2. NOTE This Clinic Is Highly Animated With Picture Overlays And Graphics
NOTE This Clinic Is Highly Animated With Picture Overlays And Graphics. PDF and Other Versions May Look Contaminated.

3. By Dr. Gerry Albers NMRA Life Member Cincinnati Div. 7, MCR
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

4. Deepwater District - Virginian Railway
New River Division
Virginian Railway
1600 Sq. Ft.
11 Hidden Staging Yards
49 Staging Tracks

5. (Stuff I Wish Someone Had Told Me)
Introduction

6.  Preparing For Signals
Overview
DC (Batteries)
DC From AC
Half Wave, Full Wave
Unfiltered, Filtered
DCC (A Square Form of AC)
DCC Layout Wiring
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
Vendor Independent
 Preparing For Signals
“Take Aways”: Practical Information and Useful Tips

7. 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
Bagdad Battery
NASA Publication
Symbol
Nickel Metal Hydride (NiMH)
Rechargeable

8. * Digital Multi-Meter (DMM) or Oscilloscope
AC Basics
15.8V
1000
= I = .016 A V R
Oscilloscope Trace IN
Measuring
Device*
* Digital Multi-Meter (DMM) or Oscilloscope
120 VAC
60 Hertz
14 VAC
@1.14A
1000 Ohms
GND
15.8VDC VAC RMS
22.3 Volts Peak
44.6 Volts Peak-to-Peak
15.8 Volts AC RMS*
0 V DC
16.6 milliseconds per cycle
60 Hertz (cycles per second) (1/.0166 = 60)
DMM
(Meter)
 Clock Timing
For a Transformer:
The rated voltage is only valid at the rated current.
*RMS: “Route Mean Square” (Square root of the mean of the sum of the squares)
Also known as “Effective Voltage”
RMS = * Peak (for sinusoidal waveforms only)

9. Light Emitting Diodes (LED) Produce Light
Half Wave DC +
0.7V
Oscilloscope Trace IN
14 VAC
@1.14A
120 VAC
1000 Ohms
GND
21.6 Volts Peak (22.3V - 0.7V)
8.3 Volts AC RMS
6.7 Volts DC
DMM (Meter) +
Anode
Cathode
Diode
Light Emitting Diodes (LED) Produce Light
A Diode (Half Wave Rectifier):
Increases the DC component
Decreases AC component

10. Full Wave DC 20.9 Volts Peak (22.3V – 1.4V) 6.8 Volts AC RMS
Oscilloscope Trace AC
Bridge Rectifier
14 VAC
@1.14A + IN AC
1000
Ohms
GND
20.9 Volts Peak (22.3V – 1.4V)
6.8 Volts AC RMS
13.0 Volts DC
DMM (Meter)
A Full Wave Rectifier:
Increases the DC component
Decreases the AC component

11. Full Wave, Filtered DC 20.9 Volts Peak (22.3V – 1.4V) 2.6 Volts AC RMS
Oscilloscope Trace AC
14 VAC
@1.14A + IN AC
1000
Ohms
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

12. AC DCC AC vs. DCC AC provides: Power Accurate Timing (60 Hertz)
Oscilloscope Trace
Oscilloscope Trace
~14V
(14 VAC)
“1”
“0”
NMRA RP9.2
1/60 Sec.
AC provides:
Power
Accurate Timing (60 Hertz)
DCC provides:
Power (Square AC)
Information (1’s & 0’s)
Use “AC” Setting on DMM

13. Power Hierarchy – Home Wiring Analogy
Similar To DCC Booster
Circuit Breaker/
Disconnect
120/240V
200A
Transformer
CB Panel
120/240V
Similar To
Power District
Circuit Breakers
~7,500V
Circuit Breaker-
Disconnect
Ground Fault
Outlet
(GFCI)
120V
20A

14. Control Bus (or LocoNet) Power Supply > Booster
DCC Device Hierarchy
Cab Bus
(or LocoNet)
DCC
Command
Station
Throttles
(Cabs) T
Fan (12VDC)
Power
Supply
Keep Same Polarity
As Many As Needed
DCC
Booster
& CB
Control Bus (or LocoNet)
Only One
Booster Near Track P1 P2
Power
Supply
Ground!
(Consult Manual)
Power
District
Definition
Power
Supply
DCC
Circuit
Breaker(S)
Track Bus (DCC)
MCM
Electronics
5 Amp
8 Amp
Power Supply > Booster
Magna Force
MF615
P1D
P1C
P1B
P1A
Switch Both Rails
Gap Both Rails

15. DCC Track Wiring Simple (Undetected) DCC Wiring
DCC Rail A (12 ga. stranded)
DCC Rail B (12 ga. stranded)
Simple (Undetected) DCC Wiring
Track Feeders, 20 ga. solid
3M Scotchlok 567
(All 12/20 ga.)
(Double 20 ga.)
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

