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Digital/analog switchbox for Carrera Digital

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  • Digital/analog switchbox for Carrera Digital


    Last edited by 356speedster; 01-02-2012, 10:43 AM.

  • #2
    Cool looking setup, I see you use separate analog controllers, how is it connected ? Don't do what I did and fry your pit lane leaving it connected during analog use..
    Last edited by Burtonbr; 12-31-2011, 10:27 AM.


    • #3

      I took a spare BB and removed the circuit board to make an "analog box" that switch between digital or analog mode and has connections for analog controllers and power.

      On the left side I plug in the cable from the BB (see explanation below) and on the right side I plug in power for analog use.

      The wiring is basically done using three "4-pole dual throw" switches

      Top left: Switch between digital/off/analog
      Top right: Left/right direction for analog mode
      Right side (behind analog power plug): Polarity switch for analog mode

      The polarity switch is not really needed, but I added it since I have some analog controllers that need different polarity.

      On the front are the two XLR connections for analog controllers. Later I plan to add brake switches for the analog controllers and some LED's that show which mode the track is in.

      Here is the underside of the "analog box", not much to see other than the wire spaghetti, but you might notice that this is now the main connection track for both digital and analog.

      The BB needs to be modified slightly to work with the analog box. Below is the standard BB wiring:

      and here is the modified BB with the new plug that plugs into the analog box.

      Wiring up the analog box took a lot of time and pondering to get it right, while modifying the BB takes 5 minutes, so having all the "difficult" wiring in it's own connection track made sense to me since I plan to change the layout a couple more times and also have a CU on it's way.

      It's sweet to able to swap between digital and analog with a switch and not have to worry about what is connected where

      BTW: Thanks for the reminder on the pitlane. I have it on order and are looking into how to customize it to work safely when in analog mode. I have already modified the LC's for analog use with anti-collision chips, and that works great.

      Last edited by 356speedster; 01-01-2012, 04:09 PM.


      • #4
        IMPORTANT: Opening up your Carrera digital track pieces (BB/CU/LC's etc..) will void the warranty, if you wish to try the custom wiring it is at your own risk

        For those of you willing to risk damaging your track, accessories, controllers and powersupply, I'll try to document the wiring for the analog box before I forget it

        To change the track between digital and analog operation, you basically just need one switch wired in between the BB/CU and the track rails. You need a 4-pole double throw (4PDT) switch with "on/off/on" function that is rated for 5-6 amps or more.

        This is how I wired it:

        Notice that when I wrote "Analog controller" I meant "from Analog controller hookup panel". How you wire your hookup panels (negative or positive) only affects which direction the track runs in analog mode, which is why a direction switch on the hookup panel is very convenient because then you don't have to worry about the direction

        Also Notice that Carrera Digital use red wires for positive (+) and black wires for ground (-), this is very logical to me so I use the same color coding on the diagram above to make sure the polarity of the track connections is identical with Carrera Digital wiring.

        The confusion emerge when you look at the USA standard for positive wired hookup panels, where positive (+) is marked by black wires and ground (-) is marked with red wires. I have no idea why it is that way, but it just is, so to avoid confusing myself and others I use different colors and the terms "motor" (+) and Ground (-) for the analog side of the wiring scheme.

        I'll try to draw up the analog wiring later.

        Last edited by 356speedster; 01-02-2012, 10:26 AM.


        • #5
          This is very helpful Tore, at least for me because I was going to do this in my D143 to be able to race the 143 analog and the coming Dslot 1/43 cars.

          On D143, Carrera do not have a big variety of cars and neither sells the chips, so the variety is in the 1/43 analog market. I do not have a Pit Stop on the D143 track like the D132 pit stop, so I do not have to worry about that probably electric issue. The D143 track only has lane changers and my D143 pit stop is made with a lane changer. I have adapted a CU and have Position Tower and driver displays options on my D143 track, as well as the start light. To count laps I use 5 fuel adapter chips, 4 for the 4-lanes and 1 in the pit stop.

          This schemes helps me a lot. My D143 track is 4 lanes, so I will need to use 2 switches.

          PS: you can see pictures of my D143 4 lane track in my gallery


          • #6
            Great to hear it makes sense to some

            Quite impressive what you have done converting the D143 track to D132 electronics, nice work!

            For the analog switch box you could use two 4PDT switches and just "duplicate" my setup, but there are also 8 pole dual throw (8PDT) switches available, they can get quite bulky and a bit difficult to find, but then you would only need one switch.

            Another solution could be to use one switch that trigger two 4 pole relays hidden inside the box, but if you are like me and get headache by watching electrical diagrams then two 4-pole switches might be a good solution.

            The trick for me was to test everything with a multimeter until I understood what was going on, and then "prefabricate" each switch and re-test before hooking it up to the next part.

            Here is the analog power intake and polarity switch "prefabricated" and ready to be tested.

            I mainly used black and yellow cables since that was what I had on hand in 0.75 square mm (about 18 gauge), but that was not a problem, just made sure I was consistent with polarity all the way.

            Below is the diagram for the directional switch (analog):

            Note! This diagram does not follow the US standard for controller cable colors. In this diagram positive (+) is read and ground (-) is black. The actual cable colors from a Parma/PM/SCP-1/etc.. controller would be inverted.

            I have a question though, I have a spare BB + transformer and my son has a Carrera GO "Cars" track that I am considering to hook the BB up to. But just to be sure, the D143 lane changers are compatible with the BB?



            • #7
              Originally posted by 356speedster View Post
              I have a question though, I have a spare BB + transformer and my son has a Carrera GO "Cars" track that I am considering to hook the BB up to. But just to be sure, the D143 lane changers are compatible with the BB?



              • #8
                Tore thank you for the detailed info.

                concerning the BB and D143 SABATA provided the answer. if you want to know a little more about D143, enjoy this thread. many of your questions will find an answer there. if not SABATA and myself will help you.




                • #9
                  Originally posted by Burtonbr View Post
                  ..Don't do what I did and fry your pit lane leaving it connected during analog use..
                  I've been thinking about this some, and while some write that their pitlane entry has been connected to a digital/analog track for years without damage others have "fried" their pit entry circuit.

                  Could this be due to polarity alone? Carrera Digital has opposite polarity (on the rails) than the Carrera analog powerbase, so if you just swap the BB/CU with a standard analog powerbase and leave the pitlane connected then you feed the pitlane circuit with reversed polarity, and I suspect that is what may kill the pitlane circuit.

                  If you wire the track to run the same polarity on the rails while in analog mode (as I did with my analog box), I can't see why a analog DC signal should hurt the lane change circuit, since the BB/CU also feeds the track with DC voltage. But the safe way to protect the pitlane entry circuit is to feed it power directly from the BB/CU before the digital/analog switch, that way it will be isolated from the track when in analog mode.

                  I've successfully swapped out my BB to a CU and the conversion of the CU to work with my analog box took less than 10 minutes. But another question arise, what about the other accessories when running in analog? I have a driver display that survived a couple hours of analog power (and still works), what is the experience others have with leaving accessories attached while running analog?

                  And has anyone tried to protect the digital equipment from receiving the wrong polarity by using diodes? Not sure if that is doable for the pitlane, but the DD / tower, etc..??

                  Last edited by 356speedster; 01-27-2012, 11:53 AM.