Resources for electronic control (re: DCC Wiring Inquiry, etc.)

Regarding the recent thread on DCC where someone asked about a way to automatically control a turnout based on the presence of a train on the track leading to it, I ran across some stuff that, even if it doesn't answer that particular question, could be of value in other applications.

_Mainline Modeler_ ran a series of articles back in 1993-5 by Rich Weyand, describing a bunch of very useful electronic modules. These are "building blocks" which can easily be interfaced to each other, and to other devices like DCC controllers, RC controllers, etc.

Turns out these are nicely archived on a page on Rich's TracTronics site:

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Each module is fully described and can easily be built by anyone with minimal electronics skills. (They're also available as kits or assembled and tested from TracTronics.)

In the case of the inquiry about controlling a switch, you might want to take a look at two of these modules: DetectTrain uses current detection in an isolated track block to sense the presence of a train within that block, and SeeTrain is an optical detector to sense the presence of a train at a particular location.

There's other kewl stuff there too.

If you want to use every train to control a turnout, use a 1/4" isolated section of the common rail, an "end-off" point motor and a simple individual diode/resistor/capacitor capacitor discharge unit, One output of the CDU goes to the common wire of the two point motor coils and the other to the common rail.

I'm guessing you want to set a turnout for trains trailing through it. The 1/4" contacts need to be more than a train length from the turnout. The motor coils can still be operated by panel switches and/or by a reed switch and loco mounted magnet for a dedicated branch line train etc.

The CDU needs to be powered from a separate transformer.

Blacksmith engineering, but it works every time. =8^)

Regards, Greg.P.

David Nebenzahl wrote: