Hello, I'm new to DCC, having run DC for almost 50 years. On a whim, I picked up two DCC with sound equipped diesel engines. It is my intention to run these two engines by themselves on my layout as I know my DC engines will be running nearly full throttle before the DCC engines think about starting. I have been running the DCC engines with my transistorized throttles for some time now, but as you all probably know, not all of the DCC features are available to me. So I picked up a NCE throttle system. My intention is to switch off my transistor throttles and switch on my NCE throttle using the same wiring that is presently being used on my layout, but with a few additions. Here is a sketch of my wiring on my present layout: See attachment titled: Throttle layout as built The layout is in a 12' x 24' room on shelves attached to the walls. There is an east bound loop and a west bound loop with crossovers. Here is a proposal for adding a DCC throttle to the layout: See attachment titled: Throttle layout with DCC throttle You will notice the addition of another switch to choose between a DC throttle or a DCC throttle. In operation, I propose that both DC throttles be turned off from the 120 volt supply. The DCC throttle be hooked to both dedicated rails(green and red) plus the orange common wire via the SPDT switches located throughout the layout. The purpose of this configuration would be for display purposes only for those viewing my layout. Over the years, I have acquired a rather large stable of DC engines and lighted passenger and caboose stock. I intend to never convert my layout to DCC. I have neither the resources or time to do it. So that is not an object of discussion. My question is simple. With all that I have shown and with you knowing my interests in DCC, would this wiring layout work? If not, why? To say it would not work without expressing the reason it would not work isn't an answer to me. I want to be shown/told the reason for it's not working. Thank You for your time. Doug Brown
It SHOULD work, but you need to be very careful that those DC throttles are disconnected. I would consider a DPDT switch, instead, which switches your common (orange) bus as well. Your other switches really become moot, since the DCC will run both directions just fine, but make sure you maintain polarity across your inner and outer loops.
Doug, I have done something similar, a switchover between DCC and DC, to use one or the other for running trains. I would add that the DPDT switch Rick is suggesting should be a Center Off DPDT. There is another descriptive name for these that escapes me, but the Center Off feature cuts power to one circuit before connecting power to the other one. Have fun!
MAKE SURE YOU USE THE DPDT SWITCH. Don't ask me how I know this. Never run a DC powered loco into a section where a DCC loco is running. Those who want to run two sections of the layout, one on DC and one on DCC have a completely dead section of rail between both parts of the layout. People who are savvy have no trouble doing this but those who do not, sometimes smoke the DCC controller. There are DPDT with no center off, either or situation. There are DPDT, Center Off. Read the details of the switch you are buying. Rich
An alternative to the DPDT switch is to use a plug and socket... mount a socket on your control panel where your DC controller used to be... a 2-pin mono phono (headphone or guitar) jack will work fine. Connect your green and orange wires to the socket. Then make up a cable each for your DC throttle and your DCC booster output that mate to the panel socket. When you want to convert one to the other, unplug and plug. Guaranteed no shorting that way. The switch is handy, though, if you don't want to fool with the cables.
I second that as it is unlikely to be accidentally operated. If you do use a switch put a cover over it - like those 'doom' switches Hollywood loves
