DCC and a turntable

[ClintOHenry]

I want to install an old turntable. I have been careful to wire my layout one rail to my red buss and the other to my black buss. How do I handle the polarity when the loco is turned 180 deg. on it? Can I use a double pole double throw and manually change it before I drive the loco off after "spinning" it?

 

[dinwitty]

thats usually the trick

 

[Selector]

If the TT has a split rail design, you don't need to worry about it. The split rail design reverses the polarity automatically. Otherwise, yes, you'll need either a DPDT or an automatic reverser such as the PSX-AR.

 

[waltr]

If not a 'split rial' power feed you can use an Auto-reversing module. I use a Dual Frog juicer setup for auto-reverse on my turn-table.
http://www.tamvalleydepot.com/support/frogjuicers.html

 

[Iron Horseman]

Yup three things that need DCC auto reversing units. Reverse Loops, Wyes, and Turntables, or you can use the good old manual DPDT switch. As the others have said the newer turntables are wired internally to reverse the power so if you have one of those you might not need to do anything.