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The Prototype Märklin-H0-Knowledge Layout-Building Modelstock |
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A: The very first
basic knowlege about conventionally controlled Märklin H0 model railways A3:
How many transformers do I need - and which? |
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Every
starter set until 1993 contained the weakest transformer of the Märklin
programme at that time with only 10 VA, which was not in the catalogue
and therefore could not be purchased separately. From
1994 onwards, there was only the 6647 (later versions 66470, 66471) with
30 VA. A customer-friendly, sensible decision, as we will see in a
moment. With
the 10 VA transformer you can operate the train
from the starter pack, but hardly more. Even a large locomotive can overload
the small one. So,
what to do with the small one, which one is more suitable? What
do the electrical elements of a Märklin model railway consume? These
are the first questions. The answers lead to new... How much electrical power (VA) must
be provided? Note: The following explanations are simplified and may cause
contradiction among experts, but should remain comprehensible to the layman. The
power output of transformers is given in VA, the product
of the voltage and current output.
Every
multimeter can measure voltage in volts, both DC and AC. But
not every multimeter can measure the amperage in amperes for alternating
current, instead only for direct current and only with quite small values. Therefore,
we do not measure at first and rely on information published by Märklin in
its catalogues from 1963 to 2016 and in books. |
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Small locomotive |
9 |
VA (e.g. BR89), |
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Remark:
Transformers for traincontrol from Märklin were available in
three power classes: 10 VA, 16 VA and 30/32 VA. (complete illustration at the beginning of the article
"White - blue - orange...") |
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With
the 16 VA transformer, one could run a large locomotive and three
illuminated D-train cars. |
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Only
a 30 VA or 32 VA transformer offers enough reserve for larger
locomotives and longer illuminated trains. |
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Example
calculation: a larger locomotive (15 VA) plus 8 illuminated wagons (8x 2
Watt or VA) are a total of 31 VA and thus just about manageable with a
30 VA or a 32 VA transformer. Nowadays, LED lighting has
significant advantages. Or
a double traction with 2 V160 = 2x 12 VA = 24 VA plus 8 illuminated
wagons = 40 VA - no longer possible. If
you need more, you have to use a transformer from another manufacturer, e.g.
TITAN with 60 VA. I present a few variants of the TITAN transformers
below. What
can you use the small transformers for?
Solenoid
driven items such as points, uncoupling tracks and signals are better
supplied with a separate light transformer. The
same applies to house and street lighting. Over
the years, light transformers from Märklin
were available in the power classes 40 VA, 50/52 VA and 60 VA. (complete presentation at the end of the article "White - blue - orange...") Light
transformers are available from practically all model railway manufacturers.
As a rule, they all supply 16 V alternating voltage. How do you install a lighting transformer
in the control unit? 1st The transformers must be
connected in phase to a common connector strip. How to achieve this: 2nd the brown earth
connections of the driving transformer(s) and the lighting transformer must
be connected. This means that all earth wires go to both transformers. 3rd lead all yellow
connection lines of the turnouts and signals exclusively to the yellow socket
of the light transformer. Ring
cables with a large cross-section for earth and light would be a good idea,
then the supply cables of the consumers are short, the wire jam remains (at
first) clear. Up
to here we have been talking about one
train. What happens if you want a second
train to run at the same time? If
one transformer can handle two trains, they can be kept at a distance by
signal control. The wiring is a bit demanding. See my article "Automatic controls for line signals"
or the Märklin signal book.
Every
locomotive, even from the same production batch, has different driving
characteristics. No two locomotives travel at the same speed. This means that
double traction or pre-tensioning (you know the difference?) is always an
additional load for the locomotives involved. One wants to go faster and
tugs, one can't go as fast and brakes, even if the difference may be small.
To reduce the risk of derailment, take the faster one forward.... So
twin locomotives as the two fixed-coupled V36s, are built for higher wear.
The double locomotive V188 as well. Running
two trains on the same track without signal control will sooner or later lead
to a collision. Running
two trains on their own tracks with the same transformer makes no sense. It
might make sense to watch them do the rounds. In
short, a second, third independent train requires a second, third transformer
or a second, third controller. I
will now explain that a controller does not necessarily have to be a
transformer: Alternative transformers Transformers
with 60 VA are available under the
brand name TITAN, at least on the second-hand
market. At least two series are designed for plugging in additional
controllers. TITAN 108 Universal with TITAN 109M controller units. Housing
108 made of sheet metal (left) or plastic (right), depending on the series.
The 109M controller units in my possession all have plastic housings.
The
transformer itself has no control knob, but "any number" of control
units can be plugged in via a 5-pole socket row on the side, also those for
direct current, hence "universal".
