One way turning triangle

[buzz]

Hi
triangles, Wye's I think you in the US call them.
are generally on the not interested list due to the complex wiring that goes
with then and they are space hungry.
however I need a small fold down one to turn locos around.
I seem to recall some one published a simple wiring method for a triangle,
using diodes.
The trade off was it could only be operated in one direction for me this is not a problem.
Does any one know what the cct for doing this is.
regards John

[OldTimer]

There are some things in this life that are much more scarey to think about than they are to do.  Wiring reversing sections falls into that category.   

The smallest useful standard gauge wye that I know of can be made from three Atlas #3 wye turnouts, 3 pieces of 18" R track and 3 pieces of 1/3 18"R track, plus enough track to make the tail of the wye and hold your longest engine.  Not counting the tail track, this wye takes up something like 23" by 26".

I suggest that you go to your LHS and find an introductory book on wiring.  Atlas publishes and excellent one, especially if you are interested in using the Atlas line of electrical components.

By the way, if you are using DCC, wiring the wye will be exceptionally easy.  Hope this helps.
Old Timer

[Doneldon]

buzzzzzzzzzzzzzzzzz -

You have several options for wiring a wye or triangle, depending on whether you model in DC or DCC.  Let me offer the DCC answer first, as it's the easiest.  Several manufacturers, including Bachmann, make a small circuit board which detects the short circuit a reverse polarity causes and fixes it so fast the circuit breakers in the rest of the digital system doesn't even know it happened.  I used one of these (a Bachmann from ebay for $30) for a turntable and the installation was a breeze.  For a wye, just connect two wires to the three legs of the wye and also to the circuit board input.  Then connect two wires from the circuit board output to the three parts of the wye within the turnouts.  Depanding on the brand, you can also have the circiut board throw the turnouts, either directly or via a relay.  In any event,these tracks would all need feeders anyway, so there's no extra wiring involved other than detouring the wiring to the interior trak sections through the circuit board.

With DC it's only a little more complicated, but that means a little more complicated than simple so it's still easy.  You can either use DTDP electrical switches to revers the polarity of the track used in the wye or install track detectors which will do this automatically through a relay.  They can also use a relay to switch the turnouts if you want.

So go for it.  Wyes really aren't a big deal to set up.
                                                                                             -- D

[buzz]

Hi
Thanks for the answers.
I am running analogue DC I should have stated that.
I have seen diagrams for triangles and am trying to avoid all those wires crossing a folding joint.
the wires crossing the folding joint will eventually brake and this is the trouble spot I am trying to avoid.
Which is a big ask since I have no choice the triangle must drop down out
of the way when trains are not running
regards John
 

[NarrowMinded]

May I suggest you place a teminal strip on each side of your hinge and a flat ribbon cable like you would find in computers to bridge them. This should help create a clean And functional solution to your wiring problem at the hinge area, so you can feel free to use what ever wiring design you like best.

NM

[Doneldon]

John -

There's a simple way to get wires across a joint safely: Just bundle the wires, run them to the joint, turn them so they run parallel to the joint for several inches (maybe 15 cm or longer), and then turn them again so they feed onto the new surface.  NM's idea is good but it means terminal strips and tiny wires in the ribbon cable.  You'd have to keep that ribbon section very short.  A third possibility is to use plug in connectors so the wires don't take the stress but that can get expensive if you have lots of wires.  I've never discovered a down side to running the wires along the joint for a ways.

A last, maybe goofy alternative is to hinge the folding panel so it goes up rather than down.  You'd still have 90^o of rotation but it would put less stress on the wires because that rotation would be from 180^o to 270^o rather than 180^o to 90^o.
                                                                      -- D

[jward]

i see two fallacies in the original post.

it is a myth that wyes eat up alot of space. as old timer said, an 18" radius  wye using 3 atlas wye switches takes up next to no room. most of the room needed is used by the tail track. certainly, a wye takes up less room than a turntable with radial tracks. i know, i have one of each on a layout of about 30 sq ft total (a 4x8 sheet of plywood has 32 sq ft)......

the other myth is that the reversing section is complicated or expensive to wire and operate. on a wye with a dead end tail track, you have the perfect solution of using the contacts of a switch motor to make a simple autoreverser. wire the contacts to reverse the polarity of the tail track whenever the switch is thrown. using atlas as an example, they have an under the table switch machine with contacts for well under $20.....  best of all, wiring through the switch motor contacts works equally well with dc or dcc.....

[NarrowMinded]

John,
I like your idea better then mine, very simple and should eliminate wire fatigue and the resulting wire breaks.

[NarrowMinded]

A local live steam park came up with a hybrid wye/turn table it is basicaly a turn out but each turn out curves toward a turn table the table does not pivot in the center it pivots at the rear. The train stops between the turnout switches disconnects drives past the switch, backs onto to table then the table swings the loco around to the track leading to the other switch.

NM 

[Doneldon]

jward -

Your idea is a very good one if the original poster has switch machines with contacts.  He might be using EZ Track or sectional track and switches which lack them.  I'm not so sure that the metal fatigue issue changes; a feeder must go to the tail track no matter what.

                                                                      -- D

[jward]

if the wye is tucked into a corner, there is no need for a drop down table, thus no fatigue on the wires. and for those using the ez track switches, i assume these are twin coil type switch motors? if so, an atlas snap relay can be wired in parallel with the switch motor wires. the simple instructions to do this are packaged with the relay....

i am sure this wou;d require some modification of bachman's plug in wiring, but it shouldn't be any harder than splicing a new plug on a lamp cord.

[buzz]

Hi guys
I am using Peco set track & switches as it is close to the operator,
the plan is manual switch operation.
The whole layout is tucked in a corner and the location of the triangle
fouls a door way.
The house I live in is very small with small rooms so no matter what I do something will end up fouling a door.
regards John