Hi there.

It's been some time since i wrote the last message, but one allways come back to the forum :-)

My question...

I'm making a L shaped layout (4,50 x 1,25, and 3 m on the L side).

Is it better to put the digital acessories (like Viessmann relays, k83, s88, etc) near each other, in one location - the wirings are much longer with this solution...
... or, spreading the acessories near turnouts, signals, etc (below the baseboard)? (much less wiring).

I have this doubt in the shadow station, but this will be the same for other locations (main station, etc).

I think i like much better the second solution, but i can be missing something.

Thanks.

Although relatively small, the layout I am currently building has the decoders positioned throughout the layout: some to the left, some in the middle. I did this for two reasons:

- keep turnouts, uncoupler tracks, and signals on the same decoder as Lars mentioned
- allow for expansion

As I am using C-track, it is relatively easy to do on a small scale.

a bit of both. This is what I concluded and did and I have not regretted it.

I have one large power supply. (3 x 100W 16V AC) I positioned it far away from the computer because I used to use a CRT monitor and the power supply would interfere with the screen. I run heavy duty household wiring around under the layout to distribute that raw power and the digital signal from the IB and boosters.
http://layout.mixmox.com...plywithdistributionpanel
I tap into those wires wherever needed:
http://layout.mixmox.com...ringandpigtailconnectors


I placed my 'PC power 12V DC supply' next to the big AC power supply.
http://layout.mixmox.com/1/5_Volt_power (originally 5.15V but now 12.2V)

I placed all my ss8 modules close to the computer interface (Intellibox). This allows easy daisy chaining but means that I do have to run long cables from the track contact areas back to the s88 farm. I used shielded multi-strand (25?) cable for s88 feedback wires. By starting at the furthest point away, one can work back towards the s88 farm. When all the wires in the cable are used, rune the next cable from that point back to the s88 farm - thus minimizing the cable and effort needed. (I am cheap and lazy.)

For turnouts, I placed k83 modules close to the turnouts, as I could tap into a digital, ground and 16VAC easily at any place from the 'bus' wires.
http://layout.mixmox.com/1/20011230K83inplace

When it came to driving my signals however, I worked out that it would be best to groups the k83 modules and the signal modules together in one place. This was for a number of reasons:
1) economic. Each signal module needed 3 K83 modules and each k83 module has 4 pairs of outputs, so 4 signal modules can be driven with 3 k83 nodules. So it made sense to group the signal modules in multiples of 4.
2) I could mount and wire them all up on one big board and plug the whole thing in under the layout.
3) if k83 outputs fail, a single additional k83 module can (easily) be used to compensate for any 4 failures across all the signal k83s.
4) using multi-strand cables I could run multiple signals together in a single cable back to the array of modules. (Still cheap and lazy.)
http://layout.mixmox.com/1/signals-1

other tips:
a) use Velcro to attach the modules.
b) If you have lots of k83 modules, make yourself a k83 tester: http://layout.mixmox.com/1/k83-module-tester

Use Viessmann or other modules - better specs and cheaper than Märklin.

DPDT = Double Pole Double Throw, or what?
I agree that this should be standard, but I also want integrated solutions when possible. I like Viessmanns relais; there it's also easy to open the box and make some internal wiring as prefered; for example, I made some brake units with the diode and capacitator + some connections inside. But I would have prefered screw connections.

I can't even make up my mind for cable colouring, as I don't want to buy km's of new cable either. My common cables available at most places, however, are:
- Brown - 0
- Yellow - AC
- Red - digital from central (IB) to accessory decoders
- Orange - digital from boosters (Delta control) to track
- Green - DC - power to Viessmann k83, and usable with electronics.
I'm thinking of another colour for variable AC (lights).

/Lars

if you have multiple layers, put them under the lowest layer and runs the wires from the upper layes down to them like this:
http://layout.mixmox.com...Multilevelwiringsolution

I just noticed a small typo where I said k84 and meant k83 so that may have contributed to the confusion... sorry.
I used the Viessmann Signal modules. Each module can drive two signals or a one very complex one(such as a main with distance signal). These modules are switched using momentary impulses (k83 type) rather than latched on/off inputs (a la K84).
Each module needed 6 possible inputs (aspects 0 and 1 for one signal and 4 aspects for a second signal) - 6 inputs can be achieved from three pairs of k83 outputs, hence 3/4 of each K83 module is needed to drive each signal module. So each set of 3 k83 modules have one pair spare - thus being able to drive a 4th signal module - giving a ratio of 3 k83 modules to 4 signal modules.