Block detection and powered frogs via turnout motors

[Lancs_fus]

 

Hello group,

I have a layout board with ten tortoise motors already installed. These torti are wired to feed the frogs of my live frog modified peco turnouts from the tortoise internal switches. This all worked just fine with a red and black track A and B connection to the DCC bus.

 

I am now fitting block detection via a Digitrax BDL168 block detector. Before I install the BDL168 I understand that I need to provide track power to the tortoise but not from the detection zone wires as it will trigger as occupied each time the tortoise is switched.

 

My detection common is rail B red per the BDL168 manual diagram. I plan to tap into that red rail B wire to power one half of the tortoise frog feed. This red wire rail B does not touch the BDL168 so should be all good. For the black or track A feed, do I need to take it from the zone common before it is connected to the BDL168 terminals?

 

I know this is a Digitrax centric question but assumed others had approached solutions to a similar issue of block detection and powered frogs via turnout motors before.

 

Paul Hamilton,

Perth, Western Australia

[roundhouse]

I have block detection using a BDL168. I use a separate power supply to power DS64 stationary decoders. This has the advantage of allowing turnouts ot be thrown if there is a track short.

 

The frogs do need to be powered from track feeds in the same block that the turnout is in.

[Lancs_fus]

I have the stationary decodes which are Digitrax DS64s powered by aux power and not by track power so there is no draw from the track bus. If I power the frogs via the tortoise internal SPDT switches local to the track detection feeds, won't the BDL168 see this as a current draw and thus that the detection block is occupied?

 

Would it not then be prudent to have a separate bus before the BDL168 detector that provides this switchable current to the frog?

[chaz]

I have the stationary decodes which are Digitrax DS64s powered by aux power and not by track power so there is no draw from the track bus. If I power the frogs via the tortoise internal SPDT switches local to the track detection feeds, won't the BDL168 see this as a current draw and thus that the detection block is occupied?

 

Would it not then be prudent to have a separate bus before the BDL168 detector that provides this switchable current to the frog?

 

No. there will be no current draw unless there is a vehicle standing on the frog. Think of the frog as a very small section - it will act exactly as the rest of the section that feeds it.

[Lancs_fus]

Ok I understand now thank you very much. I mistakenly mixed up powering the motor which in my case is via the DS64 versus frog feed powering via the detection section wire from the BDL168.

 

As my peco turnouts have been modified for live frog feed and also have their own feeders to the stock rails and are part of the detection section I simply need to share all the black wires from rail A of the turnout and corresponding section its a part of with the black wire to the tortoise internal SPDT and connect all of these to the detection wire from the BDL168 that will provide power to the correct rails and to the frog when switched via the tortoise - problem solved.

 

I have not experienced break before make issues with these tortoise motors previously when routing power to the frog feed so should be good now to wire in the BDL168.

 

Thanks once again. I think I over think things sometimes!

 

Paul Hamilton

Perth, Western Australia