Analogue, have I gone a bit too far?

I have a circuit with the catenary powered by a transformer and the track powered by 6699.

The idea is that the lights in the carriages can be controlled while the train is on the move. I have also incorporated some contact tracks (5146 etc) so that the carriage lights come on and go off when activated using a remote switch.

So far, so good.

Now I thought I'd replace the 6699 with our old friend 6600. Then using the 6600 functions the lights could be delayed or made to come on gradually. I also would not need the remote switch

The 6600 functions I am using are the variable ones for controlled acceleration and pause.

A problem arises.

Using 6600 with its functions turned off it performs as you'd expect and controls the carriage lights when the dial is turned. However, when you select the 6600 functions the set up shorts.

Why? The catenary power is not connected to the track power in any way except negative/earth. What have I done?

Perhaps it is time to question my sanity...

Jean,

Many thanks for your input. I have tested the 6600 and it has passed with flying colours.

A few years ago I had a conversation with Marcus Schild about 6600 and 6699. I see hasn't posted for ages.

My memory is not helping but I think he said that they both use pulse width modulation to control the loco. I wonder if PWM clashes with a normal controller in some way, maybe through a shared negative/earth?

Of course you have to remember that I do not know what I am talking about...

I own 3 of these lovely units. I originally planned to use them on my analogue layout, but eventually found that I could get further with PLC control, and at the same time avoid the problem with decoder-equipped locos entering the 6600 controlled tracks. (Analogue "5-star" equipped locos also do not work with the 6600 unit!)

BUT; I still have one of these units wired up to a station track, and actually went and performed a test based on your description above;
It works perfectly, and you are not going too far.

I hooked up 2 waggons with interior lighting; one with a LED strip, and the other with bulps.
I set the dial of the 6600 to (almost) max, and enabled the pause and reverse functions. The dials for acceleration, braking and pause I set to around half position, in order to see the effect well.
I then pushed the waggons slowly down the track, until it first trigged the BRAKE+PAUSE function of the 6600 unit, and then a little bit further down the track, until it triggered the REVERSE function of the unit.
Both events executed perfectly, with the lights dimming after the brake triggering, and flashing brightly (1 time) when triggering the reverse.
At the end of the pause, the lights slowly came back on again.
In no moment was the STOP triggered, or a short detected.

Sorry for this long-winded description, when a video cdould have shown it perfectly, but it was a rather uncomfortable position climbing onto the layout in order to try these "de-commisioned" cabled functions out.

So if your system fails, you should simplify the setup and double-check your wiring. (Maybe you got brown and yellow reversed on the 6600 unit¿?)
Also, be sure to have common ground between the normal trafo and the 6600.

Good luck!

The original design of the Wunderrad is to run for approx 3-4 minutes, then via a thermal relay, track power is cut for about 20 seconds.

The purpose of this is to confirm to observers that is it in fact the little 3000 Loco driving the entire display. And it's very effective.

I did some experiments with the 6600 a few months back and there are absolutely no issues with replicating this timing and I personally like the more smooth start and stop, the wheel doesn't tend to oscillate so much when stopping.

The *only* issue is how to trigger it. Hence looking at a 'counter'.

There is only one axle in the display that is standard and that I could tap off relatively easily. But I've experimented with M-M and Meccano gears (largely identical), and even M-plus system gears because they have a totally different range of ratio options and are designed to be fully compatible with M-M but I didn't get far.

One thing I quickly found was that if I used a worm-gear arrangement for example, the minute the number of revolutions (approx 10) was achieved, when the 6600 was triggered it would stop relatively quickly, but the trigger would remain active, preventing the 6600 from starting the acceleration again.

I'm sure there will be a solution, I even constructed a replica of the drive area so I could experiment on the workbench rather than the wheel itself but I had an exhibition looming so decided to employ a modern delay timer which works perfectly, 100% - except, it's not Märklin of course.

On the other hand, neither was the original bi-metal cutout, but it was installed by the factory when the apprentices built the model so it's still authentic, just unobtanium and definitely not worth trying to repair.

At the exhibition (as a guest of a joint Meccano & LEGO display) the reliability of it really grew on me, I also installed a PIR sensor so that it would only run when someone was actually in front of it. I toyed with the idea of an interactive switch that you maybe had to press or whatever to start it but that was just something else to potentially go wrong.

Here's a short video of the electronic timer in operation. That was a prototype, the final reuslt is slightly tidier but same idea.