Wiring for both DC and DCC

[Anonymous]

TextI have read in several articles in Model Railroader about layouts being wired for both DC and DCC operation, but have not been able to find any detailed explanations for how this is done. Does anybody know how it's done or where I can find this information out?

[Anonymous]

I believe the only way to do it is to have two separate 'layouts' in one, one running DCC and the other DC. You can't run both DCC and DC on the same track, though the vast majority of DCC systems do support the special '00' address that lets you run one DC engine on the DCC track.

[cacole]

I wired the Cochise & Western Model Railroad Club's 20x40 foot HO scale layout that way.

We use one large, central power supply with an output of 19 Volts filtered DC at 40 Amps for both modes of operation. A DPDT toggle switch on the main power supply's control panel routes power from this supply to either the 10 DC block control throttles or the DCC boosters.

Two position, 6 pole rotary switches on the block control panels are turned to either the "Block Control" or "DCC" position to route the power from either the Cooler Crawler transistorized throttle circuit boards or the DCC system, through the block toggle switches, to the track.

To switch from one mode of control to the other, these rotary switches are changed to the desired position, and the power supply's toggle switch is changed to route power accordingly.

We have used this system for over 5 years now with no problems.

In answer to your basic question, however, I don't know of any wiring schematic for this -- I did it based on my own electronics background and experience.

[MisterBeasley]

I was thinking of doing something like that, but then I actually bought a DCC system. Half an hour after installing my first decoder, I disconnected the DC lines from the old power supply, and never looked back. I'd suggest you do the same. DCC is just so much better.

I have a bunch of old locomotives, so I was going to run DC for a while while I slowly got decoders in them. This turned out to be a poor strategy. First of all, old locomotives have no need for sophisticated decoders, so all that's needed is a basic decoder that goes for under $20 MSRP. I can equip the whole fleet for less than I spent for lumber and foam. Second, my old engines just aren't going to cut it. The motors are old, the wheels are old, the electrical pickups are bad, the headlights don't work and the detailing is terrible.

[Anonymous]

It might be helpful to envision a dual DC/DCC layout as being wired like a traditional two cab (Cab A, Cab B) DC layout, except that you're selecting DC or DCC instead of Cab A or Cab B for individual blocks.

That, I believe, is essentially what cacole is describing, though on his club layout it's more elaborate than might be needed for a small home layout.

I sometimes have the need to switch to one or the other to test something at home, but I simply swithch the whole layout. I have one set of master feeder wires to the track bus. It's either all DC or all DCC.

Mike Tennent

[rrinker]

Actually, it sounds as if cacole's system only allows one system to be active at a time (that master toggle switch on the central power supply). Which is the RIGHT way to do it, because inevitably someone will try to run their train past the block boundary gaps, and if one block is set to DC and the other to DCC, Bad Things can happen, to the loco itself, the decoder if it's a DCC loco that crosses the line, the DCC booster, or the DC power pack if it's a transistorized type.
It works, as long as you are extremely careful. It's also possible to wire it so that can't happen, but if you go through all that trouble you might as well just install decoders and forget the whole DC thing.

--Randy

[dacort]

I had already wired my layout for dual cab control when I got my DCC system, so I just hooked the DCC track outputs in place of cab "A". I still have my control panels with toggles, but they're almost always all set to "A", DCC. I only use DC now to test or break in locomotives that don't have decoders.

If I was going to build a new layout I probably would simplify the wiring and make it a pure DCC layout.