81F Posted August 12, 2012 Share Posted August 12, 2012 Was just programming a newly DCC fitted loco using my elite when everything on the layout burst into life and started to run at full speed. Fortunately I was able to hit the emergency stop before desaster struck. However, afterwards I noticed a short. This was traced to one of my Granges and has only been fixed by changing its chip. Link to comment Share on other sites More sharing options...
poliss Posted August 12, 2012 Share Posted August 12, 2012 The short must have sent a scrambled 'signal' to all the decoders telling them to go at full speed. Were you programming your loco on an isolared section of track 81F? Link to comment Share on other sites More sharing options...
Fishmanoz Posted August 12, 2012 Share Posted August 12, 2012 Turning off DC operation should stop this happening again. The interrupted signal with the short occurring fools the decoder into thinking it is seeing DC not a DCC signal. Link to comment Share on other sites More sharing options...
Flashbang Posted August 13, 2012 Share Posted August 13, 2012 Hi Turning off dc operation IN EACH LOCOS DECODER Link to comment Share on other sites More sharing options...
Flashbang Posted August 13, 2012 Share Posted August 13, 2012 Hi Sorry for some reason my post posted itself!!! (Guess I hit a wrong key!) What I was trying to say is.... Each locos decoder will need its dc operation turned off. If you use a DCC Bus pair of wires consider fitting DCC Filer units to all ends of tghe bus wires. These will remove spikes on the DCC signal caused by shorts etc and should prevent runaways occurring. Filters can be purchased ready made or for less than a £1 (One GBP) each be made up yourself from two simple components. Details of make your own filters can be found here... http://www.brian-lambert.co.uk/DCC.htm#Basics Scroll down to the sub heading "On very long bus wire runs or where poor DCC performance is noted" Ready made filters example... http://www.ebay.co.uk/itm/DCC-bus-terminator-X-2-NCE-ECOS-HORNBY-etc-/271025309017 Link to comment Share on other sites More sharing options...
Flashbang Posted August 13, 2012 Share Posted August 13, 2012 I have just sent a reply but the Hornby Forum system believes it needs Moderation due to an ebay hyper link!!! Basically I have said... Sorry for the above post which for some reason seemed to post itself before I was ready! You need to turn off dc operation is each locos decoder. Alternatively, if you use a DCC bus pair of wires to feed your rails etc then consider adding a DCC Terminator filter to each end of the bus wires. These filters will help remove the spikes on the DCC system often caused by a short circuit and help smooth any other poor quality DCC signals. You can make your own filters from two simple components for less than a £1 per unit or buy them ready made. That's where the ebay link came in! Making your own filters are shown on this web site.. http://www.brian-lambert.co.uk/DCC.htm#Basics Scroll down to the item sub headed "On very long bus wire runs or where poor DCC performance is noted a 'Bus Terminator filter' circuit may help stabilise the data signals flowing in the DCC Bus wires." Link to comment Share on other sites More sharing options...
81F Posted August 15, 2012 Author Share Posted August 15, 2012 poliss said: The short must have sent a scrambled 'signal' to all the decoders telling them to go at full speed. Were you programming your loco on an isolared section of track 81F?Yes Link to comment Share on other sites More sharing options...
81F Posted August 15, 2012 Author Share Posted August 15, 2012 81F said: poliss said: The short must have sent a scrambled 'signal' to all the decoders telling them to go at full speed. Were you programming your loco on an isolared section of track 81F?Yes Just to clarify the Grange causing the short was not the loco I was programming - just a loco sat on the furthest most inaccessable points on my layout! In the future I will probably unplug the elite from the bus as this will be a lot easier than the other options. However, eliminating spikes may be usefull. Link to comment Share on other sites More sharing options...
poliss Posted August 15, 2012 Share Posted August 15, 2012 Did you remove the leads from the track output? Link to comment Share on other sites More sharing options...
poliss Posted August 15, 2012 Share Posted August 15, 2012 Answered my question as I was asking it. lol Link to comment Share on other sites More sharing options...
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