Frog juicer for multiple frogs?

[Scottl]

I've been doing some electrical planning for block detection and other matters, and I was thinking about my last four turnouts that still have unpowered frogs.  I use a hex frog juicer for the other six and it works great and I have assumed I will need a second juicer to complete the rest.

But then it occurred to me that there is no electrical reason (that I can think of) why two frogs can't share the same juicer circuit.  The current won't exceed the limits and in theory, you could have an infinite number of frogs on the same circuit as long as only one was actively being traversed by a "circuit" like a locomotive.

Of course, what can't happen is have two different conductive circuits (loco or a resistive wheelset) on the respective frogs at the same time and travelling in different directions.  Is there any other reason to avoid this?

On a layout like mine where one train is running at a time, the odds of shorting both frogs at the same time is very slim, unless I used a rear DPU or similar.

Thoughts?

[GaryHinshaw]

I think your reasoning is correct.  You just need to avoid having two frogs being traversed at the same time that require opposite polarity.  If you decide to go with resistive wheels at some point, ensuring that condition might become difficult.  Of course you have some perfectly good contacts on your Tortoises that were designed for this very task...

[peteski]

Of course you have some perfectly good contacts on your Tortoises that were designed for this very task...

And they are absolutely free (included in the price of the switch machine). 

[Scottl]

There is a frog wire that goes all the way back to the panel and is sitting there unused already, so I could double up the juicer with a screwdriver in a minute.  Sometimes the most complicated solution is the easiest 

Good point about resistive wheel sets...

[peteski]

Unless you are absolutely certain that  no loco or a piece of rolling stock with metal (not just resistive) wheels will travel through both frogs at the same time then to me you are asking for trouble.

When standard metal wheels cross the gap between the frog and the rail adjacent to it, the wheel tread will short them together causing the juicer to match the polarity.  If you have 2 trains traveling through both switches at the same time you can potentially end up with the juicer being flipped back and forth as every wheel travels through each gap at the frog.  If the wheels from both trains cross both gaps at the same time, you have a short.

I guess the Juicer and/or booster will shut down and recover, but to me that is not a good design.

[GaryHinshaw]

I agree that straight metal wheels are also problematic.  If it were me, I would just use the Tortoise contacts (or a separate juicer) so I don't have to keep thinking about operational restrictions.  A year from now you may well have forgotten which frogs are ganged and then find yourself wondering why the layout is giving you problems.

[Scottl]

You are both right.  Thanks for the input.  It seemed like a good idea at the time.