Short at diamond in double crossovergreenspun.com : LUSENET : Wiring for DCC : One Thread
Our club uses Shinohara double crossovers with a Digitrax chief system. At the diamond in the crossovers a severe short occurs as each powered (or car lighting) axle passes over the gaps. Sparking can be seen easily. Of course this causes the system to do strange things - especially DH121 equipped loco's. I have seen a similar question asked by Dick Beebe in a British mailbag, but have not found any answers. I have read Allan Gartner 's page on the Shinohara double-x but Iam not sure he addresses the diamond gap issue. Does anyone have a fix for this problem?
-- Greg Brown (firstname.lastname@example.org), November 05, 2000
I have the same problem with a Shinohara double crossover. If I can say this without being sued I tell everyone that the Shinohara double crossover is an electrical disaster. Allan is more polite but his message is the same.
Anyway, my solution was to create a separate electrical section for the crossover and feed it through an automotive light bulb (as Allan suggests). I also provide power from a booster or automatic circuit breaker that has a delay in the short circuit protection so that the bulb will work reliably. (See my other post from a few months ago in another sction of this Q&A piece.) The result is that while the affected train may stop or jerk as it goes through the crossover, the rest of the layout is unaffected.
Hope this helps.
Dale Gloer Also, you might want to talk to Digitrax about your DH121s. Some early ones had problems with power interruptions. Digitrax replaced one of mine for htis reason.
-- Dale Gloer (email@example.com), November 06, 2000.
The track shorts occur when metal wheels cross the frogs. Shinohara doesn't bury the electrical connection of the rail being crossed into the plastic frog so that it is insulated. The wheel tread rests on one rail while the flange touches the other. The insulated frog points are also too narrow. A wide wheel tread sometimes touches both metal rails.
But there is a simple solution...Throw all 4 switches of the double crossover to be R or N at the same time. If you use manual throws, this can be a pain. But with electric switch machines, simply wire 'em up in parallel to get the desired positions using a single control switch. Let the electrical contacts of the switch points do the polarity flipping.
-- Don Vollrath (firstname.lastname@example.org), May 02, 2001.