Frog Juicers compatible with RailPro?

[TwinStar]

Bill and Alan:

Not what I wanted to hear but I can understand. If a design, part numbers, or a kit was ever assembled I'd be all over it and just build my own. The problem is that I'm a very short bus electrical guy. I need lots of part numbers and colored instructions.

[G8B4Life]

Tim, there is no need for zero stretching (with a booster or with the new PDC converter) unless you are operating DC locos. RP modules rectify the track power so all AC frequencies and duty cycles produce the same result inside the LM.

Alan,

If you read my reply again you'll see that I was saying that the circuit design by Rob Paisley generates a zero stretched signal but one would want to change that to the normal DCC signal by changing the component values, but it could possibly work as is anyway.

Continuing on this discussion because it is interesting, Robs design is the closest thing I found to a usable circuit for driving a DCC booster without an actual command station, though there are a few questions that I'd like to ask him about it.

I did some looking at the relaxation oscillator design online and found a few designs that provide the necessary swing from + to - and back again ad infinitum but with all of them they don't provide the opposite phase required for correct output to the track for using directly (see the right hand side of Robs circuit). I don't know how one would make it work without even more circuitry on the oscillator part.

This is a link to some designs on some forum on creating a square wave AC signal, with the relaxation oscillator design given a few times (probably only of interest to Alan): https://www.edaboard.com/showthread.php?292062-Dual-polarity-square-wave-generator

Edit: Reading the NMRA standard for Power Stations (Boosters) you should be able to drive a booster with a unipolar signal from a relaxation oscillator fairly easily (a bipolar signal would be harder, a bipolar signal has to present to the booster differentially across the inputs of the booster). https://www.nmra.org/sites/default/files/standards/sandrp/pdf/S-9.1.2_2012_07.pdf

- Tim

[Alan]

Alan,
If you read my reply again you'll see that I was saying that the circuit design by Rob Paisley generates a zero stretched signal but one would want to change that to the normal DCC signal by changing the component values, but it could possibly work as is anyway.
- Tim

My apologies. Brain saw zero stretching and jumped to a conclusion.

I did some looking at the relaxation oscillator design online and found a few designs that provide the necessary swing from + to - and back again ad infinitum but with all of them they don't provide the opposite phase required for correct output to the track for using directly (see the right hand side of Robs circuit). I don't know how one would make it work without even more circuitry on the oscillator part.
- Tim

The circuit I showed is just a basic oscillator and was included since the message was introducing oscillator into the discussion for the first time. Yes, additional components would be needed in a final design. The inverse output (as you note), output driver transistors, and overload protection are a few obvious needed additions.

Regrading the inverse output, that could be accomplished any number of ways. You could simply add a second oscillator 180 degree out of phase to the first. Or you could add a logic NOT gate (inverter) tied to the oscillator output to get the inverse. Or you could do it in with the output transistors themselves - P channel and N channel outputs similar to audio amplifier output stages although this approach would require fine tuning to manage DC offset but it could be done. Point is the task of creating an AC square wave is not revolutionary. It is quite common in many electrical devices.

[EDIT]
Realized an easy way for everyone to visualize the DCC-simulation power supply - Consider the inverters sold for cars, campers, and boats so people can run 115V AC appliances from the vehicle's 12V DC electrical system. The DCC-simulation power supply would work the same except at different voltages of course and instead of outputting a sine wave it would output a square wave. Otherwise, same same.

[Alan]

Hmmm... inexpensive starting point:

https://www.ebay.com/itm/ICL8038-Function-Signal-Generator-Module-Sine-Square-Triangle-Wave-Output-Kits-S/401386381107?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160727114228%26meid%3D61d19766d757442cb4f60dd17abf03e3%26pid%3D100290%26rk%3D3%26rkt%3D4%26sd%3D201835571136%26itm%3D401386381107&_trksid=p2060778.c100290.m3507

[BruceRogers]

I've been using Ring's AR-1 as a frog juicer. Works perfectly even though it's a little pricy, the frog can be connected to either RT1 or RT2 output.
Tim Ring says the RT1 is the strong output from an electrical point of view.

[Tom]

Bruce,

Have you tried connecting RT1 & RT2 from same AR-1 to two different frogs which would never be crossed simultaneously?  Or for that matter splitting RT1 & RT2 with each output going to two or more frogs all of which would never be crossed simultaneously.  If this is possible and all runs are shorter than 10 feet from AR-1 the cost per frog would be cut drastically.  In any event, what would happen if two connected frogs were touch simultaneously: maybe the PWR-56 would just cut off power for 2 seconds and then one would move on?

Also there would be less wiring more like the Frog Juicer, rather than having 5 wires connected for each SmartFrog V5 which also looks like less expensive decent option.  Though retrofitting a Caboose 220S proved more messy for me than the SmartFrog V5 would be (I wired a SmartFrog V4, but it did not work).

