View single post by corv8
 Posted: Wed Mar 20th, 2019 05:14 pm
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corv8

 

Joined: Tue Nov 13th, 2018
Location: Vienna, Austria
Posts: 119
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Michael M wrote:
Not clear on the DCC problem with working overhead. 
Found some information that suggests that you can use DCC:

http://www.trolleyville.com/tv/school/lesson5_3/index.htm


Michael,

I think the trolleyville guys operate their equipment traditionally with both rails connected
(ORR switches are one piece  brass castings)
even on DC, so there is no basic problem with DCC.
However nothing else other than trolleys may run there. 

Back then, we  thought about converting a plain two rail DC layout with overhead,
so it was possible to run two or even three trains simultaneously, the old traditional way. 

Train 1 uses both rails.
Train 2 uses left rail + wire.
Train 3 uses right rail + wire.
 
Today, one of the big advantages of DCC is the easy way to operate reversing loops, and or Wyes. 
I cant remember details of the discussion 15 years ago,
but I seem to remember that a loco running on one rail and wire,
would fry the decoder when going through a loop or wye?  

I try to remember....  hmm.... 
DCC "circuit" #1 needs the rails, for diesels and steam. 
"Circuit" #2 uses left rail and wire... should work.

Problem arises when the loco leaves a loop,
either it hasn't current available because she tries to pick up from the "wrong" rail,
or somehow current from circuit #2 should be present in the other rail too,
this is impossible for obvious reasons.

Maybe somebody with more electrical knowledge than me can tell it better. 

A similar problem would exist with straight DC,
however in case of erroneous operation, there is no decoder to smoke up.
 
Hope my English, and electrical terminology, was sufficient to explain my thoughts?




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Gerold
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