They do not work on DC. No way to charge them up. DCC has full voltage on the rails at all times, even when locos are stopped. Plus at the point the keep alive connects, the polarity never changes. The capacitors used for keep alives are polarity sensative - in fact they can explode if polarity is reversed.
Only real option for DC is to power the frogs and keep the track, wheels, and pickups clean.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
How will / do Keep Alives work on DC, no sound just plain vanilla engines?
God's Best & Happy Rails to You!
Bing (RIPRR The Route of the Buzzards)
The future: Dead Rail Society
Dante:
Your post reminded me that I had to remove the flywheels in my switchers to make space for the Keep Alives. I did have the same results. They ran perfectly!
Interestingly, the drives I used were from Hollywood Foundry in Australia. They are called 'BullAnts' and they are very nicely built. I asked the owner, Geoff, about removing the flywheels before I did it and he initially advised against it. None the less, I decided to take the plunge as it were. The results, as I said above, were impressive.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
I have a vintage Varney Docksider 0-4-0 in which I previously installed a NWSL can motor and ran it occasionally using the DC option of my Zephyr Xtra. Not all my frogs are powered (some connected to Frog Juicers and some power-routing), and the short-wheelbase stalled the loco in certain places.
So I removed the flywheel, making space in the cab for a TCS KAM4 that includes a KA2 Keep Alive, the entire decoder being very compact. The Docksider now runs like never before, gliding through all the turnouts, running very slowly and accelerating and decelerating smoothly. If you can fit it in, by all means go for it.
Dante
Jim,
Decoders (like TCS KA series) that have keep-alive capacity work great. I have one in a Bowser PCC trolley. Even if power to the tracks is completely shut off, it will continue to operate (with lights on) for 3-5 seconds; far more than enough to cross any unpowered turnout frog, crossing, or section of dirty track one might have.
The keep-alive modules also work quite well but their size (depending on how much capacitance you are wanting) is generally prohibitive for smaller locos like diesel yard switchers. Thankfully, companies like TCS have the specific physical dimensions (L x W x H) for all their decoders and keep-alive modules listed on their website. That's helpful for making better informed choices as to whether a given decoder is going to fit under the shell of your specific locomotive or not.
It still may require you to remove some interior cab detailing or modify the chassis in some way. I usually try to avoid that at all costs but have had to on a couple of occasions - e.g. my Walthers SW1 switcher.
Jim, let us know what you end up doing.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Docjmp I have been having problems with a couple of my locos, primarily a BLI EMD switcher, loosing power and then starting again spontaneously, or needing a "nudge". I visited my local train store this weekend and asked about the possible causes. Since I took two of the locos in with me, they were able to test on their track. Part of the problem was that I needed to clean the wheels. They also suggested I consider adding a Keep-Alive capacitor. When I researched them online, I found there are 2, 4, and 6 post products. How do I determine which one to use and what are your thoughts on the Keep-Alive. They would greatly reduce the frustration I experience by having my smaller locos stop frequently (even when I have cleaned the track and the wheels). Jim
I have been having problems with a couple of my locos, primarily a BLI EMD switcher, loosing power and then starting again spontaneously, or needing a "nudge". I visited my local train store this weekend and asked about the possible causes. Since I took two of the locos in with me, they were able to test on their track. Part of the problem was that I needed to clean the wheels. They also suggested I consider adding a Keep-Alive capacitor. When I researched them online, I found there are 2, 4, and 6 post products. How do I determine which one to use and what are your thoughts on the Keep-Alive. They would greatly reduce the frustration I experience by having my smaller locos stop frequently (even when I have cleaned the track and the wheels).
Jim
I have two of those and yes they are a problem if you have insulated frogs on your turnouts. I also have similar problems with my BLI K-2 Pacific. I started a thread early this year and that's when I learned about keep-alive technology. Some suggested the solution is to power the frogs but with the number I have in my large classification yard, the keep-alive solution seems to be my far the simplest and cheapest solution. I didn't have a chance to install them before spring came ending the model railroading season for me, but all the feedback I got on them was positive. It is definitely going to be a priority item as I am just now getting back into the model railroading for the fall and winter.
Sorry for the late reply. I prefer the KA2 if it will fit even if I have to do some mofiying to the chassis. I have had some KA1's fail after a while. They were quickly replaced by TCS but the KA2's and Current Keepers are much more reliable and have significantly better reserve power in my opinion.
