Powered Diamond Frogs ?


PowrCab

Active Member
Hi,
Far as I can tell there are no commercial diamonds (crossings) with insulated powered frogs..But, can/do hand-layers build them with powered frogs ?
I realize diamonds are more complex than switches (TOs) to build and so accept that there are none in existence...
I was just wondering whether this has been or can be, done, where in DCC an AR could perform the polarity changes to the frogs as loco hits them...
Or, via a toggle switch in analog DC. It's something which seems to not have been talked about much, if at all. Or, has it and I've just never could sight of it ?..
Thanks
 
I was just posting something about hand-laid turnouts in another thread. I've done diamond crossings too. It's a similar technology, but instead of a single switched frog, there are four. But at least they all switch at the same time! Yes, you could do it with an auto-reverse circuit on DCC, or manually on a DC layout, or perhaps there's a trick that could be used. For instance, if there's a turnout nearby that always has a particular setting if traffic is using one route on the diamond, maybe that turnout could be linked to control the frogs. It would be a nuisance to have to set a control for the crossing depending on which route you're using.
 
With PCB ties scored in the right places, it would be very simple to power diamonds if they are hand built. Same thing as powering a frog for a turnout, but in the case of the diamond you could simply gap the corners/frogs, score the copper cladding clear below the gaps, and power them the same way as you'd power the rails leading up to them, route-by-route.

Seems to me a commercial, DCC-friendly diamond would be easy to wire. Just solder feeders to the web of the rails comprising the diamond orientated based on the route and on the polarity/phase of the rails on either side.
 
Sure you can have powered frogs on crossings. I use a Tam Valley Frog Juicer to power the frogs on the crossing I laid. I have handlaid 5 crossings but only one has powered frogs because the rest are "dummies", that is no train actually runs on the crossing route. I don't use PC board to lay switches or crossings, I just spike things down to the ties.

Well technically, the four dummies do have powered frogs but nothing changes, they are always powered the same. I could make them "live" bby adding feeders and a Frog Juicer.

In a crossing, of the four frogs, two of them will always be the same polarity so they don't have to isolated per se. The other two will have to change polarity depending on the route moving through the crossing. On a previous layout the track "crossing" a main was a spur, so the switch leading to the crossing controlled the frog polarity and on the live crossing I have now, I use a Tam Valley Frog Juicer. Any auto reverser type circuit can be used in DCC. In DC you have to use a switch or relay and it can be driven by a detection circuit in the approaches (track current or optical).
 
Until today I'd no idea it can be/is done...I've never before seen threads/posts about this subject..But maybe just luck of the draw...
In the end, though, it still is something which has to be created by us, that there are no commercial diamonds offering the special design.
Watch ! Now a commercial one will become available for $45 (AR not included) ! Someone's bound to do it;..Waltrs, Peco, Atlas.
Thanks for all the replies...
 
Not sure how you would power it...
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Okay, dad joke quality... I know. Post #4 is correct, looking at the crossing as a "diamond", two isolated frogs need to be at opposite corners of the diamond. Those have to be switched, it's exactly like a powered frog on a turnout would be switched, except there are two of them. They have to be switched to opposite rail polarities. So, the switching circuit consists of a DPDT arrangement, with the switching contacts going to the frogs, the ON/ON contacts ("outer" contacts) connected to the rail feed conductors.

I found a good diagram, you can ignore for this discussion the transfer track at the bottom: https://model-railroad-hobbyist.com/files/users/cnscale/track3.jpg
In that one, the points labeled 1 and 2, are the powered frogs, represented in red for one polarity and blue for the other. In the diagram, the plant is set for trains from B to D. The only thing that changes for a route from A to C, is a change in the polarity of both frogs.
 
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