The
5 sockets supply a range of alternating voltages:
This
results in a wide range of applications. The
AC controller units contain another transformer that provides the required
voltages for the nearly stepless train control. One
could get the idea to use these regulators as mobile units, i.e. to connect
them to the base with a long 6-core cable (5x input, 1x output: red to
track). This is quite possible, the controller units are handy in size, but a
bit heavy because of the additional transformer.
TITAN 808M transformer with controller knob plus TITAN 809M
controller units. All
housings made of sheet metal with control knob and switch button.
8
sockets on the side.
The
written voltages against the 0-socket. Further
intermediate voltages: 2 V between 6+8, 8+10,
10+12, 12+14,
14+16. This
offers a wide range of possible applications. The
plug-in controller units are light and almost empty inside except for a cable
tangle. Therefore they are even better suited as a mobile hand controller,
but on a 9-core cable. I have been using them for a long time. How good is the controllability with
the different transformers? Note:
Control
ranges measured at 230 V mains at my transformers: Märklin 6647 (66470, 66471) 32 VA Märklin 6631 30 VA Märklin 6173 30 VA Märklin 6413 10 VA Märklin 6511 16 VA Märklin 37540 10 VA TITAN 109M TITAN 809 M The
transformers with 4 - 5 V initial voltage are well suited for shunting
and gentle starting. The
transformers with a high switching voltage are still suitable for track
sections without the need for switching. Therefore
my recommendation is The division of the layout in
current sections There
are three basic types of circuit for the traction voltage:
The
section switching An
oval with one transformer, a switch, sidings behind it. If you want to park a
locomotive in a siding, you have to separate the centre conductor from the
oval, isolate it and give the siding its own feeding. If you lead this supply
line via a switch, you can switch off the siding section - this is the
principle of the “section switching”. This can be used for a bigger layout
too, but only one train will drive as its track ist aktive. All others wait. The
transition circuit An
oval with a transformer, a switch, behind it a shunting area with sidings and
a pull-out track, i.e. a separate play area. In order to be able to drive on
the oval, but at the same time to be able to shunt in the shunting area, a
second transformer is added to this and the centre conductor is isolated at
the turnout to the oval. Or: A
double oval, two parallel tracks, two independent routes, thus two
transformers. If there is a turnout connection between the tracks, the centre
conductor between the turnouts must be separated, isolated. In
both examples, the same thing happens when you cross the separation point:
When passing from one transformer circuit to the other, the speed of the
train changes, because it is impossible to set the two transformers
identically. With
the transition circuit, the locomotive's slider connects the two circuits. At
this moment, in the worst case, a life-threatening voltage can occur at
certain points. For this reason, care is always called for in the wiring. And
yet practically all publications of track plans are designed with section
switchings and transition circuits.
3
transformers are useful for this system: 1st: inner circuit 2nd: outer circuit 3rd: shunting area whereby
the aforementioned short circuit occurs at the transition from area to area. The
three sidings are connected to transformer 3 via three switches. You
can run two trains on this layout (with block switching even more), shunt at
the same time and park three locomotives. In
combination with block switching and distant signals, there is a concept that
increases the number of controllers: In
the prototype, the locomotive driver already reduces the speed when he
recognises at the distant signal that the main signal will be red. In
the model, this would mean reducing the driving voltage. This
is conceivable in one step with an additional controller, which is set in
such a way that the train approaches the signal slowly, and which is switched
to the track between distant and main signal, when the main signal is red. If
the signal turns green again in the meantime, the locomotive gets the normal
voltage again. Here we have a place with the transition circuit: at the
distant signal at the transition to the slow speed zone. Another
concept is to divide the track into several sections between the distant
signal and the main signal and to reduce the voltage from section to section.
This results in an even more prototypical view, but also requires several
transition circuit points. Wouldn't
it be nice to be able to run the train from the outer circle to the siding
without changing the transformer? This
is The
assignment switching Either
via change-over switches or with relays depending on the turnout position,
the used transformer is switched to exactly the track the train is currently
travelling on and to that it is about to travel on. The supply follows the
train from section to section. After leaving a section the supply is removed
from the left section and the section can be switched to another supply. In
my article "Siding tracks - parking
spaces for locomotives and wagons" I show and
explain an example of a assignment switching. With
the assignment switching it is possible to assign each moving train its own
controller. On a large layout with many trains "active" at the same
time, this means: as many controllers as trains and the number of switches is
maximum the number of controllers multiplied with the number of supply
sections... When
planning the feeding sections, it is also important to consider that at crossings all four feeders may be connected to each other
(see “Criss-cross
– The Märklin M track crossind and double slip turnouts”). This
means that if two circuits cross, this crossing must be a separate circuit,
each connected to the line being travelled. Because the crossing has to be
secured with signals anyway, this is only a small additional effort. |
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The Prototype Märklin-H0-Knowledge Layout-Building Modelstock |
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state: 29.12.2023 14:04 |
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Contact:
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