste)
     
  10. DomMorris

    DomMorris Full Member

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    This is great, thank you Keith, I was looking for this!

    Could you do me a favour and take a close up photo of the underside of the main board you have made? It's been a good 15+ years since I did any actual electronics (not counting making stay alive units and wiring in decoders!) so it would help if I can actually see it "in-situ" as it were.

    Cheers,

    Dom
     
  11. Keith M

    Keith M Staff Member Moderator

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    No problem Dom, although I'm not sure if this pic will be any help. It's quite possible to reduce the boards size further if your eyesight is better than mine (or you're a Micro-Surgeon!), but this size seems to fit ok in all the coaches I've done so far including Lima and Bachmann, and goes easily into guards vans etc. If you are building a current era layout (mine is late 50's/mid 60's) and coaches have a flashing red lamp to the rear, then just substitute a flashing LED for the standard one. As regards component buying, my nearest large town (Chesterfield) has a specialist electronic components shop (JPG Electronics) which I sometimes buy stuff from, otherwise everything's available on Ebay or from other component suppliers online, such items as the 1N4001 diodes and 1Kohm 1/4 Watt resistors are very cheap in packs of 50 or so, and you'll use them if you have much lighting to do. The actual choice of resistor value is dependant on your DCC track voltage, my Lenz controlled track voltage is 16 volts, and to me at least, the brightness level in daylight is about right, but if your voltage is different or you want more or less brightness, then just either try different value resistors or 2 1Kohm resistors in series to make the LED dimmer, but don't forget the resistor altogether, as most LED's have a maximum voltage of 1.5 to 3 volts, depending on colour.
    Keith.

    IMG_1273.JPG
     
  12. DomMorris

    DomMorris Full Member

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    Thank you very much Keith! I will attempt to get my head round this one, or worst comes to worst just experiment and see what I come up with!

    Cheers,

    Dom
     

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