wiring the Atlas turntable for DCC

I think you've already got the basic idea.  If you have a single lead track, note the "red side" and "black side" of the wires coming in.  If that's one of the "A" slots, wire all the other "A" tracks the same way, and wire the "B" slots the opposite way.  The internal guts of the turntable will take care of the rest.

You don't need any special circuitry or wiring for the stall tracks, just the right pair of wires to each.  But, I would recommend putting a toggle switch in one of the leads to each stall.  This will allow you to cut power to the stall track completely.  It's not that big a deal with non-sound engines, because having DCC allows you to have the engines sitting there without drawing significant power, but the sound engines will come on and both draw current and make noise whenever you power up your layout.  (Some sound engines have a "shutdown" sequence which powers them down, and they don't come up until the right "startup" keys are pressed, but other sound decoders will always restart on power up.)

 Unless they changed something, I don;t think the Atlas turntable uses a split ring pickup to automatically flipt he polarity. All of the Atlas layout books show hooking up the reverse loop DPDT switch on a Controller to the turntable track. The easiest solution for DCC is an auto-reverse unit, DCC power in to the autoreverser, the outputs connect to the turntable bridge power (and ONLY the bridge power). But a DPDT switch wired as a reversing switch (wires in an X on the corner terminals, DCC in to the middle terminals, wires to the turntable bridge to the terminals at one end of the toggle) will work too, and is cheaper. But you have to remember to flip the toggle and just when to do it. With the autoreverse yo just runt he train onto the table, spin to whichever track you want, or all the way around, and run the train off.

 

                                          --Randy

 

The Atlas turntable does use a split ring to power the table track, and it switches polarity at the point where the A and B tracks split, which should be directly across from the crank/motor position. That's why the tracks positions are labeled A and B. If you match the polarity correctly for DC, it will be right for DCC. I run DC with the Atlas turntable and matched the polarity of the approach track and all the storage tracks with the table track. This would probably be easiest to wire up as DC power supply with a DC locomotive, then once all tracks match properly for DC, just change the power supply to your DCC source. The main advantage of doing this with DC is a polarity mismatch is instantly seen with the locomotive trying to reverse.

My table and tracks do not have a separate reversing switch of any kind, so you shouldn't need a DPDT switch or a DCC reversing unit.

 

Rich

TomDiehl

My table and tracks do not have a separate reversing switch of any kind, so you shouldn't need a DPDT switch or a DCC reversing unit.

 

This is correct, nothing additional is needed for DCC for the Atlas TT.

An easy way to see if you've got it wired correctly, without risking the circuitry in any of your locos, is to use a multimeter set to AC voltage.  If you touch one probe to one rail of the turntable, and the other probe to the rail it lines up with, then the voltage should read exactly 0.  If it's anything else (usually around the 16V range), you've got it wrong.