Wiring problem - insulfrog points

[philiprporter]

I'm trying to restart an n-gauge project that I had to put on hold a couple of years back for health and work reasons - all was going well last week when I restarted and I finished laying track a couple of days ago. However, I am now stuck, as the electrics are not playing ball, despite me thinking that this would be an electrically simple layout given that I am using insulfrog points throughout aside from one electrofrog point on the scenic side. A track diagram is shown below and the important points are as follows:

 

1. The black and white triangles to the lower right represent track feeds - 1 controller is meant to control loops 1 and 2, the other is meant to control loop 3.

 

2. The red point in the scenic area is the only electrofrog point - both diverging exits from this point have insulated fishplates inserted into all 4 rails (represented by the vertical double lines in the diagram). All other points (black in the diagram) are insulfrog and there are no other breaks/insulated areas. There are no slips, crossings etc.

 

3. My idea was that I could run a train clockwise on loop 3 and then run it via the two facing points on the left hand side of the track diagram onto loop 2 such that I could run the train into sidings c and d assuming no train is active on loop 2 at that time (i.e. loop 2 is receiving no voltage). I could then reverse this train out from c or d and run via loop 2 in the direction of the arrow.

 

4. Similarly, my idea was to be able to run a train counterclockwise on loops 1 or 2 and then run via the facing pair of points on the right hand side of the track diagram onto loop 3 such that I could run into sidings e or f should I so wish (and again assuming there is no train running on loop 3 at this point in time). I could then reverse this train out from e or f and run via loop 3 in the direction of the arrow.

 

Having traced the feeds and knowing that I am using insulfrog points in the fiddle yard sidings I thought that this should all have been possible - but whenever I try to run a train from loop 3 to loop 2 or from loop 2 to loop 3 the loco stops almost dead (it does in fact continue to move, but very, very slowly) as soon as the points are switched (the facing pairs of points on the right or left hand sides) to allow the crossover to take place.

I confess that my electrical skills are limited (hence I havent permanently fixed the track in place), but I'm struggling to see why there should be a problem (presumably its a short of some kind?) given the use of insulfrog points and the fact that the track circuit appears to make sense to me on paper?? I'm totally baffled so can anyone help? I'm hoping that I'm just being dim and missing something obvious? Any advice would be sincerely appreciated - much trawling on the internet hasnt yielded much, aside from examples using a reverse loop which doesnt really apply to this situation as far as I can tell?

Best wishes, Phil.

[Il Grifone]

The only thing I can see offhand is the possibility of interaction betwween the two supplies. You could try disconnecting one and see if it makes any difference.

[Dagworth]

Does the controller that is NOT in use when driving across the crossover have an OFF position on its direction switch? If it is ON - forward or reverse - but with the knob turned to zero it will still be electrically conductive (assuming an electronic controller it will also be at risk of damage)

 

Andi

[naugytrax]

Yeah, what I was going to say. Mind you, I think you could have got away with this in the old days when controllers were just variable resistors and low speed was obtained with a high source impedance from the controller and "stop" really meant "open circuit". It's modern transistor controls which introduce this slightly counter-intuitive behaviour.

[Dave777]

I can understand the approach that's been taken, but for me a very simple cab control setup would make for a more secure electrical setup.

 

This is far from my area of expertise (if I had one anyway), but essentially you would split the layout into two seperate circuits:

 

Circuit 1:

Loops 1 + 2, with sidings A, B, C and D

 

Circuit 2:

Loop 3 with sidings E and F

 

The electrical feed for each circuit passes through a switch that can be switched to controller 1 or 2. Normally you would operate like this:

 

Circuit 1 switched to Controller 1

Circuit 2 switched to Controller 2

 

When you need to move a train from Circuit 1 to Circuit 2, you do this:

 

Circuit 1 switched to Controller 1

Circuit 2 switched to Controller 1

 

With the entire layout now running off Controller 1 you run the train across the crossover from one circuit to the other. Once across you then do this:

 

Circuit 1 switched to Controller 2

Circuit 2 switched to Controller 1

 

 

Only needs the addition of two switches into the feeds.

 

I would try some of the isolating techniques described above first though.

 

 

 

[Suzie]

Move your feed for circuits 1 and 2 to actually feed both circuits just to the left of the insulated joiners instead and ensure that your controllers are isolated (each have their own transformer or transformer secondary wiring - no "circuit controllers" allowed in this scenario).

 

All transfers between circuits 1/2 and 3 will be under the control of circuit 3's controller, and circuit 1/2's controller can still then be used for operating the remaining bits of circuit 1 and 2 at the same time. You could easily add an extra controller with the feeds repositioned this way should you want to run three trains.

 

You might like to move the insulated joiners on the live frog point left a bit to make it easier to transfer trains from circuit 1 and 2 to circuit 3 using the right hand crossover for improved operational flexibility, but there are swings and roundabouts with doing this, especially don't park a train across the insulated join!

 

Full cab control with common return wiring and live frog points throughout would be my recommended way to go if you want to stick with DC, but will be a tad more complicated to wire and you may be able to cope with the shortcomings of your simple wiring anyway so you might as well give my above suggestion a go.

 

 

 

[10000]

I would suspect its a conflict between the 2 controllers.

I have seen this aspect of engines crawling but not stopping completely and it was due to controller conflict.

 

I make the following observations

 

1) your controllers must support common rail/return or you will get a conflict.

 

2) better to have a double break in the track between the points that form a cross over between separately controlled loops

[philiprporter]

Thanks very much indeed to everyone for the very helpful comments and my apologies for the delay in replying - it does indeed appear to be a controller conflict problem - I'm using a Gaugemaster twin track 'D' controller and if I remove the wire from one of the outlets at the back (i.e. remove all electrical contact with the loop not being used) the problem is solved.

 

This controller does indeed have a centre off setting for each control as mentioned in Andi's post (sliding switch that controls direction for each controller) and this has the same effect , so would simply selecting this centre off position on the unused loop when switching between loops be the easiest way to remove the problem? Presumably I would need to switch at some point in any case if I were to insert insulated plates between the facing points so I may be avoiding the need for extra wiring by using the contrller switch? This of course assumes I remember to do it!

 

Any comments on this would be very welcome and am hoping that once this is solved I can get on with scenery and start a layout thread!

Best wishes, Phil.