DCC Question

[Rod in PA]

I'm currently running a dual cab, direct current, 8' x 10' HO scale layout.  Each cab has a hardwired DC ammeter and voltmeter.  I'm thinking about converting one of the cabs to DCC.  My question is, can the DC ammeter and voltmeter be used with a DCC system (I'm 99% sure I am going with the MRC Prodigy Express)?  Any help or info would be greatly appreciated, thanks. 

[Jim Banner]

No.  Your ammeters and voltmeters are designed to measure dc.  With DCC, you are using a special form of ac.

There is, however, a combination ammeter and voltmeter designed specifically for measuring DCC current and voltage.  It is called an rrampmeter and is produced and sold by Tony's Train Exchange.  Click on the link below for more details:

http://www.tonystrains.com/technews/rrampmeter.htm

Jim

[Rod in PA]

Thanks Jim, that's what I needed to know.  That web link is very informative.  Thanks again.

[richg]

Our club converted to DCC and both meters are of no use.
I made a DCC amp meter and DCC voltmeter.
Many do not know how to do that so the Ramp meter is the best to use.
Many put the Ramp meter right where the wires connect to the controller box.
One thing to be aware of, if a poor track section, the Ramp meter will not be of limited use. You will see the current fluctuate or drop quite a lot depending on how much current the loco requires.  The loco will not run at all or not very well.
If a short, the current will max out until the controller shuts down. Voltage will gor to about zero.
As you gain experience, you will learn a lot about this.
Our club uses a cheap multimeter on AC with a 1156 auto light bulb as a simulator for a loco to check sections of the layout where there is a problem. We compare the reading at the controller box and the section with a problem. Some meters may not be accurate but we are concerned with relative readings in trouble shooting. As an example, 15 VAC at the controller and 8  volts AC at a track section tells us there is a continuity issue.
Many in our club are old school as we learned how to trouble shoot auto electrical with just a light bulb and a pair of clip leads. With DCC, the only difference is it is AC voltage but we still know high tech stuff.

Rich

[Doneldon]

Rod-

Be sure to use break-before-make switches for your cab selectors.
You don't want to connect DC and DCC for even an instant.
                                                                                        -- D

[Rod in PA]

I'm using on-off-on switches for my cab selectors, so I should be okay in that regard - right?  As for amp and volt meters, that will have to wait until I see how this DCC venture works out.  I'm going to order the MRC Prodigy Express sometime within the next few weeks; hopefully it installs and works as easily as the reviews say.  Thanks all for the info.

[railtwister]

Rod,

Using both DC and DCC on the same layout is a recipe for electrical disaster. Even if your block power is controlled with break-before-make switches, it's only a matter of time before someone makes a mistake, and a loco crosses over the gap between power districts, resulting in a short that could damage decoders or the whole system. If you must have both systems, set up a main power switch for the entire layout that selects either DC or DCC for the entire layout, and prevents having both on at the same time.

Bill in FL

[jward]

rod.

i wire my layouts with dc block control but use dcc. i find the block selectors help me to quickly isolate short circuits to a specific part of the layout. i can run the rest of the layout until i can fix the problem area.

if i may make a suggestion regarding the dcc system....

have you looked at the digitrax zephyr? it will allow you to use your two dc cabs as extra dcc throttles. most other systems do not allow you to do that, and dcc throttles are expensive, so you can save a couple hundred bucks right there. just sayin.....

overall, i think most people, once they try dcc and learn it, prefer dcc over dc. it takes a little effort to learn some of the things you can do, but it is well worth it.

[blf]

Rod: I'm wired for DC, but use the MRC Tech 6, which gives me the option to secelect which type of current I want to use. This way i don't have to put decoders in 100+ engines. The down size is it will only address 6 engines at a time, but who needs to run that many different locos at once. If you run a consist of say, 3 diesel units ,I just keep them on the same address which only uses 1 of the 6. Love it! Accesses all the sounds and changes CV's with the hand control.  Bill

[Rod in PA]

After an evening of researching a variety of DCC systems (nearly creating an overload), I've decided to stick with my original plan.  I still like the idea of having both DC and DCC available.  However, I never planned on trying to use both at the same time; I agree with Bill in FL, that could result in a costly disaster.  The DC cabs of my layout each have their own switchable power supply, one of which would be replaced with DCC (still leaning towards MRC Prodigy Express), and use only one or the other at a time.  I also like the idea of using block wiring for DCC, as this would provide a means of isolating trouble spots as suggested by Jeffery.  Thanks to all for your inputs and info, I'm sure I'll have more questions later when I convert the one cab to DCC.  Thanks again, Rod.