Randy, thanks for the fine explanation!
Here's the deal with how it works - as a Frog Juicer, it's a SPDT electronic switch that connects the frog to either rail A or rail B as needed. According to the manufacturer, this won't work on DC, BUT it will also not harm the device. When usign a Frog Juicer as an autoreverser, you are combinign 2 of the frog outputs to make a single DPDT switch. This is a compeltely different electrical path within the device. Definitely won't work (as in reverse the polarity) with DC, same as pretty much ever other electronic AR device. But what happens when DC is passed through it? Potentially nothing, same as when it is used as a frog juicer. But what if you run the gaps and short it? DC power packs tend to be very slow to react to shorts - which is why minor things that don't stop DC locos, like the closeness of the frog rails on Peco Insulafrog turnouts, so cause shorting and stopping with DCC. The Hex Frog Juicer isn;t rated for very hgh current - remember, the primary intended purpose is powering frogs, where it is pretty much physically impossible to have more than one loco drawing power at a time, and even then it should only be for a tiny amount of time unless the loco is very tiny, in which case it would likely draw even tinier amounts of current. When used as an autoreverser, the current of whatever running in the reversing section is being fed through the Frog Juicer, the entire time the train is in the loop.
Long story short - while the manufacturer does say the Frog Juicer can be used as an AR device, long term it is probably not the most ideal solution excpet perhaps in N and smaller with very low current draw, or HO if using only newer locos, and then not if you regularly run 3-4 loco consists through the reverse section. And I would tend to avoid any sort of DCC automation devices with DC power to the rails.
However, Tam Valley should be able to help you. I've used several of their products, I've even talked directly to Duncan back when they were first getting started when I had an issue with an early version of one of their servo controllers.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I'd take Randy's opinion over mine on all things electrical, but perhaps feeding the rails DC through the juicer was too hard on it over time, as he suggests. It would be interesting what the manufacturer has to say.
Henry
COB Potomac & Northern
Shenandoah Valley
BigDaddy I think you can read it two ways. Used as a frog juicer, power would be fed to DC rails separately. Used as a reverser, they could have been more detailed.
I think you can read it two ways. Used as a frog juicer, power would be fed to DC rails separately. Used as a reverser, they could have been more detailed.
That sounds right--ambiguous wording that can be read two ways. And it looks like I might have picked the wrong interpretation.
DC runs through the frog juicer. No problems for at least a year and a half that way. And at least as I was reading the Tam Valley info, that didn't look like a problem.
SpringStreetBut further down that Tam Valley web page it says this: Will DC damage the frog juicer? No- although they will not power the frogs, they will not be damaged by DC so feel free to run your layout in DC mode with the frog juicers attached
Same question as ba&prr, When you run DC, are there separate track feeders or does the DC run through the juicer?
ba&prr When you have the switch set to DC, is DC going to the frog juicer? If so, you damaged it. Per Tam Valley: Please note - Frog Juicers are DCC (Digital Command Control) devices ONLY.
When you have the switch set to DC, is DC going to the frog juicer? If so, you damaged it. Per Tam Valley: Please note - Frog Juicers are DCC (Digital Command Control) devices ONLY.
But further down that Tam Valley web page it says this:
Will DC damage the frog juicer? No- although they will not power the frogs, they will not be damaged by DC so feel free to run your layout in DC mode with the frog juicers attached.
Randy, thanks for the idea. I just checked with a meter. The amperage draw of the PA is 1.4 to 1.5 for a second or so when it first starts, then drops to the .7 to .9 range. (It hasn't been run in a long, long time.) So yes, I'd wonder about that startup surge. However, according to the documentation the frog juicer works by sensing track current in excess of 2 amps (due to the short that occurs when the loco enters a wrong polarity frog or track section). The juicer then flips polarity in that >2 amp condition. So wouldn't it thus need to be able to handle 1.5 amp? (I also wrote to the manufacturer; we'll see what they think occurred.)
Thanks to all for the replies so far.
Gary
Just what vintage is that PA? Have you checked the current draw of it? It may be too much for the Frog Juicer - even though you weren't actually doing anythign that would cause it to need to flip the polarity, if you were running the loco on the reversing section then it was drawing its power through the Juicer.
Have you contacted Tam Valley?
This sounds like a device failure. They would probably like to test the unit to see what went wrong, and might even give you a new one for your trouble.
Back in the days of giant audio speakers, I had a pair of Bose 501s. One failed. The company was only a few towns away, so I took it back. They looked at it for an hour or so, told me it should not have failed, and gave me a new one.
It takes an iron man to play with a toy iron horse.
I'm trying to figure out what went wrong with my Tam Valley hex Frog Juicer. It gives a "short" indication as soon as it is energized, has no functioning outputs, and even just having it connected on the input side to my NCE Power Cab (with no connections to track) shorts out the power cab. Here are the details:
I have been using two pairs of the hex frog juicer outputs to control two reversing sections. One is a seldom used simple reversing loop. The other is for a crossover between the two sides of a loop. (Picture one end of a dogbone, with a crossover between the straight leads and the arc at the end of the dogbone as the reversing section.) I was using this latter "dogbone" section when the failure(s) occurred (though with the crossover lined for straight-through, non-diverging, non-reversing travel).
As mentioned, the DCC system is NCE Power Cab. I also use a DPDT center off switch to toggle to an MRC DC controller for occasional testing or break-in of a DC loco. I do not set up any reversing routes when on DC; basically I just run a big loop in that case. Tam Valley Depot's website specifically that frog juicers "will not be damaged by DC so feel free to run your layout in DC mode with the frog juicers attached." Turnouts in this part of the layout are mid-1990s vintage Atlas Custom Line code 100, #6.
This system worked fine for several years, with no changes. About six months ago, however, one pair of outputs to track (to the arc of the half dogbone/crossover section) simply went dead while running digitally (DCC). I could find nothing wrong with the loco, there had been no changes to track or wiring. Since I wasn't using the third pair of outputs on the hex juicer, I switched the track in question to the unused outputs, and everything was fine for a few months.
Next I had a weird problem (running DCC), again in the dogbone arc/crossover section. If I stopped a loco in that section, and turned off the system, when I would come back to the layout and turn on the system, the loco would not move, make sounds, etc. If I picked up the loco and put it on another part of the layout, everything was fine, and it would run through the reversing section just fine. This was annoying, but manageable.
Earlier this week, I was doing a quick test of a DC loco (a 1990s Life Like P2K Alco PA) to see how noisy it was. The crossover switches were lined straight, so I was basically running the loco in an ordinary loop, no polarity reversing. As it entered the reversing section, it slowed and eventually stopped dead. I'm pretty sure it had power for a second or two on entering the section, and then shut off and coasted a bit due to the flywheels. I tried it again, and this time it did the same thing. I removed the loco from the track.
But now nothing runs anywhere, because the frog juicer is showing a short indication and is shorting out whatever I have connected (the NCE cab or the MRC DC controller, whichever I've toggled to). The short appears to be in the frog juicer itself. If I disconnect the track leads from the frog juicer, it still shorts either control system, so the short isn't in or on the track. If I remove the frog juicer entirely from the system, everything works fine (except, of course, the now unpowered reversing sections).
So: I think I've got a failed hex frog juicer, and I've no idea why it failed. But I don't want to do it again with a new one. And so I'd appreciate any speculation as to what killed my frog juicer. Thanks very much.