Adding Directional DCC Lighting to a non DCC Ready loco

[Chrissaf]

These links may be helpful:

http://s374444733.websitehome.co.uk/class-156/index.htm

http://s374444733.websitehome.co.uk/class-156sound/index.htm

This is what inspired me to do my Class 156 as so

[Chrissaf]

I can't give a guide for your particular loco regarding the physicality of your request, but the schematic below shows how you how you wire in directional and cab lighting to a Hornby R8249 decoder.

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...and more to the point, how to connect them to a new Hornby 8-pin decoder...

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LEDs are polarity sensitive and have a positive and negative side. Connect them the wrong way round and they don't light up. The triangles representing the LEDs point towards the negative wire connections. On a standard round LED, there are two connection legs. The longer leg of the two is the 'positive' connection and would connect to the 'Blue' wire via the current limiting resistor in the schematic above.

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Directional lighting works like this. When the R8249 decoder receives an F0 command from the DCC controller, the decoder directional lighting is enabled.

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If the loco is commanded to move forward then the decoder 'White' wire is switched negative. In the schematic above, white negative lights the white front loco LEDs and the rear red LEDs.

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If the loco is commanded to go in reverse, then the negative on the 'White' wire is disabled and the negative is enabled on the 'Yellow' wire instead. Now the yellow negative lights the rear loco white LEDs and the loco front red LEDs.

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This requires four LEDs at each end of the loco. Two white and two red. Eight LEDs in total for the complete loco.

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The 8 pin socket in the schematic above are readily available on eBay with pre-terminated wires, making adding a socket to a non DCC Ready loco a doddle.

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Scroll down a few listings on this page.

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Scroll past the 'From Germany' listings, these are too expensive. Look nearer the bottom of the page.

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I suggest this one as a possibility if based in UK

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[Chrissaf]

Hi all, if you've read my recent post re Class 156 couplings this may add a bit of meat to the bones: class 156s are my true loves! I've picked up a few relatively new Hornby models for peanuts - long story short they're in poor shape. I'm respraying/renumbering them, recoupling them and want to add lights. I already have my plan for amber stopped lights and coach lighting but I'm desperately seeking a comprehensive guide to installing directional lighting. I know I'll ahve to drill through the pained red and white 'lights' but I want to know what equipment I need and more to the point, how to connect them to a new Hornby 8-pin decoder.

[Bulleidboy]

This might also be of some help - 

[WelshTyneside]

Thanks for this. What is the best way to actually connect it together?

Theoretically we could be looking at three different running modes:

Forward Day

Forward Night

Backward

Obviously the directioonal operation is very straightforward but how do I tell my decoder I want the lights to be rubnning as night? Also what is the actual best way to connect multiple LEDs to a decoder?

[STG]

 

Theoretically we could be looking at three different running modes:

Forward Day

Forward Night

Backward

 

To operate this you need at least a 3 function decoder (standard).

 Also what is the actual best way to connect multiple LEDs to a decoder?

Do you mean ie in the case of it has two LEDs for the rear lights? These LEDs would be wired in parallel - if one blows the other stays on

how do I tell my decoder I want the lights to be rubnning as night?

You would normally wire night-mode lighting to another function, ie. F1, and then perform function mapping etc.. (depends on the decoder)

[ColinB]

I fitted lights to my old Hornby class 43, I only did front and reverse. To feed multiple leds you can either buy a single in line (SIL) commoned resistor pack where one pin is commoned and goes to pin 7 of the DCC connector and then each led is hung off an individual pin of the restor pack. The return from the leds either go to pin 6, pin 2 or pin 3. Alternatively you can buy a small pcb off LaisDCC which does the same. If you have the room you can use individual resistors. The commoned SILs are great as they take up little room. As for function F0 normal lights, F1 night lights. Or you could do something clever with extra PNP transistors.

[WelshTyneside]

Hi all, thanks for your many replies. I suspect what is happening is I'm not being too clear with my questions. I have the Hornby 156 DCC Ready logo in Northern/RAF livery and have fitted a R8249 decoder.

I plan to add coach lighting in both coaches which is an automatic LED strip from Train Tech going in this week. It also has LEDs for the amber train stopped lights which just require a drill. So neither of those are related to my decoder.

Now then, my directional lighting. This link (http://s374444733.websitehome.co.uk/class-156/index.htm) gives an idea of the three settings of directional lighting I want to achieve. Forward daytime, forward nighttime and backwards/rear. For the LEDs I'll use those from DCC Concepts (2mm tower) with built-in resistors. I guess, as something of an electrical novice I have a few questions; 1. I'll be running wires from the decoder into the dummy car for its own lighting. How do I 'split' these wires so that I can use them for multiple things. 

[Chrissaf]

The article you have linked to is using two TCS branded decoders FL4 & MC4. Both these decoders would appear (according to the article) to support 'Function Mapping'. The Hornby R8249 is too basic and does not support this 'mapping' feature. You are unlikely to be able to replicate the documented project in full, if you continue to insist on using the R8249 decoder, particularly if you want to only have one single decoder shared across both cars. I suggest that you follow the article as written in its entirety rather than trying to amend it to save some pennies IMHO.

[Rog RJ]

I agree with Chris, you can't do what you want to do with an R8249 decoder.  It doesn't have enough functions available and it can't be remapped.

 

BTW The two decoders used in the linked article are a bit long in the tooth now.  If I was contemplating doing this mod I would probably go for a single Zimo 6 function decoder.  I think you could do it with a 6 function one but I'm not sure about that.

[ColinB]

I think you can possibly do this with a Hornby decoder, but you would have to look at adding some diode logic.

Rear lights are driven via function 0 or 1, and different bleed resistors for the headlight leds dependant on the function.

[96RAF]

On this page in addition to the linked to article above there is another link on the index page to the more basic Express Models lighting conversion.

Scroll down here to Hornby diesel/electric locos.

http://www.bromsgrovemodels.co.uk/decoderinstallation4mm.

Although the link to this alternative installation page bombs it indicates the original link came from the RM Web forum so it may be worth taking a look over there or seeing if you can get hold of the Express Models 156 lighting installation as they normally use small diam tower leds and their connecting pcb is easy to knock up on veroboard. Their instructions normally tell of a basic or complex fit depending upon how many functions your decoder has.