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Electrical Design Question

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  • Member since
    February 2004
  • From: North, San Diego Co., CA
  • 3,092 posts
Electrical Design Question
Posted by ttrigg on Tuesday, February 28, 2006 12:21 AM
As construction of the extension out to Green Apple Orchard reaches completion, I have started to "design" the next phase of construction on the Rosebud Falls Scenic Railway. A long, climbing timber trestle bridge up to the water falls.

My problem:
This uphill leg will be for the trolley car will using the LGB Auto Reversing system, powered by the transformer that came with my first "D&RGW starter set." As we all know it takes a whole bunch LESS power to go downhill than up hill. Since I want to use the automatic reversing unit here, I do not want to spend all day regulating the power. Are the any of you electrical geniuses out there that have a design, can design, or know of a design out on the net that will allow full power in one direction of travel and a much smaller power in the other direction?

If there is such a design available, is it idiot proof?

Tom Trigg

  • Member since
    April 2003
  • 305,205 posts
Posted by Anonymous on Tuesday, February 28, 2006 1:36 AM
Tom mate;

If you go to LGB MTS it wil solve your problem, it maintains a constant speed all the time; it even remembers your track configuration and allows for varyances in the conductivity of your track ( ie. dirty track etc) it will proably also do your reversing unit better. If you like you can go to a reversing loop with an automatic operation of the points (switch) in your reversing loop.

Aoart from this youy may be able to look at ciruitry of the reversing unit and see if it has a function that will invoke a circuit variation, which you may utilise to drop your voltage for the down hill trip to a predetermined level.

Failing all this, set the speed controller somewhere in the middle, so that it will go a bit slow going up hill and a bit fast going down.

Best of luck.

Rgds ian
  • Member since
    March 2002
  • From: Norton, MA
  • 394 posts
Posted by piercedan on Tuesday, February 28, 2006 3:07 PM
Upgrade the engine with a decoder that has back EMF.

MTS in my new Unitah by LGB has this feature and runs on analog power real nice.

I am sure there art DCC decoders that can do the same thing.
  • Member since
    December 2003
  • From: Coldstream, BC Canada
  • 969 posts
Posted by RhB_HJ on Tuesday, February 28, 2006 3:37 PM
OK, this one according to the KISS method.

Since the reversing unit just reverses the polarity, you use as many diodes as required in series to get the required voltage drop and insert them in one lead to the track and you use one extra diode in the opposite direction as a by-pass around the voltage drop diodes.

Diodes need to be of sufficient rating to handle stall current of whatever engine you're running!

PS Cost of complete gizmo approx. US$ 5
Cheers HJ http://www.rhb-grischun.ca/ http://www.easternmountainmodels.com
  • Member since
    February 2004
  • From: North, San Diego Co., CA
  • 3,092 posts
Posted by ttrigg on Tuesday, February 28, 2006 6:42 PM
[bow][bow][bow][bow][bow]

QUOTE: Originally posted by RhB_HJ

OK, this one according to the KISS method.


Thanks much HJ! I knew there had to be an Idiot Proof way that I could handle. Took your post to my local "Radio Shack" and the guy there knew just what I needed after reading your comment.

I just tested it out (on flat land) and the "downhill" direction is about a quarter of the speed of the "uphill" direction.

Thanks much! Problem solved.

[bow][bow][bow][bow][bow]

Tom Trigg

  • Member since
    December 2003
  • From: Coldstream, BC Canada
  • 969 posts
Posted by RhB_HJ on Tuesday, February 28, 2006 7:19 PM
You're welcome!
Cheers HJ http://www.rhb-grischun.ca/ http://www.easternmountainmodels.com

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