dcc in tomix shinkansen with power couplers

[keitaro]

So I was having a discussion with The Ghan about this and dcc and it was suggested you may need to isolate the front and rear car for the decoder in each car to control directional lights.


Can anyone confirm if this needs to be done. I have my doubts as the decoder would be picking up the current shared by all cars and the decoder would then control the current to the directional lights to make them function.

[KenS]

I'm not familiar with the way Tomix wires its cars, but I'd expect the wire from the trucks to essentially be an extension of the right and left rails.  As long as the lights connect to the decoder, and the decoder to that extension, then there's no reason to isolate one car from another.  Having two decoders in the train is electrically equivalent to having two trains with decoders on the rails.

I don't know what The Ghan was suggesting, but I think it must have been something else.

[Martijn Meerts]

There's no need to isolate the cab cars. Just install a separate decoder in them just like any other cab car, and you're all set.

[The_Ghan]

Yuh,

I did suggest that ... but logically it doesn't make sense.  The whole consist can remain properly connected and all three decoders wired to the pickups.  Lord only knows what I was thinking when I put it to Keitaro!!!  Sorry for the confusion.

Cheers

The_Ghan

[Martijn Meerts]

I'm pretty sure, somewhere on the internet, there's a site which claims you need to isolate the cab cars because otherwise there's a short circuit which will cause a rabbit to spontaneously combust on the other side of the world...

[inobu]

With DC everything is tapped off rail power which typically is the motor and lights. When converting to DCC everything utilizing rail power must be migrated to a DC output from a decoder of some sort.

The point may have been that the lights in the passenger cars (If any) must be isolated. The directional lights are isolated from rail power in the cab and connected to the decoders directional lighting ports. The next question is are there lighting boards in the passenger car as the coupler power feed runs through the whole length of the consist and those boards may cause a problem. 

That may have been the warning.

Inobu

[keitaro]

I'm pretty sure, somewhere on the internet, there's a site which claims you need to isolate the cab cars because otherwise there's a short circuit which will cause a rabbit to spontaneously combust on the other side of the world...

i wouldn't want to risk combusting a forum members rabbit.

Could be worse maybe it will spontaneously combust some one elses model train.