My take on the matter is that the DCC system should power anything on the rails and anything that has to be connected to the rails (occupancy detectors.) All else should be powered by other, more suitable sources. Especially with two coil switch machines (Atlas, Rix, KTM/Kemtron...) using DCC for machine power is like using Perrier water to wash your driveway.
For my own switch machines (Rix and Katsumi) I built a dedicated power supply from a 12.6V 3 amp filament transformer. It powers the switch machines and a few indicator lamps - period.
For that matter, in places where the prototype would use manual switches I use manual throws - electrical switches mounted below track level in openings in the fascia, mechanically linked under the subgrade. Prototype engineers don't change point positions of minor turnouts by pushing buttons on their consoles. Ground men do it, with switch keys and muscle power.
Just my . Others are sure to disagree.
Chuck (Modeling Central Japan in September, 1964 - with 2-coil and manual point actuators)
In most cases, the DC-to-DCC conversion is as simple as "out with the old, in with the new," at least as far as the layout goes. Yes, you need to put decoders in your older engines, but that's also something you can do gradually. Most of us find that we do this a bit more quickly than planned, because it's just so much nicer to run on DCC, and each time we upgrade an old engine, it's like getting a new engine.
The only problem you might have with your DC layout is electrical connectivity. DCC is more fussy about good power distribution. Any flaky connections or dirty tracks will cause problems with DCC that you might have been able to ignore with DC. But, if your layout and engines were solid and reliable on DC, there's no reason that the "transition era" to DCC should be anything other than easy.
It takes an iron man to play with a toy iron horse.
Many thanks. I've delayed my move to a newer system until I'm comfortable with some of the details of the existing layout that might/or might not have to be changed. Last thing one wants is to find that a major renovation is required.
Mike
You can keep the old toy train power pack and leave all your turnouts just as they are. There is no requirement to run your turnouts through your DCC system. It's an available option with most systems, but many of us choose to run our turnouts just like before.
If you feel like using DCC for your turnouts, you can do it gradually, one turnout at a time.
I have several #4 and #6 Atlas switches operated by remote switch machines powered through a seperate bus connected to an old toy train power pack. Everything has worked well on my current MRC Command 2000 system, but if/when I upgrade will I have problems if the new system is DCC only?