Loco and Coach Lighting
For the digital experts: how critical is it to change the bulbs over on locos and coaches when switching from analogue to digital? What is the impact if you don't? Are the lights just dimmer/brighter or could it lead to permanent damage?

Paul, In the marklin world, you do need to change some locomotive as the will blow. I have heard of no issues with coach lighting. One thing to think about is that putting lighted coaches onto your layout reduces the amount of power on the track for the locomotives. I would suggest using LEDs for coaches wherever possible (and a function decoder so that you can turn them off when they are in your passenger sidings) John

Paul, Trix recommend 10V replacement bulbs for Analog coach lighting and 16V for Digital in their current coach set for "F-Zug Merkur". The lights already fitted aren't actually specified but they're not very bright on, say, 9v Analog running. Incidentally, these coaches are virtually identical to those in the earlier Fleischmann "F-Zug Gambrinus" set except for the steps (solid rather than a grating) and the printed Zuglaufschilder. They even have Fleischmann wheels. The 16V bulbs fitted today in most "Digital Ready" Analog locos give a very poor light on Analog. It often costs time and money to "change down - quite a lot of each in the case of the Roco BR 50 622. I broke two of the six flat conductors in the tender printed-foil unit, which has to conform to a very small-radius 180° bend between base and top tender weight/motor clamp. NOT a good design, at least for a ham-fisted old engineer. David

John, A neat idea to use LEDs. A function decoder in each coach sounds v expensive. My layout is wired in sections for analogue operation. For digital ops I just throw all the power switches on. However this gives me the option of switching off digital power to a siding with coaches, thus switching off the lighting. David, Thanks for that. Actually I rather like the dimmer effect of the digital bulbs as otherwise the lighting seems too harsh. As to power consumption, I haven't noticed a problem, but then I have a fairly powerful transformer to power the track (and coach lights) and only run about 4-5 coaches maximum. All the points, signals and houses are powered on separate transformers. All I now need to do is split the house lighting off, so you don't get that flicker when you change points! My main concern is to avoid any overheating due to using the wrong bulb which might melt the plastic or cause other damage. Doesn't seem as if anyone has had that experience...

If you make a single lighting circuit throughout a rake of coaches then you only need a single decoder and, of course, with so many axles making contact you have no flicker.

Hi Paul, Perhaps I wasn't very clear about my comment regarding function decoders. By using current conducting couplers the idea is to run a bus through the train. I would envisage running the lights of 3 or four cars from one function decoder. What you an do is recycle old locomotive decoders and use one of the function outputs for the carriage lighting and one for the carriage tail lights. That way if the carriage with the function decoder is the last wagon in the train, not only can you turn the lights on and off, but you can also turn the tail lights on and off as well. I have not done it yet, but have given it a bit of thought. As to power, most (and this is a generalisation) will let you run 4-6 non sound locomotives with out any problems. This reduces by half when you have sound locomotives hissing away. As a rough estimate, 5 coaches with bulbs could potentially have the power requirements of one non sound locomotive. When you start adding up the power consumption, it really does not go very far at all. I currently only have two sound locomotives (hopefully four by the end of the year) and as a consequence have been doing some research into the different digital controllers. Zimo is starting to look like a real option, even if their base unit is the most expensive on the market, but it does have the most power. John

John, Hmm. Interesting. How do you envisage the link between coaches? A surreptitious pair of thin black wires above the couplers or those fancy wired couplers?

Paul, I looked really hard at the old Roco 4 pole coupler, But they are expensive and not easy to uncouple. Märklin have released a single pole coupler that is very similar to the Krois (?) coupler and looks like it may do the trick. Admittedly it is only single pole. I would use each coach as its own earth and the single wire bus for the power. This means that you have three types of carriages: One with a decoder and a current conducting coupler at one end One with current conducting couplers at both ends One with a current conducting coupler at one end but no decoder in it. Using the new Marklin Couplers, you could in theory shunt carriages without their lights on in and out of train consists in your passenger sidings. Move them to your station. Turn the lights on, and away the train goes. Sounds simple but, in practice I would probably leave the train as a fixed consist and just turn the lights on and off as necessary! John