TCS N Scale Keep Alive

[John]

Larry Pucket video shows how he uses the TCS KA-N1 small Keep Alive decoder with an HO Soundtrax decoder . it's pretty impressive ..

https://www.tcsdcc.com/product-page/ka-n1

[peteski]

To me anything smaller that few hundred thousands of micro Farads is not a real keep alive. But even at 900 µF, it will prevent decoder reboots during very brief interruptions of power. A real keep-alive to me has to power the model for a second or more.

KA-N1 basically is what many members here make themselves by just adding few tantalum caps to the decoder.  Still, it's convenient ad tot too pricey for those not wanting to roll their own.

[John]

To me anything smaller that few hundred thousands of micro Farads is not a real keep alive. But even at 900 µF, it will prevent decoder reboots during very brief interruptions of power. A real keep-alive to me has to power the model for a second or more.

KA-N1 basically is what many members here make themselves by just adding few tantalum caps to the decoder.  Still, it's convenient ad tot too pricey for those not wanting to roll their own.

I think the video shows a good capability, one that could serve nscalers well ...  I agree its not going to run your engine for 10 seconds, but could provide enough power to not reboot your sound decoder every time it hits a spot of dirt or a dead frog  -- it's also smaller than the similar iowa scaled engineering device

[Rasputen]

I've fitted one to an Atlas S2 with factory Loksound, it runs great!  I must admit I never ran it without the keep alive.

[nickelplate759]

sounds like just the thing to cram into my BLI PAs, if I can figure out where to attach it.

[peteski]

I think the video shows a good capability, one that could serve nscalers well ...  I agree its not going to run your engine for 10 seconds, but could provide enough power to not reboot your sound decoder every time it hits a spot of dirt or a dead frog  -- it's also smaller than the similar iowa scaled engineering device

For N scale (due to size limitation) I would not expect a small size keep alive to keep the model running anything even close to 10 seconds. Like I mentioned, IMO 1-2 seconds would go far towards keeping the loco going slow over insulfrog turnouts.

I installed home-made keep alives in my friend's Bachmann 44-tonner and in Atlas S-2 with Loksound.  If I recall, those are less than 500µF each, and they did improve running reliability.

[milw156]

For N scale (due to size limitation) I would not expect a small size keep alive to keep the model running anything even close to 10 seconds. Like I mentioned, IMO 1-2 seconds would go far towards keeping the loco going slow over insulfrog turnouts.

I installed home-made keep alives in my friend's Bachmann 44-tonner and in Atlas S-2 with Loksound.  If I recall, those are less than 500µF each, and they did improve running reliability.

So, what does TCS have on the Bachman Charger decoder board that will keep it running for at least 3 seconds after picking it up off of the rails? I have not had the Bawls to take mine apart

[peteski]

So, what does TCS have on the Bachman Charger decoder board that will keep it running for at least 3 seconds after picking it up off of the rails? I have not had the Bawls to take mine apart

Charger has lots of room inside that shell. Bachmann has a "real" Keep-alive unit inside.  Humongous Multi-Farad  capacitors.  Think TCS KA2, or even larger.  Here is a photo from http://spookshow.net/loco/bachsc44.html



The large 4 cylinders on the left side of the decoder board are the Keep-alive.

[jdcolombo]

FWIW, I've found that 400uf in a modern N scale diesel will keep the decoder from rebooting as long as the wheels and track are modestly clean.  It will not provide any real "keep alive" as Peteski notes - just enough to keep the sound on during micro-second electrical interruptions, which we all have regardless how clean everything is.

I consider the TCS KA-1 the smallest useful "real" keep alive.  I use it in my steam locos, and it will keep an N-scale Berk or Mike running for about 2 seconds if fully charged.  I think these are essential for steam sound installs in anything smaller than a Challenger or Big-Boy (where all the weight and pick-up wheels usually make for extremely good electrical contact).  Kato's FEF also is solid because of the sprung driver design.  Everything else is iffy - including my Key brass Berkshire, which has a ton of weight, but is electrically challenged.  Fortunately, the KA-1 is small enough that it will fit in nearly all steam tenders - I've squeezed one into a Kato Mike tender and a Bachmann 10-wheeler along with an ESU LokSound Micro and an 8x12mm speaker . . .

John C.

[GaryHinshaw]

I have now converted something like 25 of my Kato units to a /LokPilot 5 Micro+KA-N1/ combo* (no sound for me, thanks) and the results are amazing.  Silky smooth, stall-free performance without needing to clean the track thoroughly every week or two.  I can even run distributed power under one throttle without too much concern.  And the KA-N1 is small enough that I don't need to modify any loco frames.  Maybe not a true keep-alive, but definitely a keep-happy.   

https://www.therailwire.net/forum/index.php?topic=56681.msg783872#msg783872

[Lemosteam]

What would happen if someone were to add two KA-N1 in there?  Would that improve the time?

[peteski]

What would happen if someone were to add two KA-N1 in there?  Would that improve the time?

2 in parallel. Yup.