Running dcc then dc

[TaffsTT]

I have a dcc feeder track section at rear and a dc feeder track closer in. Is there any reason why I cant run run one or the other?

E.g. i have two locos with sound and one dc. Can i run them seperately with no issues if only one or the other straight is connected at a time?

[P-Henny]

In an ideal world. Any DC section and DCC section should remain totally separate, both physically & electrically then there would be no issue.

The required separation has to be more than just using insulated rail joiners (IRJ), because any rolling stock that traverses the IRJ will electrically connect the DC & DCC controllers together and this has to be avoided.

Your query is slightly different in that you have a DC power connection and a DCC power connection connected to the SAME track. You will have to ensure that ONLY ONE controller DC or DCC is connected at a time. This means complete disconnection of the unused controller, not just turning it off.

But note this. The DC power connector is very likely to contain a suppression capacitor wired across the two rails. This capacitor will disrupt & corrupt DCC Commands and could cause operational issues. For example, commands being missed or misinterpreted. Therefore it would be wise to replace the DC power connector with a DCC one. This will not affect DC control.

Or better still, do away with the DC power connector altogether and only use the DCC one. This would have the benefit of forcing you to disconnect the DC Controller when using the DCC Controller and visa versa.

[TaffsTT]

Thankyou P-Henny. I thought I might be alright. If the points have clips can you see any issues as I now envisaging shorts as only just discovered I need clips.

[P-Henny]

See my later edit to my original reply that contains important additional [But note this.] information you may not have seen when posting your reply.

Since you say you have only one DC Locomotive, then the DCC point clips will make the whole layout live when connected to the DC Controller. Therefore that one loco will be able to transit across all parts of the layout without the need to set specific point routes for power transfer. With one loco, this is not an issue. Shorts would only occur if there are crossed wires or the layout incorporates a reverse loop. There is no reverse loop in your current posted layout design and with only a single DCC power connection (recommended) no risk of introducing crossed wires. Any shorts would affect BOTH DC & DCC operation.

Why not just convert that one DC Loco to DCC by fitting a decoder. Issue solved.

[Going Spare]

I hope you will not mind me making a suggestion regarding the track layout itself, which I think will help its operation.

The headshunt to the right of the grey base is very short and will probably be able to accommodate little more than a locomotive, making servicing the three sidings in the left foreground very difficult.

If you were to change the access point to those sidings from a lefthand to a righthand and connect it directly to the point coming off the main oval, the headshunt could be increased by at least the length of the redundant curved track section.

If you can find a way of lengthening the headshunt even more, you will be able to move more rolling stock between the sidings and the main running ovals at any one time.

[Rallymatt]

I am going to make a wild guess, you have two HM DCC equipped Pacifics and a non DCC shunter? If you only use the app for operating the DCC locos, the capacitor in the power track is not going to be an issue as the data is sent to the decoders Over The Air rather than via track power. However the idea a physical swap between control systems would be very wise to prevent unintended disasters!

The change I would be looking to do would be to make the 08 DCC with a regular DCC decoder and obtain a DCC controller, Hornby Select is inexpensive second hand.

Beware, if you use a traditional DCC controller to provide track power you MUST remove or have the DC locos completely isolated from the DCC fed part of the layout. It’s generally not advised to mix DCC and DC operation on the same layout.

GS makes a very good point on the short headshunt

[Fishmanoz]

If you are going to use a DCC controller not just the app, Paul’s earlier point about the capacitor in the DC power track remains as an issue.

Easy to fix though - just open up the box with the press buttons and springs where the controller feed connects and clip out the capacitor and reassemble.

Note the position of the springs and ensure you reassemble correctly. They will likely ping out when you take the top off the box.

Removing that capacitor will not affect DC operation and is essential for DCC.

[TaffsTT]

Thankyou very much and I dont mind at all any help or suggestions to help me and others.

I have a William Whitelaw without a dcc decoder so far out of three locos in TT120. For simplicity (as I do complex in OO) in TT I will just get a decoder for the A4 but did want Class 08s dcc too.

Thanks all for the replies and suggestions. Most welcome.

[ntpntpntp]

@FMR Definitely heed all the advice about keeping DCC and DC track power controllers totally separate and never be able to link the two through the rails or wiring: disconnect one system before plugging in the other.

With DCC trackwork don't be tempted to use any "run a DC loco on DCC" support the DCC system might offer (some do, some don't). That capability can destroy small modern motors and fell out of favour many years ago.

If you use HM700 bluetooth powered by the suggested DC power supply, any DC loco placed on the track will zoom off at full speed to its death on the floor!

Personally I'm not a DCC sound fan in small scales and also not a fan of touch screen control, but I did recently invest in an HM7000 Next18 sound decoder for my WW A4 just to try out the system with the app. I found the decoder £15 cheaper on Amazon than direct from Hornby :)

[david_watts1]

Might be an idea to lose one of the inputs and just swap power supplies with the one so DC and DCC can't accidentally mix.

[TaffsTT]

So after great advice abd suggestions I have removed the dc power straight and will leave all dcc for now and for ease.

Re-arranged the shunting yard and I think with another point to get a spur up in the left hand area will fill that gap area a bit. Thoughts you kind people?

[Going Spare]

That really depends upon what scenic features you are going to incorporate. One of the sidings could be doubled to feed a two-road engine shed while the others form a goods yard with coal staithes, goods shed, etc., which will need road access, as will any station you have, village, low-relief factory on the far side siding, etc.

[TaffsTT]

Thoughts?

[TaffsTT]

Bought a Next18 decoder for William Whitelaw but I now have issues of loco cutting out.