Everything on model trains, model railroads, model railways, locomotives, model train layouts, scenery, wiring, DCC and more. Enjoy the world's best hobby... model railroading!
Everything on model trains, model railroads, model railways, locomotives, model train layouts, scenery, wiring, DCC and more. Enjoy the world's best hobby... model railroading!
It depends on the brand. the Peco one I have has 2 semicircular metal strips in the well with a sprung contact running to the rails on the table (One rail to one strip) so that when the table rotates it automatically keeps the correct polarity on the table’s track the same as the tracks leading to/from it. The Heljan table I have has 2 metal rings on the axle (one ring to one rail on the table) with wiper contacts from the power source. This needs a reversing switch incorporated into the operation as the table rotates 180 degrees it keeps the same polarity on the track on the table which will be the reverse of the polarity on the tracks leading to or from the table. Hope this explains it for you.
Ok, That’s interesting, thanks…
I have an Atlas Turntable. It is the same with the Atlas Turntable as in the Peco one. Each of the track outlets of the turntable is equipped with metal strips and as the table rotates it makes contact with the respective track outlet.
I use a separate controller which controls the turntable with dcc going into it through the rail and have no problems with it as long has each rail is wired the same coming of it it is a Hornby turntable.
For DCC sound locomotives, power needs to be constant to avoid the sound stuttering as the polarity is changed on the tracks – the split ring arrangement on the Peco turntable has a dead spot (which it needs to avoid the plungers being in contact with both halves of the ring at the same time) which momentarily cuts power to the locomotive. For DC, the split ring arrangement is better as it avoids the need for a DPDT switch to change the polarity.
If you want to use the Peco turntable with DCC sound fitted locomotives, it will need modifying to give constant power. There are plenty of sources of useful advice on how to do this online including this one:
https://www.dccinterface.com/how-to/peco-turntable-with-permanent-power-to-the-bridge-rails/
Finally, you need to connect the turntable bridge through a DCC reverse loop module to undertake the polarity switching and you’re sorted.
Very helpful, thanks all….