Peter, this question totally depends on how big your layout is, or more specifically how many trains you will be running at the same time and what capacity your Transformer(s) are.

You certainly 'can' (in theory) run them all off one Trafo, but if you only have a small 10Va Trafo, it's really only designed for starter sets with one smallish loco.

Not enough current, things will stop or not work reliably. Best simple analogy I can give you is if you've ever been using a shower when the water has suddenly slowed to a trickle or gone suddenly cold because someone else has turned on a tap, flushed the loo, washing machine going etc - that's much the same effect as an under-rated Transformer. More outlets want water than the pipes can deliver. Simple as that.

Somewhere I'm sure I once saw a chart that gave a breakdown of the power consumption of a range of Marklin items - if I have it, it would be saved on my Desktop PC not due to arrive from Oz until next week. (Or perhaps I intended to create one and it's still in the 'to-do' list)? Perhaps someone else has one to contribute?

Anyway, on average a small loco may draw close to 10Va in operation, just in running around the track. Add a few wagons and this will increase a little, but add wagons with Lighting and it will increase a lot. Allow around 3va per lighted wagon. Larger Loco's will draw a lot more, something like a Crocodile or large Steam Loco may draw 2-3 times more than a small one. If the Loco has lighting, again add around 1.5va per lamp. Even the little old 3000 Cl89 may have 2 or three headlights, so that loco could draw in excess

Individual lights such as platform or street lights, lamps in buildings, AND each signal lamp (and turnout lantern) allow around 1.5va per lamp.

Add all these together and you'll have your total current consumption. It must be less than the rated VA of the transformer otherwise things won't work as they should.

And don't forget to factor in the current required for a short burst to actually change the signal (and turnouts). It's only needed for a short time but if all your Trafo capacity is being used to run a loco or two, and all the lights, and then you try to change a signal or turnout you may find it won't activate reliably.

Many people do separate the lighting to a secondary transformer so that full power is available to the trains. 10va Trafo's are fairly limited for train operation, but very good as lighting controllers, and they have an added bonus which is that the can increase or decrease the brightness of the lamps. Advantages of decreasing the brightness is that the bulbs will last longer, and if you like to run your trains at night (a personal favourite of mine is a lighted layout!! ) the 'daytime' brightness of signals can be overpowering.

I just did some quick checking, can I highly recommend (ie strongly suggest) that you download the Marklin handbook "Marklin Miniature Railway and it's big prototype" here, (scroll to the bottom and select "Miniature Railway HO" - right-click on it and select "Save as or Save Link as..." and download it to your PC). The version there is in English. The cover image shown is attached below my message so that you know which one I mean. But heck while you're there, grab everything while you can.

The whole 0753/2 book is a very good read and in my opinion is quite an under-rated book, even allowing for how old it is (Oct 1955). The specific info relating to this particular topic starts at page 57 and explains what I've outlined above with some specific examples.

I reckon this book should be mandatory in the library of ALL Marklin enthusiasts because the basic principals and theory still apply today even (or even more so) in Digital.

Hope this helps

Cookee
Wellington

Edited by user 28 July 2012 10:33:58(UTC)  | Reason: Clarification of explanation

Thanks for the info Cookee i wiull have to go out and get a second transformer then for i want to run mine at night with lights and signals. and thanks for the link to the library have downloaded all those manuals and will print them out one at the time over the next few months so then ill have a half decent refernce library.


Yes River thats my NIck name LOL Farkenoath not farkenouth, if you want ill add an explanation to it one day.

Peter

According to the manufacturer, these allowances are given for the various items powered by the Marklin transformer:

3-axle tender locomotive #3000 draws about nine Watts (VA),
express Diesel locomotive #3021 takes about twelve Watts, and
the heavy express steam locomotive #3085 [probably with smoke unit] about fifteen Watts

each lightbulb counts for consumption of one Watt

I've seen that information published so many times in the catalogs it was almost given from memory. Since you're only powering lights and signals, the fact that most offerings are now digital should make little difference.