Hey,

I got one of Märklins K 84 decoders, in the manual there is a way to control the old metal turntable, art. no. 7186.

At Sean Fanelli's train page, I've found this scanned image with a way to control the 7186 turntable using the K 84 decoder.
http://www.polar.sunynas...lis/turntable_wiring.jpg

This way, doesn't seems to work for me, neither do the way described in the manual for the K 84 decoder. Do anyone else on this forum have the 7186 turntable together with a K 84 decoder?

When I put on the K 84 decoder, and when I'm pushing on buttons on the keyboard, I simply just hear a click each time, it does not matter which buttons I push on or if I take for the first or last. The only thing happening, is a click.

...do I have to modify the motor of the turntable, before I can use this way with the K 84 decoder?

It's me again

The autor described the rebuilding of the turntable very detailed!
http://www.polar.sunynas....edu/~fanellis/turntable

The are several modifications needed before you can use the k84 decoder!
And in fact it is an old 7186 turntable and not a new one!!!

Greetings

Roland

Hi Zosch,

There is described a way (likely the one on Sean Fanelli's site). In the manual there is with the 6084 K 84 decoder I have. There's also something like the description Philip gave in Danish. But for me it doesn't work. I simply just hear a "click" when pushing any buttons on my (Intellibox)-Keyboard.

It is something like the direction should be connected to like the output 1 of the decoder, and then the third cable, the 'brown' one, should be connected to output 2. Then I could choose with red or green, in output 1, the direction. Like red could be to go to right, and green to go to left. When then it is activated, I can activate the red one in output 2, then the turntable should move.

Like:

Red (1) = Turn right
Green (1) = Turn left
Red (2) = Activate power (start moving)
Green (2) = Deactivate power (stop moving)

So if my K 84 has group 1, number 1+2+3+4. I should push on number 1 (red), and then on number 2 (red), then the turntable should move right over, until I stop it by clicking number 2 (green).

Thats like what I understood out of the K 84 manual.

But simply, when I click any of the buttons that should do anything with the K 84 decoder, I simply just hear a click. When it's attached to the Turntable 7186. But with my crane no. 7051. It works fine, when using both a K 83 and K 84 to control the 7051. So probalby the problem is not that the K 84 is defective...

In the K 84 manual, there's not written anything about it is necessary to modify the motor of the 7186 to control it. There's just shown a way like the way on Sean Fanelli's train page. But it does not work for me. Maybe I did something wrong, I just don't see that I made any mistakes.

I also see that Sean Fanelli made a few modificitations to the 7186. But I find it strange if it should be described in the K 84 manual that it was possible, if it is necessary to modify it before it works... - am I the only one who find that strange?

Hello Arne.
First of all i think you should try running the turntabel analog, if it funktions then i stil think that the previus mention diagram works - eksept i can not see any return wiering from the turn tabel ( ground or brown if you like).

Philip

The wiring surely is correct, except it has taken for granted that the turntable is connected by rails to common ground. Do you have a brown cable from the Intellibox to the track, and the turntable connected to this?

The schema was also published by Rutger Friberg in "Digitaltåg" 1988.

Lars

I don't own the 7186 so not 100 % sure, but it seems correct.

I think the turntable has a ordinary loco motor with two field windings connected to blue and green, and a mono stable relay or something connected between violet and ground. The brushes get contact with ground if the relay is closed OR the bridge is between it's rest positions.

So you could easily test it with ordinary AC. If violet and green are connected to yellow (and ground as above) it should go one way, if blue and violet, the other. If violet is removed it should stop at next rest track position. AC will give more buzzing sound than DC. But please, don't blame me if I'm wrong; any confirmation appreciated.

/Lars

I think the next step should be to connect some lightbulbs or similar, at all outputs from decoder.

This will help you, and us, to solve the problem.

Just a thought: When powered from digital source, the AC voltage will be of a much higher frequency
than the usual 50 Hz from a transformer, which means that the resistance in the coil
will be much higher than usual, and maybe causing the coil not to throw/pull.

If you supply the contacts of K84 directly from a transformer instead of "digital power" it maybe helps???????

( Not that Fanelli has done it this way. )

Per.