Power Changes - Upgrading to Digitrax PS 2012

After years of denial and confusion - and a perplexing set of priorities - I decided to retire my trusty old Marklin/Trix power transformer that came with my first starter set (believe it or not, still perfectly fine at powering my entire layout!) and upgraded to the Digitrax PS 2012.

This was actually not a simple decision. For one, this power transformer costs around $150.00, so its a decent investment when an existing power supply seems to be working 'just fine'.  Or is it?  My original Marklin power transformer does work fine and has never had any problem powering 4 simultaneously running trains with lit passenger cars on sidings, etc... But, its average power outage is around 17 volts.

So I've been doing some reading... and I particularly recommend Ken Shores Sumida Crossing blog and this post in particular  on the 'standards' of DCC power supply.  Now, I've been fully aware for a long time that N Scale locomotives are basically built with the 12V DC power requirement in mind.  I'm also aware that I've been nearly 50% higher than that for some time!  "But" I would tell myself "this is the power unit that Marklin/Minitrix supplied with an N Scale train set, so it must be okay, right?"  Well, I suppose, but still, it just seemed wrong.

Of course, in addition to this confusion, my Roco Multizentrale set up says it needs a power supply that will provide between 16-18 volts AC or 18-24 DC.  Wow, again, more than should be needed or safe for N Scale in that standard! What's going on?

I really don't know, but I should be the first one to know that when you're dealing with electricity and electronics, its better to be safe than sorry.  So I decided that for the price of a locomotive, why not buy some insurance that I wasn't cooking my precious little locomotives as they raced around Quinntopia?

Installation was pretty easy.  Although - and this was weird, the switch on the back was set for 230v (not 115 that I need here in the US of A), so I had to flip that over to 115v.    It was easy to change, but I was confused on why it appeared to be set for a voltage that normally would not be the default setting for Digitrax products - and I even wondered if perhaps I was confused on what the labels on the switch actually meant.  Anyway, I went with my gut and flipped the switch so that 115 was showing and 230 was not, which turned out to be the right setting for me).

The one glitch when using this power supply (or most others) with the Roco Multizentrale is that the Roco unit requires one of those prong-like adapters rather than a screw terminal connection.
So I convinced myself that I could always undo whatever I did at this point, I snipped off one of those plugs from another older transformer and used a European terminal connector to bring it all together.
And - with a bit of a prayer - I wired everything together, flipped the switches and...it worked! No cloud of smoke rising form my Multizentrale! Hooray! And I now get a much more tolerable 13 volts (or so) of power to my track!

So far...everything seems to be working just as it was before.  I'm curious to see what this reduced voltage will do to the 'max speed' of some of my locos, but with some limited running, I haven't seen any difference.  And despite their extremely generous requirements for the Multizentrale, my Roco Multimaus system doesn't seem to have any problems either!

1 comment:

  1. Pierre.bln5/3/12, 3:28 AM

    Hey Jerry, good to play it safe for the voltage. However, just to reassure you, there is little chance you would have burned anything.

    I run at 14V-15V (digital current, i.e. "sort of" AC power) on my tracks, which is what "Tams Elektronik" advises for its booster on N layouts.
    In fact, most decoders (at least the one from EU manufacturers) usually go as far as 18 or 21V, which is the advised power for HO digital (our mini decoders do come helpful for some small HO locs).

    As for the "analog" lighting of the cars, well I am no electronic expert; but I would assume a 12V DC bulb can withstand 16V "AC" digital current. And as for the more recent LED carriages, they are designed to "withstand" digital voltages anyway.

    All this to say: I noticed an improvement of my trains' behavior on 14V+. My Köf II for example seems slightly less sensitive to rail dirt now.

    As for the max speed of your trains; you shouldn't notice any difference: all decoders regulate the tension sent to the motor in absolute values, not relative to track power.
    An interesting question though is for modern decoders that send pulsated current to the motor (rather than plain old DC). Since they use "peak" tensions to boost the motors at low speeds, maybe lower tension on the track will diminish slow driving capabilities.
    The ESU decoders of the 4th generation for example (the only ones I buy now), have a hidden "intelligent learning" function: the decoder drives the locomotive in an erratic manner for 2 to 5 seconds, and determines automatically the motor behavior to adapt all the "super-dupper-expert" motor CVs that I wouldn't have touched otherwise: some of my locomotives can now drive almost twice as slowly as before, without jumps.