Tom

[BruceRogers]

Tom,
That's a great question. If the train gods are in my favor today I should be able to give you your answer. I'm planning an arrangement just as you describe. I have 3 switches/frogs I'd like to connect to one AR-1 and several I'd like to have 2 frogs to one AR-1.
I see no reason why it won't work.

Update. I tested the the AR-1 to see how it performed switching current for multiple frogs that cannot be crossed simultaneously, in my case I connected 3. The frogs were all attached to one RT output and then both. The AR-1 worked perfectly switching polarity as needed. While one frog was occupied another locomotive was run into one of the other frogs. This caused the PWR-56 to short out as was expected. Removing one of the locomotives restored the power. By being able to switch polarity of one or more frogs will save me using 8 additional AR-1s.

[TwinStar]

Hmmm... inexpensive starting point:

https://www.ebay.com/itm/ICL8038-Function-Signal-Generator-Module-Sine-Square-Triangle-Wave-Output-Kits-S/401386381107?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160727114228%26meid%3D61d19766d757442cb4f60dd17abf03e3%26pid%3D100290%26rk%3D3%26rkt%3D4%26sd%3D201835571136%26itm%3D401386381107&_trksid=p2060778.c100290.m3507

For us electrical morons, is this square wave DC idea attainable? Or is this our perpetual motion machine?

[Alan]

For us electrical morons, is this square wave DC idea attainable? Or is this our perpetual motion machine?

I'm working on it. Few more days please.

[TwinStar]

For us electrical morons, is this square wave DC idea attainable? Or is this our perpetual motion machine?

I'm working on it. Few more days please.

Awesome. And please don't mistake my comment for any form of lack of patience or irritation. This would revolutionize my modeling world and I was just sitting here over morning coffee thinking 'big picture'. I can wait a year or more if the concept works.

[Dean]

I'm really confused. If the OP is using Electrofrog switches, why does he need any extra device to power the frogs?  They are already powered and change polarity when the switch is thrown. The only thing that is necessary is to install them properly. When I install them, neither the main or the diverging route is connected to rails leading from them. Only the throat lead gets powered from the tracks. They work perfectly.
No extra parts needed.

[Alan]

I agree there is no need for juicers with Peco Electrofrogs. I think the discussion wandered from there for the benefit of people using switches other than Peco Electrofrogs.

[Tom]

Bruce,

Thank you for running the experiment, greatly appreciated.  Ring just sold another AR-1.  I have several Caboose 220S throws so my options to fix frog problems are essentially unlimited.

Tom

[Alan]

Update. I tested the the AR-1 to see how it performed switching current for multiple frogs that cannot be crossed simultaneously, in my case I connected 3. The frogs were all attached to one RT output and then both. The AR-1 worked perfectly switching polarity as needed. While one frog was occupied another locomotive was run into one of the other frogs. This caused the PWR-56 to short out as was expected. Removing one of the locomotives restored the power. By being able to switch polarity of one or more frogs will save me using 8 additional AR-1s.

For people considering this application make damned sure your layout passes the quarter test everywhere, especially on the frogs, else you may shorten the life of your AR1s and/or melt feeder wires. The bigger the layout the more concerned you should be. It is one thing to flip polarity of a single frog located close to an AR-1, quite another to flip a power supply circuit breaker because of frogs located at a distance from an AR-1. Make sure your wiring is up to snuff.  Bruce's test confirms his is. Make sure yours is too.

[faithie999]

apologies for resurrecting an old thread, but it's easier than going through a summary of the context for my question.

for now, my layout will have a single power block, using a laptop-style 15v/5a power supply protected by a 5A Blue Sea marine/RV circuit breaker.

see post #80, page 6.  Tom installed one AR-1 to power several frogs, which he said worked as long as only one frog was crossed at a time.  has any discovery been made in the following couple of years that reinforces that as a viable solution, or disqualifies it?

I'm doing as much research as possible before starting to build my layout.  I have many atlas custom-line turnouts and shinohara (old version, I believe) curved turnouts and 3-way turnouts that I want to re-use.  the atlas's have isolated metal frogs with wiring connection points, and my Dremel and years ago I converted the shinohara turnouts to isolated frogs.

I think I would rather practice Alan's mantra of "clean track and powered frogs" rather than installing KA's in all my loco's.  I have a couple of LM-1's and LM-3s's on the bench ready to install, and then 20 or so more loco's to convert as the budget permits.

early in this thread (or in another old thread) Bill mentioned his "simple switch solution" but I can't find that on the PDC website so maybe that is lost to history.  my research says that the cheapest solution is Caboose 220S ground throws, although I'm intrigued by the ANE SmartFrog product but especially by the AR-1 solution to power multiple frogs.

please comment and advise.

thanks!!

Ken

edit--and if an AR-1 works with multiple frogs I would thing the SmartFrog ought to, as well.