Electronics and DCC

Hi,

I've also got screw type connectors to use for most all of my power districts.  As you wrote, this will allow me to easily split them up if the need for "more power" arises.  I suspect my power district that will include the sub-main and all attached industrial sidings and the yard may be a prime candidate.  But, as there will typically only be one operator, maybe all will be fine as is afterall. 

Your (and my) point is that it is much easier to wire for expansion & changes during construction, rather than after the layout is up and running (been there, done that).

Mobilman44

jbinkley60:

I power all of my staging tracks.  With DCC I can't think of a reason not to.

OK, now this newbie is confused again with this DCC/electrical stuff.  I'm not even sure how to pose the question but I think it has to do with "sizing" the system.

With the size of my layout, eventually I would have a dozen or more engines sitting on the layout - seven staged trains and a few engines in the Marshfield yard.  However, I'm only planning to support two operators.  This means at any given time, I would have 2-5 engines (a triple and a double) running and the rest "unused".

To size my layout, I am looking at amps - correct?  If so, is it the engines in use or all the engines on the track?

More specifically - I purchased the MRC Advance 2 (I know some on this forum will cringe, but it seemed like the best fit for me - time will tell), still in the box but I believe it's rated at 3 amps.  Given this, do I need toggles to power off unused staging tracks, or do I need power booster(s), or am I good to go?

Again, I appreciate your patience, and your willingness to share your knowledge and experience.

Hi,

I am wiring in toggles for my staging tracks (1 for the 2 passenger trks, 1 for the 4 freight trks), and also the loco terminal trks (1 for the 2 diesel loco trks, 1 for the 2 steam loco trks).  My reasoning is that the locos do take up some power just sitting there (esp. if they have sound), and that power could be needed elsewhere.  With you having a 3 amp system, I suspect it makes even more sense for you to do so.  Also, I am toggling both wires going to the tracks.  Yes, toggling only one should be ok, but I am doing both.

ENJOY,

Mobilman44

OK, after a bunch more Internet reading on this last night, this is where I'm at.

Originally, I was calculating total amps required for my layout as 6 engines max times .25 amps per engine, giving 1.5 amp, then double that.  So a 3 amp system would be suitable.  Idle engines sitting on the track - neglible so they don't count.

But, they need for toggles is really a work-around for insufficient power - amps.

Not sure how to calculate, but I really need more than 3 amps - probably closer to 6 amps?

So, lose the 8 toggles and all that extra wiring for the staging, going back to one bus feeding all of staging.  Instead, add more power (grunt here)!  The "proper" DCC approach woudl be two power districts - one for staging, one for the upper level - and divide the upper layout into three sub-districts for circuit protection/troubleshooting.

Am I on the right track here, or still way out in left field?

Dmarket,

I too had the same concerns for "more power", originally wanting to go with a 5 amp system and 3 additional boosters.  The knowledgable folks on this and the Yahoo Digitrax forums convinced me that I was going way overboard, and that a 5 amp Super Chief with a second booster would be more than enough - especially split into 8 sub-districts via two Psx4 circuit breaker sets.

I am a lone wolf operator (almost always) and typically would run two 4 unit ABBA consists (all powered) and perhaps a switching unit with my free hand. 

Having read a lot about the subject (but with little practical experience), I would split your layout into a number of power districts and perhaps add a booster.  Or, you may want to replace the Zephyr with a SuperChief later on - but I would sure go with what you have first to assure it is necessary.  By the way, Digitrax systems have excellent resale value on Ebay.

Keep us informed, for your "problem" is probably shared by a number of folks.

Mobilman44

If I were in your shoes, I would be looking at the maximum working amp requirement at any one time, adding 15% for a safety margin (20% wouldn't hurt), and then adding to that any idling/accessory requirements....including reasonably foreseen ones in both cases.

