Friday, June 13, 2008

More thoughts on how to control trains

I'm still trying to figure out wht I really want. Use advanced features to control trains, or keep things simple and economical (so I don't need computer assistance).

While I don't really want to write software (no time to do this right), using computer control sounds very sweet. This would require I stick s88 control points at every switch and track that will hold more than one loco.

The first problem is how to identify locos. There are several commonly used methods:

  • Cut one rail of Maerklin K track and use the loco and car axles to bridge the cut. This is very common, and well supported with s88 modules. The drawback for control is this method can't differentiate between locos and cars, and I have a bunch of M-track on my layout.
  • Use a powersensing circuit to identify if a section of track is occupied by a train, and hook that up to the digital system. This works but isn't well suited for control because it's not very location aware. However, it's good for use in hidden staging to figure out which tracks are occupied by a train.
  • Use a s88 control point that is trigger by the power pickup shoe of the loco. There are contact tracks made by Maerklin, as well as several build-it-yourself approaches. This works well for control if you mainly run freight trains. The method can't differentiate between the pickup shoe of the loco, and a pickup shoe, that e.g. powers lights in the passenger cars, or the rear illumatination of a freight train.
  • Use reed contacts between the rails and a little magnet on each loco. This method clearly identified locos. However, each s88 contact needs to be made from reed contacts which are visible between the tracks and cost additional money, and each loco needs to be fitted with two small magnets.
  • Uhlenbrock offers LISSY which is a digital control system to solve the problem. It's clearly the most complete and powerful solution, but also the most expensive.

In what situations do I need digitally controlled stops?

Stop a train before a signal that shows red automatically.

  • Trains should stop in front of a red signal and preferably decelerate before coming to a stop.
  • Most digital locomotives don't roll very far when the loco looses power, so I don't really want to run them into section of track with no power (like in the old analog days).
  • On a green signal the train should accelerate automatically.
  • lights and functions should remain on while the loco is stopped.

Thursday, June 05, 2008

Digital model railroading for real now

The Intellibox and transformer finally arrived after many shipping delays. After dinner I set up a little bit of track on the dining table and connected everything. My only digital loco BR86 was used as guinea pig. Low and behold, as soon as I set it on the track it ran. It still remembered the speed setting from the store when I tried it out. With some trial and error I figured out the loco address, and was able to control all functions from the Intellibox with minimal fuss. The one irritating thing is that the speed steps are extremely coarse. At step 1 the loco creeps along, step 2 it moves ok, step 3 it feels like full speed, but there are 14 steps total. I need to find a way to reprogram the speed range on this decoder. Looks like it's a fairly new Marklin mfx decoder, which is not supported for programming on the Intellibox. Bummer.

Speaking of which, the connector on the Marklin transformer I got is amazingly whimpy and easily slips out. Not very convincing.

Mit viel Verspaetung kamen heute die Intellibox und der Trafo an. Gleich nach dem Abendessen habe ich alles angeschlossen, etwas Schienen aufgebaut, und die BR86 als Versuchsschweinchen auf das Gleis gesetzt. Zu meiner Ueberraschung fuhr sie auch gleich los. Sie hatte noch die Geschwindigkeit und Richtung gespeichert von als ich sie im Laden ausprobiert hatte. Mit etwas Rumprobieren bekam ich die Adresse des Dekoders heraus und konnte die Lok problemlos mit allen Sonderfunktionen steuern. Das einzige Problem ist dass die Geschwindigkeitsstufen des Dekoders zu grob sind. Bei Stufe 1 kriecht die Lok. Mit Stufe 2 geht's ganz gut, Stufe 3 wird schon recht schnell, insgesamt hat die Lok aber 14 Stufen... Das muss ich noch in Ordnung bringen. Die Intellibox understuetzt aber nicht das Umprogrammieren von mfx Dekodern. Mal sehen...

Der Stromstecker an dem Maerklintrafo rutscht sehr leicht ab, und ist erstaunlich instabil. Nicht ueberzeugend.