Switch Decoder - Jack Wabbit DCC Specialties

[inobu]

This is a really good decoder in that it has a lot of the supporting components built in. This decoder can run 4 Tortoise or snap switches, it has LED signaling drivers built in ready to run. It program routes and has a model that supports Digitrax's Loco Net. I have a project that requires 11 of these so there is a lot of programming involved. Because these are pretty good decoders and I think I'll start using them I built a test board for it.

 

Instead of going into the details I'll just post the image an point out the general area and what they do.

For the most part the LED need limiting resistors but one section has a 5v output.  

 

 

Top Connection

 

The top gray wire is the Digitrax Loco Net connection. It allows for the monitoring and communication to the Loco Net bus to the

DCC command station and computer interface if used. . 

 

 

Right Side Bread Board

 

This supports the manual throw out of the switches.

There are 3 leads. 1 common and 2 control.

You can use momentary tactile or toggle switches 

The wires are banded for A-D switch controls (Same color code through out the test board)

A- Yellow

B- Blue

C- Green

D- Red

 

Lower Right

 

This is the power input

It can use a AC or DC connection. 9 to 20V. In this test case I'm using the output from the command station or rail power. Under

operation circumstances I would use an external power connection.

 

Left Breadboard (Lower area)

 

This is a 12 pin connector that drives the switch. In this case there's a 13 volt output using pins

1 and 3 - A

4 and 6 - B

7 and 9 -C

10 and 12 -D

The pins revers polarity to drive the switches.    

 

CV 79 will set the board to operate a Tortoise or Coil type switch (0 = continuous 1- Pulse on)

Wiring a bi-color LED with resistor or 2 single color LED for local signaling is easy for the continuous setting. The snap configuration will use

the next connector.

 

Left Breadboard (Upper Left) 

 

This is the feedback section. It provides the status of the turnout. If can be used as a general indicator or specific conditions.

Specific Conditions is either Clear or thrown. This allows for a visual indicator as well as a means to update the computer is connected.

The manual switch can be operated without the computer seeing it. This causes a problem as the switches state can be lost. The remedy is to

provide an interface that will update the computer to any activity. A NCE  AIU or Lenz LR101 will send the update to the computer.

 

This wiring can be a bit confusing.

 

The Feedback LED's has four +5V leads and four return leads. 1-4 +5V for switch A-D and 9-12 for the return for A-D respectively. we will look

at switch A only as the other switch connections will fall in place.

 

Switch A +5V is representing by the white wire on Pin 1. The return is represented by the gray wire on pin 9 on the Feedback LED;s connector.

 

On the Feedback Network Connector switch A is represented by pins 1,2,and 3. Pin 1 (Yellow) is the Clear indicator and pin 3 (Black) is the thrown.

pin 2 is the common pin.

 

Trace the wiring

 

To illuminate a LED we need to connect the +5V to the return. Because we have 1 switch that need to reflect 2 conditions we need to split the control.

Here's how its done. The return (Gray wire) Feedback LED pin #1 is connected to Network Feedback pin #2. The Network Feedback connector has 2 pins

that represents switch A. Pin 1 (Yellow) and Pin 3 (Black). Pin 1 will represent the Clear condition a Green LED and Pin 3 will represent a Red LED or Thrown condition.

 

Lighting it Up

 

If Switch A is Clear then +5V is on the white wire on Feedback LED pin 1. It is connected to the Breadboard at the top left. that is connected to Long leg of the LED (Anode). Note: there are 2 LED's with their anode connected to the same white wire.  Because we are tracing the (Clear) we will follow the Yellow wire. The Yellow wire is connected to pin 1. We can see that pin 1 goes to a "relay" (White component on board) that will connect it to pin 2 which is the gray wire that connects back to the Feedback LED's pin 9 completing the circuit and illuminating the LED. 

If Switch A is thrown that relay will switch to pin 3 (black wire) and the other LED will illuminate representing the Thrown condition. 

 

With this understanding you can either move the wire to a LED on the layout to represent the signal dwarf or wire it to a control panel. I think the added LED drivers makes it easier and faster to incorporate LED onto the layout. By grouping the wire and color coding you can get the job done in a flash.

 

Inobu

 

 

Note: It may seem that I'm all over the place with my posting as I posted airbrush and LED's and whatever else within a small window of time. It's because I do things in a Project Manage approach. I rotate through the projects as they cycle around I may post my findings. As thing come up I may add them to the rotation. When I get to a certain point I may post my findings but afterwards its move on. In any my intent is to help and inform on some of the things I find and hopefully it helps others. 

 

 

 

 

 

 

[inobu]

VERSION 1.0

 

[NXCALE]

I am not into DCC but interesting stuff.