16. Detector Characteristics:
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
Current Detector
14 AWG
Block Wire
Cardstock
Placard
Team Digital
DBD2™
(DBD22™)
Power To
Signal Logic
(Computer)
From Track Bus
To Block Bus
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

17. DCC Detector Wiring DCC Wiring With Current Detection
DCC Rail A (12 ga. stranded)
DCC Rail B (12 ga. stranded)
Block 1 (14 ga. stranded)
Block 2 (14 ga. stranded)
Block 3 (14 ga. stranded)
Block 1 Current Detector
Block 2 Current Detector
Block 3 Current Detector
DCC Wiring With Current Detection
Block Feeders, 14 ga stranded
3M Scotchlok 567
(All 14/14 ga.
& 14/20 ga.)
3M Scotchlok 562
(All 12/12ga. & 12/14 ga.)
Block 1
Block 2
Block 3
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

18. DCC Switch (Turnout) Wiring
DCC Rail A
DCC Rail B
Block X
Block X Current Detector
Block Feeder
Tillig Turnout
DCC Friendly
Switch Point Power - Contacts on Tortoise)
(Not needed with DCC-friendly Switches)
Tortoise
Power frog and switch points (or use DCC-Friendly Switches)
DO NOT TRUST SWITCH POINTS FOR ELECTRICAL CONTACT
Switch is part of Block X

19. DCC Layout Wiring – Multiple DCC Buses
DCC Rail B
DCC Rail A
DCC
Ckt. Breaker X
Tortoise
Locomotive is dead.
Decoder is powered.
Locomotive and
Accessory Decoder
are dead!
Accessory
Decoder
DCC Rail B
DCC
Ckt. Breaker
DCC Rail A
DCC Accessory Bus
Stalled
Motor
DCC
Booster
17 ma.
20 ma.
Tortoise 100 x .020 = 2.0 A
Signals 100 x .010 = 1.0 A
3.0 A
A Separate DCC Accessory Bus Provides:
Accessory Power independent of Track Power.
Sufficient accessory power for many devices.
Accessories will draw ~5 times more current than trains.

20. DCC Layout Wiring – Multiple Buses (Continued)
DCC Rail B
DCC Rail A
DCC
Ckt. Breaker
Tortoise
DCC Rail B
DCC
Booster
DCC Rail A
DCC Accessory Bus
Accessory
Decoder
Accessory
Decoder
Camera
Lighting
Monitor
Computer
Power Supply
+12 VDC
GND

21. DCC Layout Wiring – 12V DC Bus Applications
Camera & Monitor
Lighting

22. 12VDC Bus Track Bus IDC Connector Block Buses Detector
Miscellaneous Stuff
12VDC Bus
Track Bus
IDC Connector
Block Buses
Detector
PowerFast
Strap Gun
12-14NM

23. Miscellaneous Stuff – Documentation !!!!!

24. Bus (Network) Architectures - General
Point to Point (RS232)
2 devices (e.g., teletypes)
- Limited distance, ~10 ft.
Hub
Star (Ethernet, USB)
Fast (~100MB/S)
Most popular local area type
Requires Hub S M
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
Tree Network (LocoNet®)
Connections and routing not constrained
Slower transmission speeds
Peer-to-Peer, Event-Driven P
Ring Network
Continues to work if ring is broken
Usually large numbers of users

25. DCC Architectures (Digitrax vs. Others)CS A B
Cab Bus (RS485) L
Control Bus (DCC Commands)
Track Bus (DCC Commands)
Optional
Most DCC Systems T
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)
NMRA
RP9.2
No NMRA
Standard
Vendor
Dependent B T
CS/B
Command Bus* (LocoNet)
Digitrax DCC System A L
Track Bus
Optional
*Combines Cab and Control Buses
Peer-to-Peer relationship
Distributed Intelligence – all devices equal
Event Driven (only changes transmitted)
LocoNet allows device-to-device communication
Combined
May Be
Combined
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.

26. Signal Operating Software
Suppliers
Logic/Electronics
See Handout
Signals/Electronics
Signal Operating Software
Acknowledgements
Digitrax and LocoNet are registered trademarks of Digitrax Corporation
NCE is a registered trademark of North Coast Engineering Corporation

27. The Deepwater District Construction Crew
Jim Hodde
Gerry Albers
Dave Read
Scott Firth (Deceased)
John Listermann
Bob Shreve
Paul Maciulewicz
Kevin Orcutt
Wes Reece
Allen McClelland
It’s not the destination that’s important,
it’s the journey (with friends).

28. STOP! (Then Proceed) Standby For: Signals By Spreadsheet
Thank you for your interest and attention!