I am new to model railroading, building my first real layout, and in need of some advice from more experienced hands.

The design involves several Marklin 72442 braking modules attached to a 60830 decoder, controlled by an ESU 50200 central station. That all works fine; but I am having trouble understanding the required wiring for signals, which perform simply a cosmetic function in this instance.

I have a couple of Marklin 76391 coloured light signals which I want to use for visual effect with the braking modules. They are the later generation of the 76xxx signal series, which I understand should now work in conjunction with the 72442 braking modules. However, I do not understand the various instructions on how they should be wired up, simply to change colour with the switching instruction from the 60830 decoder. That is, as I understand, the signals do not perform any switching function for track power, but simply should change colour as the braking module is switched to "stop" or "go".

Would some helpful soul please tell me in simple terms which wires to attach to which connections, since I have so far had no success following the various Marklin directions?

Grateful for any assistance!

Rob

Ok Rob, here goes ... if anyone here on the forum wants to correct any mistakes I have made in the following, please feel free to do so.

Here is the first scan from the 03402 Signal Book, page 8-8



First, look at the drawing on the right side of the scan. This is the circuit board for the 76XXX digital signals. "A" is for connecting a distant signal, if applicable. "B" is used for switching track current on/off. "C" is for the power supply in conventional analog operation. "D" is a second relay contact. The relay on the board is actually a DPDT relay. Remember this for later. "E" is for analog connections from a control box. "F" is a permanent connection to the signal mast. Let's ignore "G" and "H".

The drawing on the left side shows how to connect the 76391 as a conventional analog signal controlled by a 7272 control box. In your case, it can be replaced by the K83 decoder. You would ignore using "B", the Brake Control Module is controlling the switching of power to the track. You would need to connect "C" to AC power as shown in the drawing. The last connection is to plug the 7272 (or K83) into the connector marked "E". There should be a 4 pin connector that came with the signal to use here. Before I continue, let me post another page ...



At the bottom of the bottom paragraph of the center column note the comment that 76XXX signals must be used in parallel to the BCM. I take that to mean that the signal connection to connector "E" on the 76XXX signal needs to connect to the same output of the 7272 (or K83). I assume there is enough power to drive both the BCM and the 76XXX signal from one K83 output. I have not tried this myself. If someone disagrees with this, just say so. I am not too proud to admit I am wrong.

I have been searching for info on the BCM and have found a couple of sites where you can make them yourself (if you are good with soldering and working with making a small prototyping board). Using a K83 to drive a 76XXX signal is kind of a waste since the signal has it's own digital decoder built in. The 72442 BCM carries a $100 list price here in the States and you can make one easily for under $10. Remember connector "D" that I mentioned above? I found a thread here on the Forum (I tried finding it again to give you the link but I am having problems searching on the forum right now. I wanted to give credit to the member who posted his research and findings). The link to his website is here:

http://home.swipnet.se/wes_familj/emj8.htm

Read thru it and check out the section "Deeper". Click on the link to the third method and he shows how you can make a BCM circuit that uses this extra relay contact from connector "D".

Ok, I have "rambled" on enough. I hope this helps you and solves your problem. Again if anyone wants to correct any of this, feel free.

Robert

Rob,

Welcome to the forum.

John

Dear Robert,

Your detailed reply has been most helpful. Indeed there is a 4 pin connector included with the signal; and from the comments in your scans it makes sense that wires from E, connected in parallel to the k83 decoder, should do the trick.

I had been puzzled, however, that the only diagram I found of 76xxx signals connected to the braking module shows 1 yellow and 2 blue wires from the signal. Such a wire set is not included with the signal. Instead, there is a green and a red attached to the 4 pin connector, shown as used in conventional operation. All a little confusing to a relative novice.

So, following your suggestion, I will connect the red and green in parallel to the k83 decoder (and then, no doubt, find out whether I was successful in giving the signal the same address as the braking module!) Unfortunately, it will be a week before I am back home to try it.

In the meantime, thank you once again for your help.

Rob

Hello,

is it easy, just comand your signal with one adress and the braking module with another adress (k83) in parallel by programming an itinerary witch is switching both at the same time.

I'm doing like this and I do not understand why it should be an overkill??? The signal looks fantastic and the normal on/off switch of the signal will be just replaced by a braking module. IT is not an overkill, it is a tuning of the high tech signal.

Advantage of the solution is, that I can run in the opposite direction just by commanding the braking module, the signal is still showing red (very prototypical).

If someone doesn't like to use up two adresses for this, he can make the connection between both using the diagram suggested by Märklin:

http://medienpdb.maerkli...102-Signal_und_72441.pdf

rgds

Stephan

That is an interesting circuit Stephen. Did it ever show up in a Marklin publication? I assume the B40 C800 is a rectifier. The only address used is for the signal which is using one of the DP contacts to supply either a positive or negative DC to the braking module. Interesting ... now does anyone have a source for the small two pin and four pin connectors used with the 76XXX signals??

Robert

Success at last!! I can report that wiring the 76391 signal in parallel with the 72442 braking module, as shown in Figure 9-27 of the Marklin HO Signal Book but with a k83 decoder substituted for the 7272 control box, works just fine. In doing so, I have set the same digital address for the signal as for the output from the k83 decoder.

The greatest obstacle in the exercise was Marklin's outdated instructions with the signal, relating to setting the digital address. Version 2 signals come with what appears to be a rectangular piece of cardboard held in place by a wire clip across the underside of the signal's control electronic circuit. Apparently this was part of the packaging in version 1, so that after setting the address you simply took the signal out of the pack and installed it on the layout. Now, after setting the address, the cardboard and clip have to be separately removed before the signal will operate in anything other than demonstration mode. No matter how you wire the signal for testing, if the cardboard and clip have not been removed, only frustration lies ahead. Remove the cardboard and clip prior to testing the wiring, and ... bliss.

Now, experienced hands would no doubt have dropped to this rather quickly; but for a novice, it would have helped if the instructions made some mention of needing to remove this innocuous attachment to the signal's control circuit prior to testing.

I can also report that the item B 40 C 800 in the circuit provided by Stephan is a commercially available rectifier, which I have on order.

Rob