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NOTE This Clinic Is Highly Animated With Picture Overlays And Graphics. PDF and Other Versions May Look Contaminated. AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 2
AC-DC-DCC By Dr. Gerry Albers NMRA Life Member Cincinnati Div. 7, MCR With Examples from the Author s Deepwater District, Virginian Railway Photo credits: Gerry Albers, Clinician AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 3
Deepwater District - Virginian Railway Deepwater District New River Division Virginian Railway 1600 Sq. Ft. 11 Hidden Staging Yards 49 Staging Tracks AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 4
Introduction (Stuff I Wish Someone Had Told Me) AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 5
Overview DC (Batteries) DC From AC Half Wave, Full Wave Unfiltered, Filtered DCC (A Square Form of AC) DCC Layout Wiring Preparing For Signals Device Hierarchy, System Architectures Detector Wiring, Characteristics Switch Wiring Multiple DCC Track Buses Neat (Cool/Tidy) Wiring Practices Color Codes, Wires Sizes IDC Connectors Strap Gun Usage Miscellaneous Stuff DCC Cab Buses The Differences Master/Slave vs. Peer-to-Peer Take Aways : Practical Information and Useful Tips Vendor Independent AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 6
DC From Batteries Purest Form Bagdad Battery probably the first. Used for electroplating gold onto silver objects (~ 200 BC 200 AD). Voltaic pile invented by the Italian physicist Alessandro Volta in 1800. Battery coined by Benjamin Franklin for an arrangement of multiple Leyden jars. Railroads used batteries for telegraph and signals. Modern hybrid locomotives employ large arrays of batteries Model Railroad Uses E.G., Wireless Throttles Nickel Metal Hydride (NiMH) Rechargeable Bagdad Battery NASA Publication Symbol AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 7
AC Basics V R 15.8V = I =.016 A 1000 Oscilloscope Trace 15.8VDC 15.8 VAC RMS For a Transformer: The rated voltage is only valid at the rated current. 120 VAC 60 Hertz 14 VAC @1.14A 1000 Ohms GND 22.3 Volts Peak 44.6 Volts Peak-to-Peak 15.8 Volts AC RMS* 0 V DC 16.6 milliseconds per cycle DMM (Meter) 60 Hertz (cycles per second) (1/.0166 = 60) Clock Timing *RMS: Route Mean Square (Square root of the mean of the sum of the squares) Also known as Effective Voltage RMS = 0.707 * Peak (for sinusoidal waveforms only) IN Measuring Device* * Digital Multi-Meter (DMM) or Oscilloscope AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 8
Half Wave DC 0.7V + IN Oscilloscope Trace 120 VAC 14 VAC @1.14A 1000 Ohms GND 21.6 Volts Peak (22.3V - 0.7V) 8.3 Volts AC RMS 6.7 Volts DC DMM (Meter) Cathode Diode + Anode A Diode (Half Wave Rectifier): Increases the DC component Decreases AC component Light Emitting Diodes (LED) Produce Light AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 9
Full Wave DC 14 VAC @1.14A AC + Bridge Rectifier IN Oscilloscope Trace AC 1000 Ohms 20.9 Volts Peak (22.3V 1.4V) 6.8 Volts AC RMS 13.0 Volts DC GND DMM (Meter) A Full Wave Rectifier: Increases the DC component Decreases the AC component AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 10
Full Wave, Filtered DC AC Oscilloscope Trace 14 VAC @1.14A AC + 1000 Ohms IN 10 µf GND 20.9 Volts Peak (22.3V 1.4V) 2.6 Volts AC RMS 17.2 Volts DC DMM (Meter) A Filter Capacitor: Increases the DC component Decreases AC component AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 11
AC vs. DCC Oscilloscope Trace AC Oscilloscope Trace DCC 1 0 ~14V (14 VAC) 1/60 Sec. NMRA RP9.2 AC provides: Power Accurate Timing (60 Hertz) DCC provides: Power (Square AC) Information (1 s & 0 s) Use AC Setting on DMM AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 12
Power Hierarchy Home Wiring Analogy Transformer Circuit Breaker/ Disconnect CB Panel ~7,500V Circuit Breaker- Disconnect 120/240V 200A 120/240V Ground Fault Outlet (GFCI) 120V 20A Similar To DCC Booster Similar To Power District Circuit Breakers AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 13
DCC Device Hierarchy AC-DC-DCC T T T Cab Bus (or LocoNet) Throttles (Cabs) Fan (12VDC) Power District Definition DCC Circuit Breaker(S) P1A Fan (12VDC) DCC Circuit Breaker(S) P1B As Many As Needed P1 DCC Booster & CB Track Bus (DCC) DCC Circuit Breaker(S) P1C DCC Circuit Breaker(S) P1D Only One Power Supply DCC Command Station Ground! (Consult Manual) Power Supply Control Bus (or LocoNet) Fan (12VDC) MCM Electronics Switch Both Rails P2 DCC Booster & CB 5 Amp Keep Same Polarity Power Supply 8 Amp Booster Near Track Magna Force MF615 Power Supply > Booster Gap Both Rails AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 14
DCC Track Wiring Track Feeders, 20 ga. solid AC-DC-DCC DCC Rail A (12 ga. stranded) 3M Scotchlok 567 (All 12/20 ga.) (Double 20 ga.) DCC Rail B (12 ga. stranded) Simple (Undetected) DCC Wiring Wire color avoids NEC standards (12 and 14 gauge) 12 ga. stranded for Track (DCC Power) Bus (not Block Bus more later) DO NOT TWIST. Maintain ~1 inch separation 20 ga. solid for Track Feeder One pair of feeders for every section of track DO NOT TRUST RAIL JOINERS (OR SWITCH POINTS) FOR ELECTRICAL CONTACT Nickel-silver rail is a poor conductor compared to copper. All connections made with IDC s (Insulation Displacement Connectors) NO SOLDERING UNDER THE LAYOUT!!!!! Use appropriate IDC for wire sizes AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 15