Two operators are highly unlikely to operate more than one train each, and if we assume that to be as many as three sound-equipped MU'd engines, that would come to about 2 amps per operator.  You wouldn't likely have all those MU'd engines pulling 10 car trains, right, so the 2 amps per operator pulling longish trains with three sound-equipped locomotives is a reasonable expectation, including the safety buffer.  You now have 4 amps total.  Add any accessories that may have to cadge off that power supply, or worse, off the rails themselves.

I have the Super Empire Builder which requires a 5 amp supply, and I would say I am glad to have it, even as a lone operator.  If you and a friend are going to be quite active at the throttle, I would expect 3 amps to be skimpy for the total number of sound engines that two operators would want to manage concurrently.

-Crandell

selector:

If I were in your shoes, I would be looking at the maximum working amp requirement at any one time

Thanks Crandell, you hit the nail on the head.  This is what I'm struggling with.  For maximum amps, you add the requirements of each individual device, is that correct?

That would mean your estimate of 2 amps for three sound engines equates to .66 amps per engine.  Am I thinking right?

What about the unused engines sitting on the track?  Most of what I've read says this is negligible, but I've read of some who go through the effort of toggles to power off staging or roundhouse tracks.  How do you work idling/unused engines into the calculation for max amps requirement?

 Idle locos with decoders do draw some power, but it isn't much. Sound decoders might draw a measurable amount, non-sound decoders, I doubt you could measure the draw without some rather expensive equipment. I haven't seen where anyone publishes the numbers so that you could accurately calculate how much power you need to run those 10 steamers with sound sitting on your roundhouse tracks.

 There are a coupel of reasons for the toggles. One is to just quiet things down - although with most sound decoders you can just mute the sound on parked locos using a function key without adding a toggle switch to kill track power. Another is to prevent accidents. If you have multiple locos of the same class, so that they have numbers close together, and someone over ont he other side fumbles keying in the number, they may turn up their throttle, wonder why the loco right in front of them isn't moving, so they turn the throttle up a bit more. In the emantime, they've just run a different loco through the wall of the roundhouse, or put it in the turntable pit, or pulled a train across an open switch in the staging yard.

                           --Randy

I think I've got it - here's my plan.  (But please, let me know if I'm still off-base.)

Wire the layout for five districts - one for each town on the upper layout, and one for each side of staging.  Start with the heavy duty barrier strips, then add proper circuit breakers as need/funds permit.

The PA2 with 3 amps will be good to start with my limited stable of non-sound locos, but will be insufficient if/when the layout is fully stocked with sound locos (atleast a few years from now).

Most importantly, no toggles to individually deaden the eight staging tracks!  You guys saved me from going down that wrong path.

Thanks again for your guidance and your patience.

Thanks, Randy, for continuing to help here.  I am sorry to be a whole 20 some hours before replying again.

Yes, I think the 0.6-0.1 amp range is not unreasonable for planning purposes with sound-equipped engines pulling heavy loads.  The drive trains vary, as do the decoders and their speakers, etc.  I think Randy would say to plan for 0.75 amps/locomotive these days.

Toggles can be had fairly cheaply and only need five minutes to wire them into a circuit if you are a klutz like me.  As Randy said just two posts back, they have their uses.  However, if you are not the absent-minded type and can recall why the noise is deafening in your train room suddenly, using F8 to mute unused engines is a boon....even critical for most of us to enjoy running our layouts.  You will find out for yourself that more than three engines within 15 feet at normal volume will be a test.  Even then, I reduce my master volume setting on every single decoder by about 40-50% right out of the box.  I don't like my wife calling to me that the banana bread is ready to come out of the oven when I have a steamer's bell ringing in the yard...she upstairs and me in the train room in the basement.  They can get ridiculously loud and strident.

But, aside from more peace and enjoyment, you get to sort through the individual sounds for two or three different types of engines which is kind of nice.  And, from an ecological point of view, all those muted engines mean a greener approach to power usage.  Your power supply runs cooler, always a good thing, and you use less electricity that is only going to end up annoying anyway.  Finally, you have a solid reserve of unused power at your finger tips.