Great Scale Model Train Show Digital Command Control of Your Model Railroad Presented by Harford County Modular Railroad 1 Topics for Today What is Digital Command Control How DCC works (compared to DC) Advantages / Disadvantages Decoder features and installation Manufactures differences Demonstration layout set-up 2 What is Digital Command Control A control system using digital data packets to communicate commands to decoders that control the model railroad Huh? Packet = chunk of info (in zeros & one) Decoder = circuit that turns info into something the locomotive motor can use Like message sent to your email address All of the details are specified by NMRA standards for all manufactures 3 Introduction to DCC Page 1 of 6
How does DC control work? Conventional DC controls the voltage to the track then to the locomotive Steps are: House power to step-down transformer, To rectifier to change the AC to DC To speed control To direction control Send electricity from controller to track Thru wheels thru frame, thru wires DC turns the locomotive s motor 4 How does DCC control work? DCC sends signal through track to loco Steps are: House power to step-down transformer, Brain (command station) creates signal Electrical signal includes the speed, direction, and other instructions Signal is amplified (booster) Sent signal to the track Thru wheels via wires to decoder Decoder converts signal to DC for motor 5 Benefits of DCC Run your trains, not your track Electrical simplicity for basic system Can skip blocks, toggles, power routing Run your trains the way you want to run them High density action in mainline & yards Multiple locos controlled as a single unit Any direction at any time Prototypically with train orders or CTC 6 Introduction to DCC Page 2 of 6
Digital Benefits More accurate signal yields better throttle control (engines run better) Easier to upgrade system with new features / technology Power as the signal (if NMRA DCC) [compare to signal over power systems] NMRA DCC standard with competing manufactures and accessory makers 7 Disadvantages of DCC Cost of additional control electronics for small and medium systems Time or cost to electrically modify each engine (i.e. to install decoder) May need electrical changes when retrofitting existing layout 8 How DCC Works / Parts of a DCC System Power Supply (transformer) Command Station (computer brain) Booster (merges power & commands) Throttle (for engines & accessories) Decoder (translator of commands) 9 Introduction to DCC Page 3 of 6
How DCC Works / Electrical Specifics Track power is frequency modulated DC (square wave) Full power on the rails at all times (not variable DC as conventionally) Decoder (in locomotive or accessory) understands the modulated signals as commands to do something 10 Thinking of DCC System Purchase? Separate the important from the weeds Nothing on current market is bad What is right for you? DC, hybrid, DCC Local Hobby Store or Model RR Club A friend or club with DCC system Get the feel of various throttles 11 How DCC Works / Available Commercial Products Starter Sets MRC, Bachmann, Atlas (Lenz) & Digitrax Approaching plug and play Breakeven layout using 3-4 loco at once (even by price only, excluding features) Standard and Advanced Sets Differences in philosophy & style Features galore (almost beyond belief) Can get very complicated All have basic parts described above 12 Introduction to DCC Page 4 of 6
Manufactures Differences (examples) Polling versus Peer-to-Peer Network Limitations on addressing / address numbers and consisting Limitations on number of locomotives (usually this is amperage limited first) Throttle styles and features Nothing on current market is bad 13 Typical Decoder features (today) Programmable address to 9999 128 speed steps / speed tables Constant / directional lighting control Automatic analog conversion Acceleration / decel momentum Special effects generators for lights Base direction programming Transponding (in some decoders) Sound & more sound (some decoders) 14 Decoder Installation Already installed (perhaps change plug?) Plug and Play (PNP) using NMRA plug Conversion Harness (Athearn) Standard methods Electrically isolate motor Connect pickup leads to decoder harness Connect motor feeds Add lighting / light wiring Sound decoders need a speaker 15 Introduction to DCC Page 5 of 6
Additional Considerations Block wiring for Reversing sections Short circuit protection Power distribution Detection & signaling systems Programming track Computer control And now rapidly moving into large acreage of specialty minutia 16 Resources Printed Magazines Books Data sheets Internet Manufactures Dealers User Groups Private DCC Sites Live in person today: modular groups 17 Demonstration Many good brands available: track, controllers, and locomotives for today, we will use a: Set-up of Kato track, oval with siding Connection to Digitrax Zephyr system Acquire & operate several Bachmann Locos using Digitrax throttles 18 Introduction to DCC Page 6 of 6
Demonstration Illustrate these principles Relative ease of set-up and wiring High density action on mainline & siding Any loco in any direction at any time Multiple locos controlled as a single unit FUN Model Railroading is Fun Again, nothing in the current market is bad stuff Many vendors of DCC are here today 19 Black slide to end presentation 20 Introduction to DCC Page 7 of 6