Replace the spring with ne, the current might be too weak.

well, It is more that only when I am pulsing it gos at full speed. If I am not pulsing nothing happens. So when I do the pulshe, It gos (ONLY WHEN I AM PUSLING) full speed. Now, just when I couple some wagons, it pushes the wagons (whit the buffer too) off the tarck. I looked inside the train, and it looks like it is getting a 24 volt pulshe, but that 24 volt is also going to the motor. My friends says this is very logic, he says that only digital could go in other direction whitout going forward. I don't think so, thanks for the help by the way

Hi,

You can try to open the locomotive ( which loco is it ? ),
and see what's happening to the reversing unit when the pulse occurs.

Maybe a wire is blocking the mechanism, or something else..





Best Regards
Joël

So it doesn't move (slowly, steadily) if you turn the knob slightly to give it, say, 10V? That would be somewhat weird as the connection seems to work (if you pulse) ...

A picture or movie might help us help you.

Ik weet niet welk model je hebt gekocht.
Oudere locomotieven hadden een elektromechanisch relais dat werd geactiveerd door de inversiepuls.
Locomotieven sinds de jaren 1980 hebben voornamelijk elektronische relais die circuits gebruiken om dit te doen.
Heb je een nieuwe set gekocht of is dit een ouder model dat je hebt gekocht (gebruikte of oude voorraad)?

I don't know which model you bought
Older locomotives had an electro-mechanical relay that was activated by the reverse pulse
Locomotives since the 1980s mainly have electronics relays that replace the older reverse units.
Did you buy a new set or is it an older model (used or old stock)?

The old models often required a higher reverse pulse than the newer models.
If the transformer is outputting 23-24V to an older model, it could cause the exact problem that you describe, where the locomotive charges off like a raging bull.
My older blue metal transformers used to send a pulse as high as 26-28V.
On older models, if it was due to the relay not fully engaging, it was possible to replace the spring or adjust the tension to ensure that the relay fully engaged with the pulse.
On more recent models, it may not be a problem with the relay, but rather insufficient voltage to fully trip it.

Over the years, line voltages have changed. In North America, the voltages vary between 110 and 120.
In Europe, the voltages would vary between 220 and 230. Today, it is more regulated and stays at 220.
A transformer that would emit 26V reverse pulse in the 80s might only emit 24V today.

If you know which set or model you bought, it would help us to be able to identify the internal components and assess the best way to resolve your issue.

Hartelijke groeten

Mike C

Good boy.




Certainly not. With 0V the motor will have no reason to run. Does it move with the trafo knob in mid position?



Must have been a wrong setup or a defective trafo / controller.

Not if operated within specs, i.e. not mechanically overextended, nor exposed to (very high, at least red glow) temperatures. And not rusty. Won't get stiffer, either, by the way.

I'd assume (too little info from OP) that the setup was bought second hand, and not all parts are what they should be: trafo too weak (reverse pulse considerably below 24V), or pre-owner messed with the loco reverser, or what have you...

Let us wait for complementary details from owner as requested.

Do we know for a fact that the poster is referring to 3074/3075 or could have have a more recent version that does not have the classic reverse mechanism? There were models with Electronic Reverse Mechanism, Delta and Digital 6080 all by the mid-1990s
The fact that the loco races off at high speed could be spring/voltage related on the old ones, but could be voltage related on the ERM version.

Regards

Mike C

That only works for the particular late model reverse unit that was pictured. There are several other styles of reverse unit that are adjustable like that.

There are at least 4 train forums in the Dutch language (er zijn minstens 4 Nederlandstalige treinforums en een Vlaamse)
One of those has contact groups, and one of those is situated in Rotterdam, you can come along with your loco and ask help.
(Een van die forums heeft een stamtafel in Rotterdam (https://wiki.3rail.nl/index.php?title=Stichting_3rail_-_Stamtafel_Rotterdam), en je kunt erheen met je loc om een hulpvraag te stellen).

So, if people cannot help you because of a language gap, try in in your own neighbourhood, in your own language.

According to my knowlegde of analog Märklin h0, your question has been answered, and that should be enough.
If not, try some of these forums: https://forum.3rail.nl is a Dutch Märklin Users forum.

To me, this looks pretty normal for analog mechanical operation. You can try to weaken / loosen the spring a tiny bit to reduce the well known "Bocksprung" (leap frog). Or, install an electronic reverser if not a full blown decoder to eliminate it to its entirety.

I don't see any pictures from TS, so you know things I don't, for example loc 3074 and transformer number and type 37540.
If you have loc and transformer number, it's easier to retrieve information.

There is no coincidence between an analog transformer (220, 230 volt) and the pulse on an analog loc.
(OK, just have to adjust the spring tense a bit, perhaps, intuitively).

There is a rather complex technical explanation for it (about changed electric current fluctuation on the European net),
and there is simple practical information (I know people using these old blue transformers with analog locs, without problem).
But don't use that transformer on a digital loc, the decoder will be burned and never works again,
whatever the voltage the transformer was meant for.
Analog blue and some analog white transformers are incompatible with decoder usage.

So if there might be a problem, this loc must have an electronic reversing unit (FRU in German) from either Märklin, Uhlenbrock, Hag or what so ever. And that unit then should be restricted to exactly 25 volt. I don't know any model of those. Those restrictions came during the decoder introduction.

On the contrary, I have 2 HAG reversing units (built for Buco), and they have a pulse range from 18-48 volt, caused by the relay type used to switch direction. As soon a pulse is higher than 18 volt, the (bistable) relay switches once. Capacitors prevent a next switch, based on the same pulse.

Anyway, all analog Märklin locs in the past were leaving the factory in a box with a leaflet.
(Second hand bought trains seldom have the leaflet included.)
In that leaflet was written (in 4 languages) what to do with and buy for that specific loc (reverse spring tension, oiling principles, asb change, a.s.o.).

Of this loc number (3074) I scanned 2 pictures out of that leaflet (and put them in an Album), and attached them here
(just to see how it works):

Fig 1:


Text (in Dutch):

you´re welcome...