DCC decoder tester project.

[VA3TOM]

I wanted to find a better way to test the decoders. I wasn't fond of trying to alligator clip the wires to the track feed, and twist the wires to the LT1 tester. I went to Radio Shack and picked up a small project box and a 4 terminal speaker quick connect. I had a few DPDT toggles laying around. The only reason I needed toggles was so I can switch the LT1 from Track Test Mode to Decoder Test Mode. If you just want a decoder tester, you could wire the track feed wires straight to the two terminals of the speaker connect (with the resistor in line), and wire the LT1 to the other two terminals and save the box and toggles.

Here is the complete project;

Here it is with a decoder wired in and in test mode;

This keeps the wires from touching and cleans up the loose parts!
I still have some issues with the type of coating on these decoder wires though. I seem to have a tough time stripping the wire.

Tom

 

[Cjcrescent]

Thats neat!

One of the "commercial" testors I've seen, (by a dealer at the old GATS), breadboarded a motor into the circuit where the resitor went, and had it set up similiar to yours.

Always wanted to build one but haven't yet.

 

[UP2CSX]

Great idea! Time for a trip to Radio Shack to look for some switches I need so I'll pick up one of the speaker quick disconnects.

 

[Alcomotive]

Very cool! Do you have a schematic plan to show? I have the LT1 module but have not used it due the cumbersome method...but your idea is fantastic!

thx
Alco

 

[VA3TOM]

Took a bit, but here it is!

Wiring the Decoder Tester.

I put alligator clips on the ends of the wire for Track Feed. The track feed wire goes to the center part of the first DPDT toggle. With BOTH toggles in the Up position (or down, doesn't matter) the toggle connects the RED track feed directly to the BLUE LT 1 and the BLACK track feed to the WHITE LT 1. The second DPDT will connect the BLACK / BLUE wires and the WHITE / YELLOW wires to put the LT 1 in Track Test Mode.

Throwing BOTH toggles to the opposite position connects the RED track power through the resistor to the RED mobile decoder wire. The BLACK track wire goes to the BLACK decoder wire. The GRAY from the decoder goes to the GREEN wire on the other DPDT, and the ORANGE decoder wire goes to the RED wire. With the toggle thrown, the BLACK / GREEN wires and the YELLOW / RED wires of the testor are connected. The LT 1 is now in Decoder Test Mode.

I hope this helps anyone trying the project out. Let me know if there is any more info I can provide.

Tom