Model Railroaders have been faced with the quandry of switch frogs for decades.
Electro-frogs, energized frogs, Insul-frogs, dead frogs, frog polarity, power routing, frog juicer...
Recognize any of those phrases?
The first question when selecting and installing a switch is always whether to energize the frog or not. A live frog is always better than a dead frog because model trains require a smooth, consistent flow of electricity to perform well.
It has been a known problem since the first switch was fabricated that an energized switch frog must change polarity based on the orientation of the switch points.
I won't digress into that subject here. Please review the DCC Wiki on Turnouts for more information on the issue.
The introduction of DCC has only compounded these issues since DCC decoders do not respond well to interruptions of flow of electricity to the processor.
The best way to solve the problem is to use any one of a thousand techniques to route power to the frog directly from the track bus.
Unfortunately this can get complicated both mechanically and electrically and not everyone want to fool with it.
Another solution is to install a keep-alive device on the decoder which acts like a Uninterrupted Power Supply for a computer when the decoders looses power directly from the rail.
This is a nice fix and I am a big fan since the Keep-Alive hides a lot of nuisance issues and really does make DCC-equipped models run better but... keep-alives are very large and not every model or scale can incorporate them.
A third option is the Tam Valley Depot Frog Juicer.
The Tam Valley Depot Frog Juicer is a DCC accessory developed to simplify the task of energizing the frog AND set frog polarity with minimal effort.
It is essentially a simplified DCC auto-reverser.
Installation is quick and easy (it takes about five minutes), they require very little long term maintenance and they are very reasonably priced.
Faster, better, cheaper... an engineers mantra.
