An idiot in search of DCC enlightenment...

[bnsf971]

Umm, one word or two of caution here. It is possible to run two locomotives into each other using DCC.

[Iron Horseman]

Originally Posted by Selector

DCC always supplies about 14 volts of square-wave AC current to all the rails ...

Just to be technically correct the voltage applied to the rails will vary from 13 to 17.5 VDCC depending on the system and system settings. My Lenz system from the factory was 17.5 VDCC. I found this was too high for my tastes and reprogrammed the unit to send 14.5 VDCC to the track.

[The_Limey]

Originally Posted by bnsf971

Umm, one word or two of caution here. It is possible to run two locomotives into each other using DCC.

LOL, already have a digital slotcar system so that's one thing I'm already wise to, but obviously that's all ready to run and there's no wiring - My bane!

[The_Limey]

Originally Posted by bnsf971

They don't HAVE to be all powered separately, but it will keep your trains running smoothly. The non-power routing option when selected supplies power at all times to the tracks. Power-routing will turn off power if a switch is thrown away from the part that has power.

Right... aha... so by selecting non-routing I am in effect making the whole thing live. therefore, if I just made sure that I run cables to extremes points etc?

[The_Limey]

Originally Posted by Selector

DCC always supplies about 14 volts of square-wave AC current to all the rails that are directly connected to each other and to the 'power distribution grid'. As in DC, where there are gapped and unpowered lengths, or where turnouts route power to one side of the frog and not the other when the points rails are lined appropriately, you will have dead rails there. If you still want power routing to avoid shorts at the frogs and guard rails (DCC systems are highly sensitive to shorting and will shut down), but if you also want the rails after the frogs powered, you will have to gap beyond the frog and power those rails with feeders.

The decoders adopt a name that you assign to them. Most of us use the 'cab number' on steamers or the diesel locomotive's individual number. The decoders run the locomotive, you run the decoders. If you want two engines doing two different things, you must direct each decoder to do what you want of it. They'll do it. So, you say you want to run two locomotives at once. Just acquire each cab number, one at a time, tell it do make the loco do something using your hand-held throttle, and then acquire the other and do the same. Both will continue to do what you assigned to them last until you command them to do otherwise.

There is a precis for wiring for DCC - http://www.wiringfordcc.com/

Thank you, most informative, but I have to say at 7:49 on a quiet U.K morning it caught me off guard

[bnsf971]

Originally Posted by The_Limey

Right... aha... so by selecting non-routing I am in effect making the whole thing live. therefore, if I just made sure that I run cables to extremes points etc?

Ye, on account of voltage drop over distance.

[The_Limey]

Thanks...

I'll run a feed to the two 'main lines and then into 2 or three of the sidings at each end then... That should do the trick I guess.

[Selector]

Originally Posted by Iron Horseman

Just to be technically correct the voltage applied to the rails will vary from 13 to 17.5 VDCC depending on the system and system settings. My Lenz system from the factory was 17.5 VDCC. I found this was too high for my tastes and reprogrammed the unit to send 14.5 VDCC to the track.

True, and it actually varies between 12 volts and on up into 24 volts, depending on the intended application and settings, as you suggest. In our case, with N scale, the decoders are required to be able to handle 24 volts DC per NMRA specifications, but they are meant to run typically at about 12 volts in that scale. I have run my HO decoders in all three voltage range settings with my Super Empire Builder's DB150 5 amp power...but not on purpose.

[diburning]

Just be careful and pick a number and stick with it. If your DCC voltage is too high, you can shorten the life span of your headlights or blow them out completely.

The club I belong to is mostly 14 volts, but there is a section where it is 16 volts. I use 16 volts in the resistance equation for all of my lighting installations to be safe.

I had a Kato RS2 that had a factory 12 volt bulb in the middle of the board. The bulb got so hot on 14 volts that it melted a hole in the roof of the loco.

[The_Limey]

Noted, thank you...

Mark



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