Hi, I am trying to write a short document about common ground use in Märklin layouts and I have been searching on the forum, but I am not able to find the information I am looking for.

It is clear that 6015 and 6017 boosters admit to build a layout with "common ground" over the rails, and also they can shar the source transformers.

It is clear that 60173 DOES NOT allow for "common ground" (due to its power output stage in "H bridge mode")

It is clear that 60174 DOES allow for "common ground"

It seems that 60213 DID NOT allow for "common ground" (???)

It seems that 60215 DOES allow for "common ground" (???)

It seems that initial versions of MS1 didn't allow for "common ground", latest DID. (???)

It seems that 60212 DOES allow for "common ground". (???)

At the end of the day, this is somehow a bit mess of unclear information.....

Is there any place where we could have a clear list of which devices allow for "common ground" in the rails, and even further, which ones allow for sharing the source tranformers or power supplies?

Or could anyone of you have such a list or help to build a final one with the information each one of us has?

I would include, if possible the CSs updated by ESU and also the ESU ECoS station or any other brands to have the list as much comprehensive as possible.

Standard S88 users (among many others) will thankfull us if we are able to build such a list as much comprehensive and clear as posible

Kind regards

Javier

Common ground: To be able to have one (the "ground" or the "common") cable output of all the boosters (including the control station) connected to the rails and not isolation in the rails.....

60173: First booster with "H bridge", but without any galvanic isolation, it doesn't allow for a "common ground", of course not with common external power supply.
60174: correction of Märklin over 60173 (and freely changed for it), it may have "H bridge" in the output, but it has "galvanic isolation" between the signal input and the output stage....

These are examples of such confusion problem, some versions of the central stations have such "galvanic isolation", some doesn't, and this is the reason I am trying to build the correct list. People can have older, intermediate and newer devices and such a clear list will be very helpful, I feel.

Rgds.

Javier

Hello,

With all "Old digital", I mean, 6021, IB, 6015, 6017, it is allow to use a common ground without problems, regardless of the transformers to feed digital devices.

The problem start with the "new digital", up to now, I mean from CS1 to CS5 or whatever, in this case, the gold rule must be, "each digital device must have his own transformer (or power supply)", without exceptions, this trafos or power supplys must feed only its assigned digital device, once this habeen accomplished they can use the common ground in the output stage.

The 60173 is a bad design and should not be used in any case.

The Mega-trafos are not allowed with the "new digital", but can be used in layouts with the "old digital", while the new digital keeps their own trafos



In this picture You can swap the 6021 or booster by new digital device without problems.

Is is my opinion

Best regards