Electrical ooops

[Anonymous]

hi,

I designed a garden layout that looks like this,

_ _
\_\_______/_/

The track loops back on itself. I put insulators on the switch rails to allow the
train to run on this track. But it is all manual operation.

When the engine completes one of the loops, the polarity is reversed. So
I need to through the control throttle in the opposite direction. How do I
resolve this dilemma so the train can run continuously?

Is there an electronics solution to handle this. I just want the choo choo
to run without any intervension. [:(!]

thanks,

Mike

[grandpopswalt]

Mike,

As far as I know there's no easy way to do it "hands off"(this is one of the many reasons why I use batteries). You'd need to isolate the loops, have a sensor detect that the train is completely in the loop, disconnect the loop from the mainline while maintaining the original polarity, have the sensor signal a relay to reverse the polarity of the mainline so that when the loco returns it will receive the proper polarity of voltage.
I guess that this may be the main reason there are far more "dogbone" than loop-to-loop layouts.

Good luck.

Walt

[tangerine-jack]

Good news is that yes, automatic block control is possible. The best advice I can give on how to do this is the book "Wiring for Model RR" by Kambalsh, available at any hobby store. I have seen many articles in Model RR magazine pertaining to this type of wiring also, using either a magnetic reed switch or photo optic switches. I also have a book I think is called "101 Electrical Projects for MRR" (don't quote me on the title!) that has 2 or 3 projects that will help you. Go to the Kambalsh web site or your local hobby shop to order these books. Good luck![oX)]

[Anonymous]

Got this pic off another forum, shows automated switch without electric. The Idea is the safety pin holds the switch in the position the train will always comeback through in the opposite direction. when leaving it will knock the switch so the train will enter on the return trip on the side it left. I'm confusing I know. If unclear write back.


Photo courtesy of Torby- MLS

[Anonymous]

Like a return spring?

[Anonymous]

QUOTE: Originally posted by Bluebonnet - 71

Like a return spring?

Yep, The saftey pin has enough tension to hold the switch against the rail. The wheel flanges on the engine knock the switch into the opposite position. Keep in mind, this is great for battery, but you would still have to switch the power going to the rails for trasck powered layouts.

[Anonymous]

Do I understand from your schematic that the only problem is reversing the polarity on the main line after the last car clears the turn-out (switch) into the reversing loop? If so, all you should need is a double-pole, double-throw, momentary contact toggle switch. As soon as the last car clears the "turn-out," throw the D.P.D.T. and then open the "turn-out" to the mainline and the polarity will be correct for the train's reentry unto the mainline. Any hobby shop dealer should know exactly what you need. It really isn't as bad as it sounds and it will save you from messing with the throttle on the power pack. If you are using manual turn-outs (switches), you could mount the D.P.D.T. switches on the board adjacent to them. It has been a long while since I used standard wiring, so please check with your local hobby shop before purchasing anything. Best of luck.

[Anonymous]

Bobfarkus, The modeler who came up with this uses battery power so the polarity thing isn't an issue. Lgb does have a automatic reverse loop setup, but I'm told you can make on easly and cheeper from parts from Radio Shack.

[Anonymous]

[#welcome] Bobfarkus

Enjoy your stay!

[Anonymous]

Thanks for all the great advice. I'll look into the suggestions and post back .

thanks!

Mike