Electronics and DCC

Hi!

I'm using a good number of Atlas HO code 100 #8 turnouts on my layout (under construction).  In the testing process, I've found that some of my steamers will just not bridge the large unpowered frogs at slow speeds.  The Atlas package suggests hooking up their Atlas Snap Relay (item # 200) which will "easily" take care of the problem - allowing the frog to be powered appropriately depending on which way the turnout is running.

Could you explain:  How does the relay work?  How is it wired to the turnout/controller? Does its operation require hitting two "switches" when changing the direction of the turnout, or just the usual "switch"?

I thank you all for your help.  For something like this I would normally hit the LHS for the info, but I just can't get there for a couple of days.

Thank you!

Mobilman44 

 I assume you are using the regular Atlas switch motors? The Snap-Relay coils connect in parallel to the switch motor, so you only press the button once and it moves both the turnout and relay contacts. Are you using a capacitor discharge power supply? That will help greatly. As will ditchign the Atlas control boxes - the buttons like to stick and fry the coils.

 If you are usign Tortoises instead, there are already contacts available to power the frog without buying the Snap-Realy. The Snap-Relay won't work with a Tortoise (in an easy and simple manner anyway). It's nearly impossible to solder to the frog on the Atlas turnouts, so you need some other way of actually connecting the power - the Snap-Relay comes with the required hardware, and I know from someone else who built a large layout that Atlas will sell you just the hardware bits without the relay - this is how he powered all his frogs from Tortoise contacts. You cna also use a small brass nut and bolt and solder to that, or the same nut and bolt idea but solder the wire to a ring terminal and then bolt it to the hole in the frog.

                                        --Randy

Thanks Randy, you always seem to come thru !!!

Having been in the hobby since the '50s, I confess I never needed (or so I thought) to use the snap relay, but now it looks like it will be necessary.   Anyway, after I did the original post I recalled having an Atlas wiring book and I found it.  And, it has a chapter called "Using the Snap-Relay", which tells me everything I ever wanted to know about them.

I guess the only remaining question is whether I will need one or two relays for the four sets of # 8 crossovers on the layout.  Maybe someone "out there" can answer that for me!

Thanks again,

Mobilman44

Assuming the crossovers aren't the boundaries of different power districts, you should be able to set the frog polarities of both turnouts in a crossover with one relay. Since you diteched relays for a solid state option for your power districts, check out the Hex Frog Juicer from Tam Valley - a pair of wires to your track bus and one wire to each frog, and it sets the frog polarity automatically, like a DCC autoreverser.

                                   --Randy

Good Morning!

  I located the Tam Valley website and checked out the "frog juicer".  I then went to a couple of internet stores (including Walthers) and could not find it for sale.  It sounds great, but at $70 each, I would need two of them.  And, as I picked up 5 of the Snap Relays yesterday evening, it looks like I will stick with them.  This was my first knowledge of Tam Valley or the Frog Juicer, and I wish I had known about them (and my need for them) earlier on.

Anyway, my layout will have 4 double crossovers, with a break in power districts between each set.  It looks like I can use one Atlas turnout controller for each set, but will probably need two snap relays for each set.  Note that I am using the Atlas switch machines (either above or below the "table"). 

Assuming I go this route, the question is, "Will I need two snap relays for each crossover or can one be wired for both turnouts?"

Mobilman44 

 I believe you will need 2, one for each half of the crossover, since one side is fed from one power district and the other half from a different one. Since each relay id DPDT, you can feed each side of a given relay with opposite DCC phase ('polarity') so the two frogs that need opposite polarities can get it from a single relay. You can control the whole works with a single controller - but with 4 switch motors and 2 relays being tripped at the same time you definitely need that capacitor discharge supply and I'd also recommend something more robust than those plastic Atlas switch boxes.

                                           --Randy