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I recently took the dive into DCC with the NCE Power Cab, but I would like to alternate between DC and DCC for a while, as suggested here. I wouldn't be running both DC and DCC simultaneously, but I would like to operate a session in DC, and another session in DCC. I'm not talking about running a DC loco on DCC.
I have 2 separate DC blocks, each controlled with it's own cab right now, and I'd like to know the best way to wire in the NCE Power Panel in such a way that the components on the panel don't get fried when I run my DC cabs. Obviously, I'd have the Power Cab disconnected when running a DC session.
My somewhat limited knowledge of electronics tells me I need something crazy like a 4 pole, single throw switch to alternate between these two configurations to ensure that the two circuits are joined together in DCC mode, and then maintain 2 distinct circuits when in DC mode.
Does anyone have further insight into what I should do?
I'm doing the same thing with DPDT center off switches. DC one way and DCC the other way, center off is my security. I still have to pay attention but I am getting better at it. I have multiple blocks to control.
...My somewhat limited knowledge of electronics tells me I need something crazy like a 4 pole, single throw switch to alternate between these two configurations to ensure that the two circuits are joined together in DCC mode, and then maintain 2 distinct circuits when in DC mode...
Close! You would need a 4 pole double throw (4PDT) switch. It would have three rows of four connections.
Your two wires from the DCC command station are DCCA and DCCB. Your two wires from cab 1 are C1A and C1B and cab 2 are C2A and C2B. Block wires are B1A, B1B, B2A, B2B:
This is what the Youth in Model Railroad group does. Each track (two independent loops) has a standard Telephone Jack plug. When it is a certain child's time slot to run they plug in the power system they desire to use onto the track they are assigned. Works great. Plus any one of the children can bring in their own command system to use. They just have to configure it with a similar plug.
Pretty similar to the 4 pole, but I use rotary switches for my blocks. I run 4 powerpacks in DC and now a DCC system. Position 1 on the rotary is not wired, so it becomes OFF, 2 thru 5 are the DC packs and position 6 is DCC. So in theory I can run 4 blocks in DC and a 5th in DCC, but like you, I only run one or the other. I got the rotary switches at the local Radio Shack.
Electricity works thru completed circuits. You can still have a common ground on one rail and be switchable between the other rail as DC/DCC as long as your circuits are separated. Tie one side of your DCC to the ground and put your DC on that ground as well, THEN wire your switch (SPDT) for dcc/dcc. If you use mulitple dc throttles you can use simple rotary switches to select throttle 1/2/3/4/dcc whatever. that what I planned, then I decided...MEH, go full DCC. I don't want spaghetti wire anymore.
this is if you want to block both rails switching out the power on both which is NOT required. You are overwiring. Reverse loops/Wyes do need that but can still maintain the common rail circuitry. Signal circuits need common rail wiring and you could even run a 3rd power circuit for the signals (if you should get into that) and everything else still functions. DC and DCC are on separate power circuits, even on multiple DC power supplies you can run common rail/common ground, you can throw dcc into the mix you will still be fine. Like I said, each system works only thru its own completed circuit. Thats simple electrical theory. You could use a single pole double throw (whichever it is thats 3 connections) or a rotary, 6 positions 1 pole if you must... Your track blocks at turnouts are still your basic trackwork blocking electrically, thats a must DC or DCC.
