65114Re: Marklin transformer polarity
- Jul 25, 2010Hello Willy,
Well, I wasn't clear at all about what I was asking in my original message. Sorry. I use the Atlas Wiring Book as my "bible" and I know that my track power is DC and Marklin HO is AC. However when reading chapter 4 where the section on blocks and multiple power packs is discussed, I wondered if there would be any effect if the transformers were not polarized. I see now from the replies to my original question that I do not have to be concerned about this.
Thanks again. And I will keep asking.
--- In email@example.com, "Willy Fritz" <willy.fritz@...> wrote:
> Dear luckykid,
> you NEVER can use anything written for Marklin H0 ! Because Marklin H0 is
> In your first post you remarked that you use Marklin Z - which is DC driven.
> As in soem other reply was already mentioned, you have to use some kind of
> block-wiring to attach more than one (original Marklin) power pack to your
> These facts are neatly printed on the power packs themselves using
> international symbols for DC (as opposed to AC) for the track contacts of
> the pack. You should know there are two different contacts for AC - they are
> ONLY used for switch magnets or layout lighting! Don't use them as track
> With kind reagrds,
> PS: Keep on asking - I hope, your next questions aren't about "How can I
> extingguish a fire in my train room?" :-)
> From: "luckykid43" <luckykid43@...>
> Sent: Saturday, July 24, 2010 5:56 PM
> To: <firstname.lastname@example.org>
> Subject: [Z_Scale] Re: Marklin transformer polarity
> > The replies to my question have helped me to find a good resource on
> > Marklin transformer polarity, although it's located in an HO document.
> > Eckert Engineering's booklet on the Electrical Aspects of a Marklin HO
> > layout has a section (8.0) on Multiple Transformers on Layouts. There is a
> > nice, illustrated discussion of polarity and includes a simple polarity
> > test procedure. The 15 page booklet can be found at:
> > http://www.lctm.info/FileView/_files/Folletos/Marklinwiringbooklet.pdf
> > Thanks for your help, luckykid
> > --- In email@example.com, "zeeglen" <glen@> wrote:
> >> --- In firstname.lastname@example.org, "luckykid43" <luckykid43@> wrote:
> >> > Actually, I was not clear in my purpose with this question. I thought
> >> > there might be a problem if I was using more than one Marklin
> >> > transformer/controller in my layout and the polarity of the
> >> > transformers themselves ended up different.
> >> > I hope that helps.
> >> This is a valid concern. I do not know if Marklin power packs are prone
> >> to AC phasing differences, but is known to be critical with some MRC
> >> power packs. There are two issues here, DC polarity (locomotive
> >> direction) and AC phasing if these power packs output half wave
> >> rectified.
> >> DC polarity is easily understood. Both power packs should be the same
> >> make/model and both set to the same direction as the loco crosses an
> >> insulated boundary between two blocks powered by the two individual power
> >> packs. Speed should be set to approximately the same on both power
> >> packs. If the power packs are inadvertently set to opposite DC polarity
> >> the loco will stall as it's wheels bridge across the rail gaps and the
> >> power packs drive each other into overload shutdown through the
> >> locomotive wheels, if properly designed no permanent damage except
> >> possibly to the loccomotive. The same can happen with a single power
> >> back when block boundaries are set to opposite directions, but less
> >> damaging current flows.
> >> Generally it is not a very good idea to have a locomotive cross a block
> >> boundary between power packs unless both power packs are the same make
> >> and model and set to the same speed, and definitely to the same DC
> >> polarity (direction). Differences in output waveforms (DC, halfwave
> >> sine, fullwave sine, pulse-on-DC) can make different models from the same
> >> manufacturer incompatible with each other when run in parallel (due to
> >> the wheels bridging the rail gaps) even for a short time.
> >> Even then the pulse phasing between the same models will not necessarily
> >> match, if so the AC power cord of one must be reversed. Involves
> >> rewiring if the AC plugs are polarized (one wide blade) and cannot be
> >> reversed in the wall outlet.
> >> If the power pack outputs half-wave-rectified sine and AC input is 60 Hz,
> >> output voltage pulses are present for 8 milliseconds followed by a gap
> >> (no voltage) for another 8 milliseconds, then the cycle repeats. In
> >> other words 60 pulses and 60 interleaved gaps per second.
> >> If using more than one power pack for separate blocks, the phasing must
> >> be the same so that as a locomotive straddles insulated blocks and
> >> momentarily receives and bridges power from both packs the half wave
> >> relative to AC line polarity must be synchronized among all power packs.
> >> Otherwise the loco will speed up while straddling blocks as it briefly
> >> receives full wave created from two opposite-phased half wave sources,
> >> even when the DC polarity (loco direction) is matched. In other words,
> >> the two power packs can alternately fill in the gap between each other's
> >> pulses instead of both producing the 8 millisecond pulse at the same
> >> time.
> > ------------------------------------
> > Z-scale: minimum siZe, MAXIMUM enjoyment!
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