Detector Characteristics: AC-DC-DCC Determine the occupancy of a block or specific location. Types Current Detector (requires conduction thru motor, light, resistor, etc) Position Detector (light beam, magnetic, contact, weight) Uses Automatic Signal Systems Centralized Train Control (CTC) Grade Crossing Protection Automatic Turnout Actuation Design Criteria Sensitivity» Detect decoder only» Adjustable False Positive Indication» 1 second turn-on delay False Dropout» 3 to 5 second dropout Isolated from DCC Track Bus Distributed not centralized Cardstock Placard 14 AWG Block Wire Team Digital DBD2 (DBD22 ) To Block Bus From Track Bus Current Detector To Block Bus AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 16 Power To Signal Logic (Computer)
DCC Detector Wiring AC-DC-DCC Block Feeders, 14 ga stranded DCC Rail A (12 ga. stranded) 3M Scotchlok 562 (All 12/12ga. & 12/14 ga.) Block 1 Current Detector Block 2 Current Detector Block 3 Current Detector Block 1 (14 ga. stranded) Block 2 (14 ga. stranded) Block 3 (14 ga. stranded) 3M Scotchlok 567 (All 14/14 ga. & 14/20 ga.) Block 1 Block 2 Block 3 DCC Rail B (12 ga. stranded) DCC Wiring With Current Detection Detected rail (Rail A or Rail B) has its own Block Bus (14 ga. stranded) Gap only detected rail Opposite rail becomes common rail All connections made with IDC s (Insulation Displacement Connectors) NO SOLDERING UNDER THE LAYOUT!!!!! Use appropriate IDC for wire sizes Detector must be on Block Feeder NOT ON BLOCK BUS AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 17
DCC Switch (Turnout) Wiring Block Feeder DCC Rail A Block X Current Detector Block X Tillig DCC Friendly Turnout DCC Rail B Tortoise Switch Point Power - Contacts on Tortoise) (Not needed with DCC-friendly Switches) Power frog and switch points (or use DCC-Friendly Switches) DO NOT TRUST SWITCH POINTS FOR ELECTRICAL CONTACT Switch is part of Block X AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 18
DCC Layout Wiring Multiple DCC Buses DCC Rail A XDCC Ckt. Breaker 20 ma. Accessory Decoder 17 ma. Tortoise Stalled Motor Locomotive is and dead. Decoder Accessory is powered. Decoder are dead! DCC Rail A DCC Rail B DCC Ckt. Booster Breaker DCC Accessory Bus Tortoise 100 x.020 = 2.0 A Signals 100 x.010 = 1.0 A 3.0 A Accessories will draw ~5 times more current than trains. DCC Rail B A Separate DCC Accessory Bus Provides: Accessory Power independent of Track Power. Sufficient accessory power for many devices. AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 19
DCC Layout Wiring Multiple Buses (Continued) DCC Rail A DCC Ckt. Breaker DCC Rail B Accessory Decoder Tortoise DCC Rail A DCC Booster DCC Accessory Bus Lighting Camera DCC Rail B Computer Power Supply Accessory Decoder +12 VDC Monitor GND AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 20
DCC Layout Wiring 12V DC Bus Applications Camera & Monitor Lighting AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 21
Miscellaneous Stuff AC-DC-DCC IDC Connector PowerFast Strap Gun 12-14NM Detector AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 22
Miscellaneous Stuff Documentation!!!!! AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 23
Bus (Network) Architectures - General Point to Point (RS232) - 2 devices (e.g., teletypes) - Limited distance, ~10 ft. Hub S S M S Bus Network (RS485) - Multiple devices (32 to 256) - Expanded distances (~4000 ft) - Must be linear (cannot be treed ) - Usually Master/Slave, Polled - C/MRI, NCE (&other) Command Buses Ring Network - Continues to work if ring is broken - Usually large numbers of users Star (Ethernet, USB) - Fast (~100MB/S) - Most popular local area type - Requires Hub P P P P P P P Tree Network (LocoNet ) - Connections and routing not constrained - Slower transmission speeds - Peer-to-Peer, Event-Driven AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 24
DCC Architectures (Digitrax vs. Others) A A L L A A L L Track Bus (DCC Commands) Optional B B NMRA RP9.2 Track Bus Combined T CS/B B Optional Control Bus (DCC Commands) Command Bus* (LocoNet) T CS Cab Bus (RS485) Most DCC Systems Cab Bus is RS485 (IEEE Standard) Command Station is Master Master must poll each device to transfer data Cycle repeated continuously (constant activity on Cab Bus) T May Be Combined No NMRA Standard Vendor Dependent B = Booster CS= Command Station I/O= Input/Output Device PC= Personal Computer T = Throttle A = Accessory (Switch) L = Locomotive Note: This diagram does not address transponding. T *Combines Cab and Control Buses Digitrax DCC System Peer-to-Peer relationship Distributed Intelligence all devices equal Event Driven (only changes transmitted) LocoNet allows device-todevice communication T AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 25
Suppliers Logic/Electronics See Handout Signals/Electronics See Handout Signal Operating Software See Handout Acknowledgements AC-DC-DCC Digitrax and LocoNet are registered trademarks of Digitrax Corporation NCE is a registered trademark of North Coast Engineering Corporation AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 26
The Deepwater District Construction Crew It s not the destination that s important, it s the journey (with friends). AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 27
STOP! (Then Proceed) Standby For: Signals By Spreadsheet Thank you for your interest and attention! AC-DC-DCC4_blue.ppt x 8/1/2012 Slide 28
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