Converting to DCC.

[CraigB]

I currently have two separate DC EZ Track ovals running two separate locos.  One of the ovals has a left and right turnout to make a small oval within a larger oval.  I recently purchased EZ Command plus and both left and right DCC ready turnouts to convert that to DCC.  Now that ive done that im thinking about connecting the current DC oval to the DCC oval using more DCC ready turnouts.  Ive read that on DC layouts you can short circuit the system with too many turnouts.  Is that aconcern with DCC layouts as well?  Is there a general rule of thumb about how many turnouts or crossovers you can have on a DCC layout?

[trainman203]

DO NOT connect DC powered track to DCC powered track.  You will terminally damage everything.  You need to choose one or the other on connected trackage.  I understand why people want to try to keep partial DC, to keep locomotives they've already invested in. But really, it's like graduating from elementary school to high school.  It's a different game and you don't keep stuff from the earlier grades. Leave the training wheels behind and get the big boy toys.

Whoever told you that too many track switches would short out things doesn't know what they're talking about.  There are gigantic layouts with hundreds upon hundreds of track switches that cause no short circuit problems by their numbers. It's a non-issue unrelated to mixing DC and DCC power in the same trackage.

[Len]

The only time switches short things out is when you use them to make a reversing loop without adding the necessary gaps and reversing circuit. Whether is a toggle switch on a DC layout, or autoreverse unit on a DCC layout.

Len

[CraigB]

Thanks guys.  I wasnt planning to mix the DC with the DCC.  I would remove the DC power supply and then connect tho old DC track to the DCC track by way of DCC ready turnouts or crossovers.  If i dont have to worry about shorts it should work fine then.  Thanks again.

[trainman203]

Good.  I like the idea of being to change power sources .  I don't have that but I have a few DC engines from back in the Jurassic that I'd like to run sometimes.  I'm sure that some electrical engineer here can tell you how to set up toggle switches to go back and forth.

[Fred Klein]

Craig and Trainman, all you need is a DPDT (Double Pole, Double Throw) toggle switch. For this application, stay away from the mini or micro switches since, depending on the size of your layout and number of engines running, you may be pulling a few amps through the switch and the standard size switches can handle a greater amp load.

A DPDT switch has six terminals. Connect the center two to your track, one to each rail. Connect one set of the side terminals to the output of your DC power supply. Connect the other side to the output of your DCC controller. Now, depending to which side you flip the switch, you will either supply DC or DCC to your track. However, it is important that both the DC and DCC controllers be set to 0 before you switch power to the track just to be sure that everything is turned off in order to avoid shorts. If you you want to be a little more sure, they make DPDT switches with a CO (Center Off) position. In this position, the switch conducts no power to either side and your track is completely dead.

                   DC  Track  DCC
                       |     |     |
                     __    __    __
           Contacts             
                     __    __    __

Hope this helps.

P.S. One thing that just came to mind is that I have no idea how the decoders in DCC-ready turnouts react to straight DC current. So, if you have any of those turnouts you may want to do some research on the subject before you fry the decoders.