Simple track section problem
#1
Hi all,
I need to know what I am doing wrong here, I thought this should be a simple process but I can't get it to work!
I am constructing a simple end-to-end 00 gauge layout (terminus to fiddle yard style) and want to have two sections (station area and fiddle yard) controlled by separate controllers. I have split the track using isolating joiners. I have a H&M duette controller with each controller wired to each section. When I run a loco from one section to the other it stalls on track where the join is. A shunting loco passes over it fine and is then controlled by the other controller. I was hoping that having each controller connected to each section like this would enable be to run trains end to end with control passing between the two. How is it that the shunter passes between the sections fine but main line locos don't???
Many thanks in advance for any help offered!
Ian
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#2
Ian, you may have to use an isolated section with a DPDT switch to avoid this. I'm not familar with these controlers, are they seperate power supply's or is it one power supply with seperate throttles for the different sections of track? Be sure the tracks are wired the same with the same terminals feeding the same rails, regardless of the type.
Charlie
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#3
Hi Charlie,
What is a DPDT switch and how do I use it? Does it switch automatically or would have have to make the switch just as the train crosses the section join?
The Hammant & Morgan Duette is a twin controller using one power source.
Both tracks are definitely wired correctly, hence the shunter managing to pass the join successfully and carry on running in the same direction.
Thanks for your reply
Ian
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#4
Ian I am assuming you are using dc current. try reversing the wires to one section just for the heck of it. It should be easy to change back, just change them around on one of the controllers.
A DPDT switch would be used on a short section of track between the two that is completely isolated from both sections but supplied with power just like you would wire a reversing loop.
You do have an insulated joint on both tracks don't you? The small locomotive is possibly able to free roll far enough that it isn't a problem. I have seen it occur that even though the polarity is the same using the reversing switch you need to be sure that the reversing switches on each section are in the same position as the train moves in the same direction. using the same power supply with two different controllers shouldn't be any problem at all. In effect what you are doing is moving between blocks. Something very simple is causing this problem.
Charlie
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#5
Ian: Does the Duette have the reversing switch part of the speed control or is there a separate slide switch for direction? The slide switch would be a DPDT.

Does your unit that stalls have pickup from all wheels or does it pick up from one rail on one truck/bogie and the other rail on the other truck? If it does that, the unit could be stuck between the sections because it's trying to pickup from controller A and return to controller B.
The shunter probably picks up on all wheels so crosses the gap. It might cause a problem if you had one controller set for the opposite direction.


The best solution for your problem might be (well, it's how I do it) to have a selector switch on each block to connect it to either controller. Then you just put both blocks on controller A and run through. The selector switches would probably be a DPDT (double pole double throw) switch with a centre-off position.
If you want to have both locos on the layout at the same time, you will need some place to isolate one of them -- a siding or a piece of track with an on/off switch controlling it.

I haven't played with a Duette for several decades. I think that it has separate transformers for each controller, so your next option is common rail.
David
Moderato ma non troppo
Perth & Exeter Railway Company
Esquesing & Chinguacousy Radial Railway
In model railroading, there are between six and two hundred ways of performing a given task.
Most modellers can get two of them to work.
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#6
Hi Ian,

DPDT stands for, Double Pole, Double Throw, in other words, a switch that has two positions, and has two contacts that can have two positions. Electrically, usually wired as per below, enabling to reverse polarity on the output (right) side. The two contacts are mechanically attached, so they switch at the same time.    

It is also worth investigating how your shunter differs in it's power pick up, from mainline loco's. It could be that the front axle only picks up one rail , and the rear the other, while the main line loco's have power pick up from both rails on all axles.
I think that in combination with the way your throttle is wired internally, the mainline loco's therefore cause a problem with the electronics when both sections are connected through the loco's internal wiring, as if you would put a wire bridge between lets say both positive outputs on your controller.
If you have another controller with a separate power supply, try to experiment, and use this second controller to power one section. Set both in the same direction, observing the wiring polarity, and roughly the same speed/voltage. Then see if the main line loco passes okay.
If that's the case, then it seems your controller would be the problem.

The solution then would be to use a section of track long enough to handle your largest loco between both power sections, which is isolated at both ends. This then is connected via a DPDT switch.
However the switch would need to be connected as follows:
The common of each contact to this rail, input one of each contact to go to the yard power supply, input two from the terminus section.

You can then drive your loco onto this piece of track let's say from the yard with the switch in that position. This section of track is then fed from the yard. Once the loco is on the track entirely, you flip the switch and it is then fed from the terminus section. This should enable you to have it run from one end to the other without short circuits.

Koos
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#7
Thanks to all who replied to my post.
My brother sorted it for me, he's a little more experienced with electronics than myself!
He followed the instructions for placing a DPDT switch into my circuit, I laid the track and he connected the switch and it is now working fine.
Once again, many thanks for you help guys!
Ian
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#8
BR60103 Wrote:Ian: Does the Duette have the reversing switch part of the speed control or is there a separate slide switch for direction? The slide switch would be a DPDT.

Does your unit that stalls have pickup from all wheels or does it pick up from one rail on one truck/bogie and the other rail on the other truck? If it does that, the unit could be stuck between the sections because it's trying to pickup from controller A and return to controller B.
The shunter probably picks up on all wheels so crosses the gap. It might cause a problem if you had one controller set for the opposite direction.


The best solution for your problem might be (well, it's how I do it) to have a selector switch on each block to connect it to either controller. Then you just put both blocks on controller A and run through. The selector switches would probably be a DPDT (double pole double throw) switch with a centre-off position.
If you want to have both locos on the layout at the same time, you will need some place to isolate one of them -- a siding or a piece of track with an on/off switch controlling it.

I haven't played with a Duette for several decades. I think that it has separate transformers for each controller, so your next option is common rail.


A single pole-double throw switch (SPDT) will do the job. This means that one of the two wires from both power packs is a "common" and goes directly from the packs to the track. Each of the two other wires from the power packs goes to one end of the switch. The wire from the center tab of the switch goes to the track. You need one switch per "block". This is essentially the set up described above, but with less wiring involved.
You'll need to have the rail that is connected to the switches isolated from each other (plastic rail joiner or a cut in the track). The other rail (common) does not need to be gapped.

This is the way I had my original layout set up. It had about 8-10 blocks. so I know this works.

Good luck..!! And don't be afraid to ask for more help if you need it.
Gus (LC&P).
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#9
I missed this post yesterday. Happy to see that things got straightened out - - - - aannnd . . . .

Welcome Welcome Welcome Ian, to Big Blue Cheers Cheers
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