Sunday 14 November 2010

The train on line 1 is running itself....

A long time since the last posting, but here is a train one...

For the Warley show this year, I will have a demonstration on DCC and 2mm scale topics. This will include some basic issues, such as how to fit decoders in limited space, and some more advanced topics, such as train detection, interlocking, and automation.

The advanced topics are illustrated with a simple track arrangement which can be run automatically or manually. A fairly rough video is shown below (bring back the old version of Windows Movie Editor, it was easier than the current one !).

The automated shunting sequence includes careful buffing up to the train, and if the loco running has lights, these are switched on/off at appropriate times.

The train detection is through MERG DTC-8 detectors which register current in a track section. Those feed their output to a HDL LocoIO board, which places the information on a LocoNet network. From the network, information is picked up by other LocoIO boards (displays status on LEDs, etc), and via a computer interface, to JMRI. The LocoIO boards also provide input from the manual lever frame, and output to LED signals at the trackside and servo motor drivers to move turnouts.

JMRI provides the interlocking for the signals rules, an on-screen duplicate of the lever frame, and the automation scripts which send instructions to run trains, change signals and turnouts, alter functions on trains, etc.. The scripts respond to the state of the track detectors. JMRI can track a named train around the system, so it is known which train is in which section.

Train movement comes from a Digitrax Zephyr command station, which relays instructions from LocoNet to the track. It also offers the manual running controller.

A second manual handset, a Uhlenbrock Fred, provides a hand-held controller.

And, if any visitors turn up with an iPhone with the WiThrottle Application loaded, they are welcome to connect it into the system and drive the trains on their iPhone.


Dave Keeler said...

Could you provide some more detail on the interlocked lever frame. I've currently use the P4 Society SHAG frame and a Lenz DCC system for train control but have always fancied interlocking the lever frame but not necessarily going the whole hog with DCC point control.

Nigel Cliffe said...

Dave, I'll try to contact you off-line as how the lever frame is connected could get very involved for a blog post.

Alexander Seal said...


Are the levers free to operate at all times with the the lights as indications of if they're able to respond, or is there an electric lock on each lever as well?

If you've managed to electrically lock the levers I'd love to know more about how you did this.

Too long for a blog post? Surely not!


Nigel Cliffe said...

No, my levers are not locked mechanically, its just lights. But I know *how* to do it; one of the MERG members has published a design which uses rotating "castle" locks below each lever. The castles are mounted on the output spindle of a small servo (one per lever) going through about 30 degrees between "open" and "locked".