Circuit diagrams of the "Glockenanker"-decoders "with regulation"
After having bought the Württ.C (3711), it occured to me that it didn't
behave the way I was used to from other 37-locos (i.e. the locos with regulated
decoder) when loaded. I analyzed the decoder circuit, and concluded that
it didn't show any regulation at all, which is the case with the regulated
"Glockenanker"-decoders from other manufacturers. The 3711 runs smoother
and "rounder" than the Delta version 3411 only because of the stabilized
voltage to the PWM. However, this doesn't help when the load changes. Moreover,
the old 701.13 chip was still built into the decoder. Therefore, no recognition
of the new formats, no extra functions and no intermediate
The circuit diagram of the 3711 decoder is found here.
When the model of the BR55 came out, many people were anxious to see if
Märklin had made it better here and provided a regulated decoder for
the loco. The first reports were not very promising: the speed seemed to
be rather load dependent. Thomas
Krüger finally made a prominent analysis of the decoder circuit.
If you compare this circuit with the 3711, you can conclude that the two
decoders hardly differs at all electrically. Therefore: No regulation,
only voltage stabilization for the PWM.
On top of this comes, as a further negative surprise, the fact that
Märklin still have built the old chip into the decoder. In other words:
a brand new loco, optically high class and expensively designed, was equipped
with an obsolete decoder chip, so that the new format isn't recognized,
nor are the four extra functions or the intermediate
speed steps available.
The circuit diagram of this 205965 decoder is found here.
My thanks to Thomas Krüger
who kindly allows the disclosure of the download..
Also this one is still equipped with the old decoder without regulation.
Only the special version of the BR17 seems to have the new regulated decoder for the
This translation was made by Per Zander from Sweden. Many thanks to him for this grateful work. Some mistakes you probably find are my work as result of trying to correct some misunderstandings.