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GCA93_2_3_rail 6 port current detector for combined traffic on Märklin K-rail



By Peter Giling


Rocrail has many (and even undiscovered more) options. With this unit, combined with latest Märklin K-Rail, it is possible to run automatic traffic with 2 and 3-rail material MIXED. Some important (but not difficult) conditions:

  • 1- Each block needs separate GCA93_2_3_rail unit(s).
  • 2- Used trains should fit completely (so inclusive the last wheels) in the separated block
  • 3- Blocks are electrical isolated in both rails.
  • 4- All Märklin rail material should be able to be used in 2 rail driving.
  • 5- Märklin locs and waggons should not be used with 2-rail trains

How it works

If you are only interested in two rails systems, please skip his page, there is unfortunately nothing interesting for you here.

The main idea is to separate your Locs in two sections: 3- rail and 2- rail.
The unit contains 6 feed-back(sensor) parts.
This is limited to 6 because we need two ports to activate the 2- or 3-railsetup.

The idea is to have each route copied in a second equal one.
In each route there is a definition of the locs that are denied or allowed.
All routes in 3-rail should have included a command to switch one (or multiple) dedicated GCA93_2_3_rail unit(s) into 3-rail setup.
The same counts for all 2-rail routes where a command is added to switch the dedicated GCA93_2_3_rail unit(s) into 2-rail setup.
That is about it.
The unit itself is electically commanded in exactly the same way as any coil activated turnout.
Two ports should be configured as pulse output with minimal 200 mSec pulse.
The 4 bistabile relays on board are switched together, but the totsl current for that is much less compared to any tunout coil.
Apart of that a 12V ac/dc is required for that.
This power is complete isolated from the network supply.
This avoids (same as with turnout coils) that the network supply for the electronics will be disturbed.

Once a train has reached the IN sensor, it will free the previous block. (Standard Rocrail procedure).
Therefore, it is important that at that moment, the last wheels (achse) have passed the rail separation.
The midrail is constantly connected to red line of the central station.
And one of the railsides is constantly connected to the brown wire of the central station.
The other rail, this is also the one that is cut for the sensors, will be switched depending on 2/3 rail situation.
In 3- rail, this unit is using ground detection as type of sensing, in 2-rail, current detection is activated.

More to come

Pcboard, as supposed to look like the picture above, is in progress.
It will take some time because a special testlayout should be built, to be sure that all my promises wil come true.
To safe complex wiring, all wires to rails in a block are connected to this unit, making it very clear to understand what you are connecting.
A clear drawing of how to do that is also on my to-do list.
Beta tester is welcome.

gca93_2_3_rail-en.txt · Last modified: 2022/12/27 17:11 by phg