Gotcha didnt I?
I am building a wye.
Now in the olden days with Analog power, you had to flip a switch to reverse the wye when the engine got onto what I call the tail track.
Today the only thing I know of for reversing with DCC is a older reversing unit that requires the engine to travel at a scale 30 mph across 4 inches of track so that the polarity will change.
I dont think so.
I am very worried about wiring this thing.
Should I defeat the Kato Power Routing with insulated joiners at all three switches?
Any diagrams or experiences you all may have will be most welcome because in my home this week is now electrical week for the wye.
wye oh wye do I get myself into these durn things?
Being a wye, i'd wire exactly the same way as you do for an analog layout. You don't need as reverser. When you throw the switch to throw the points on the turnout, it should swap the polarity of the wye.
Reversers are mainly used when trains are moving such as round a reverse loop - you don't need them for a wye.
Regards
Tim
You can wire it either way -- through a toggle switch or through an auto-reverse module. The result will be the same.
Even with power routing, you will get your dreaded zzzapp! as soon as the first current transferring axle crosses the boundary in the wye where the polarity gets reversed. Your lead powered axle will provide the short when it bridges to changed polarity and where the trailing powered axles are still in the other section of polarity. That position, anywhere at or beyond the frog of the tail when taking the second route when the far turnout permitting access to the main trunk is lined, provides opposing polarity to the one power drawing unit, so the short happens.
You will need a DPDT, or something much more costly, but hands-free, like Tony's Train Exchange PSX-AR.
I have a Tony's Autoreverser in mind I think it is one of the PSR units. The whole wye is going to be a bit pricey already. I rather have a solid state unit auto reversing and perhaps providing breaker protection as well.
There will definately be a seperate power bus to that district so that if it should short it wont bring down the rest of the railroad or the equiptment.
Im actually worried to the point of choosing a sacrifical engine for 10 bucks to fry until the thing works right.
Safety Valve wrote: in the olden days with Analog power, you had to flip a switch to reverse the wye when the engine got onto what I call the tail track.
Gandy Dancer wrote: ...Why, It sounds like you understand the basics from the olden days? Electricity is still electricity. I think you are worried about nothing.
...Why, It sounds like you understand the basics from the olden days? Electricity is still electricity. I think you are worried about nothing.
True enough. In any event, your DCC system will have self-protecting capability to deal with shorts when they happen. Let the engineering do the work! Correct the fault like you do in DC, and the system will automatically restore power to the tracks. You're back running trains.
If you elect to install the PSX-AR, it is sufficiently straightforward that even I got it right, and it works invisibly and silently as needed. It monitors that section of track that needs it, and does what you expect it to do as you run the engine into that "block". The nice part of it is that you can do it with as little concern as if you were driving a real locomotive...wherever you need to go, as long as the route is lined and clear ahead.
This assumes that one leg of the wye is a stub, not a through track.
If your switch machine has DPDT contacts (RIX and tortoise do, Atlas doesn't) all you have to do is wire them to connect the appropriate rails of whichever approach leg the turnout points are set for to the completely isolated rails of the stub wye leg. No reverser, no separate DPDT switch, no problem.
If your switch machine is already powering the frog, you will need 3PDT contacts. My old KTM rocksmashers have them, but they aren't readily available. An alternative would power a 12vdc DPDT relay from an SPST equivalent contact on the switch machine, leaving the other SPST for frog power.
Chuck (modeling Central Japan in September, 1964)
Bear "It's all about having fun."
tomikawaTT wrote: This assumes that one leg of the wye is a stub, not a through track.
Even if all 3 legs are stub-tracks, or even if all 3 legs are through-tracks, or a combination of stub- and through-tracks, you must have some way to correct (reverse) the track polarity.
All wyes, turn-tables, and reversing loops need to be wired with some method to correct (reverse) the track polarity. In each case, trains passing through the wye, turn-table or reversing loop will (or have the potential to) end up on its original track facing the opposite way. If you're not able to correct (reverse) the track polarity -- either manually or automatically -- there will be a short-circuit which has the potential to cause damage to your locomotive, its decoder, and/or your DCC system.