Marty C
I have installed a keep alive in all of my locomotives in HO and On30. All of my decoders are Tsunami and the keep alives are a mix of KA1, KA2, and Current Keepers. I am equally pleased with all 3. Which one I use depends on the space available in the locomotive as they are all shaped differently. A keep alive and graphite treatment makes track cleaning almost uneeded for me.
Hi Marty,
If the space is available, do you prefer the KA1 or KA2? I like the size of the KA1 but wonder if the 2-5 seconds is long enough.
I have added commercial Keep Alives (TCS KA1's and 2's and Current Keepers to most of my dcc locos and they have measureably improved the operating of the loco. They virtually eliminated stalling on switch frogs and have significantly decreased the amount of time spent cleaning wheels and track. However, they do not eliminate the need to clean nor do they eliminate the need to still do good track work. Connecting them is fairly straight forward if you have soldering skills. The biggest challenge is often finding room in the shell to fit them in. Some people say they are a crutch but I have found them to be a simple way to improve the enjoyment of operating the layout.
Hi Jim:
I have put Loksound Power Pack keep alives in two of my very small switcher locomotives. The improvement in reliability was impressive. In fact, they never stall at all vs the pre-keep alive performance when, if they crossed over a turnout without stalling, that was a small miracle.
I strongly recommend finding the space to install keep alives, even if you have to lose some weight doing it. They will do far more for reliable performance than any amount of dead weight will.
Cannot answer for that loco but here is a lot of info about stay alive. Usually a series of super caps in with a resistor and diode. I think one brand has a zener. Not sure.
http://www.members.optusnet.com.au/mainnorth/alive.htm
The stay alive has two wires. Positive and negative that connect to the plus and minus output of the full wave bridge rectifier. The pictures and explanation are quite clear.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Even when I had my track at its cleanest and loco wheels also, my HO Genesis GP9 (but not my BLI NW2) was the one that would soonest act up over my least well done trackage, a triple 90 degree crossing series with minimal intermediate connecting rail extensions. Not as smooth as it should be. Rather hard to re-do with everything connected from 8 closely connected approach tracks. I made it somewhat better with some filing but not trouble free.
This loco had my least favorite decoder, a factory Tsunami where the horn and speaker combo were not to my liking. So when I decided to change the decoder (to a LokSound Select) I improved the speaker (dual sugarcubes were better than the original oval), and (to the point of this subject) I tried the new setup with some add-on capacitance. I noticed the LokSound Select manual showed how to connect capacitors to the various Select types. Mine was a Direct (circuit board) subtype, and I called ESU to be sure to know exactly where to connect (to some really teeny spots). Rather than try the Current Keeper or Keep Alive modules, which are not small to fit in a GP9, I decided to try some single capacitors (from Radio Shack). I tried several sizes, each larger, until any sound hiccup was eliminated on pretty clean track (clean wheels of course). I turned out that a 1000 microFarad cap did the trip for this case, about 1/3 the size of a AAA battery. The next smaller was inadequate and the next bigger (2200) was much larger to fit in. Other locos have been fine so this was a case of being fortunate because it fit in the cab but a larger one or the other commercial model RR types, requiring more room, would have required more room (smaller speaker and/or decoder room probably required, or milling the weight more radically). The other locos I have cntinue to do ok at this trackage, so I'm lucky it worked ok with a single moderate size cap for this particular case, and not get into having to attack a large percentage of locos.
So I'd say, priority one is to install track well and keep track and loco wheels reasonably clean. After that, capacitors can make sense in some cases. I think I was lucky my one most finnicky loco responded with a single moderate size capacitor. If it hadn't worked, I'd have probably figured out how to add a larger one / set. Most locos should not need capacitor add-ons IMO, unless the environmental conditions are unusual. And it depends on whether a DC hesitation problem, a DCC motor hesitation problem or (most noticeable in my case) a DCC sound interruption (hiccup) that is very noticeable.
Please advise whether you are using DCC and sound, as that makes a difference in sensitivity to weaknesses. And did the LHS advise how the capacitor module would be fit into available space?
UPDATE: I just came across the following from 2014. If I read it right, I may not have used the best type (high density "super capacitors") with the Radio Shack. This suggests the RR types use a much more space efficient type? Not so sure about the type I used.
https://sites.google.com/site/markgurries/home/decoders/keep-alive-compatibility
Paul
Modeling HO with a transition era UP bent