Hello Nancy,
1. It all depends on the equpment. 72750 is easiest; only used together with 74xxx signals. 72710 is uses for "solenoinds with end shutoff contacts", which means Märklin C-track and K-track turnout motors. If used with M-track turnouts, or 70xx/72xx/76xxx signals they will work, but continously show both green and red indicators. 72720 is the better box for those. All boxes with five digits, have the new sockets; make sure you have the right plugs for those.

2. Märklin tunrnouts do not have any such built in function, contrarary to many 2-rail turnouts. But you may construct such functions by using a relay (7244 from Märklin, or from other make) connected in parallell, or a signal with train control (also in parallell with the turnout. No simple solution though.

/Lars

Thank you both. The 72750 control box is not that much more expensive than the 72710 rather than create something with a soldering iron. I can use one but this may wind up neater for me to go with the premade box.

I think I will put one signal after the turnout in the spur than try to isolate the turnout. Seems cleaner. The light signals are not THAT expensive. I imagine it could be done without signals too (a switch to control track current) but ...........

I think it's extremely simple. There are two cables to the signal; fed in one direction it shows green, in the other red.
So

R-->|--+
G--|<--+----- 1.5 kOhm --- signal --- 0

or something. Havent't tested it; I use Viessmann signals.

Same principle as DC-motor control.

/Lars

I think it's good thinking to wait with digital control of turnouts, but use digital for locos.
Are you using C-track (or M/K)? Easier to guide if we know.

"Turnout lights" may refer to the lamp which may reside in the turnout with permanent light, but more probably the red and green lights of the control box 72710. These lights use a trick; the turnout motor consist of two solenoids, one between yellow and one blue cable, the other between the yellow and the other blue. When a solenoid has done it's jobb, the blue cable connected to this is disconnected with "end shutoff contacts", which means that only one of the solenoids has contact at a time. Or, only one blue cable is connected with the yellow at a time. The LEDs in the control box draw the little current they need through this solenoid, little enough not to switch the turnout.

If a motor is used which doesn't have these contacts (signals, M-track), both LEDs are lit all the time (except the moment a button is pushed).

Yes, the decoder may be replaced; if C-track there exist a cable with this special connector, normally enclosed with the motor. Perhaps your dealer has one spare.

/Lars

I have long since given up on k84 , primarily because they offer only SPDT options but also the price. Instead I use a k83 with a diode-resister and a DPDT latching relay.

From this the two circuts can be used for lights and dead section control.

However - Any DP (double pole switch - manual of electronic) with a red and green LED ........



for k83 option



Note: not shown for the k83 connection are the back emf diodes recommended across the inputs of any relay

Thanks a lot for the circuit diagrams! It's really a simple connection inside these signals, with two wires and 2 diodes. Just one disadvantage that you can only have 2 states (red/green). Maybe I'll buy one control box to use for testing anyway (and for switching yard signals and other manual signals).

I want swedish signals on my layout, and they look a little different, so I will use a different make of signals. Since they are only sold as kits, I could just as well use the same approach as Märklin, at least for the simple signals with 2 LED's (red/green). Now I just have to find out how to make flashing distant signals...

Interesting ...

Well, there are similar kits available for swedish signals, but without digital control. The swedish signals have a green and red light for the main signal. The distant signal is flashing green for stop(!) and flashing white for go. Flashing LED's is one way to go, but I don't think they are available in white, and they are pretty big as well.

There is a kit available that controls all aspects of a swedish four-light signal, but it doesn't have train control, and it can't be controlled digitally. It has detection of wether or not the following track section is occupied, and then provides feedback to the preceding signal to give the correct distant signal aspect. With a few relays I think this will be the right solution for me. It also gives a smooth transition of the lights, which is a nice feature, especially for flashing lights...