Capacitors, keep-a-live etc.

[Carter]

Bruce Petrarca has an article in October 2017 MRH regarding "RailPro makes things easy". Also Bruce wrote an article past August 2017 in MRH regarding capacitors i.e. keepalive type systems.

Question? Will the same capacitor system (Keep-alive, Current keeper etc) he details in August issue work just the same in a DC powered or with the RailPro power supply.

Will capacitors (Keep-Alive etc.) be needed with RailPro?

Information needed.
Carter

[Alan]

Question? Will the same capacitor system (Keep-alive, Current keeper etc) he details in August issue work just the same in a DC powered or with the RailPro power supply.

[EDIT] No, capacitor systems for DCC will not work with RP.
[EDIT] I stand corrected. Thanks Bill. I accidentally confused our discussion about using the ground pin on LM3S modules.
[EDIT] DCC capacitor systems work only with LM3 and LM3S. Doing so may void the Ring Engineering warranty. See the thread below for fabricating a capacitor system for LM1, LM2. Thanks again Bill.

Will capacitors (Keep-Alive etc.) be needed with RailPro?

Yes, if you have dirty track, dirty wheels, dead frogs, etc.

Keep alive with RP is possible with a very simple home-built circuit. See this thread for a detailed explanation:
https://rpug.pdc.ca/index.php/topic,327.0.html

[William Brillinger]

I offer the TCS KA3 and KA4 on my website for use with RailPro.
They work fantastically.

http://pdc.ca/rr/catalog/product/railpro-and-accessories/51

It does not matter if you are on a DCC or RailPro DC powered layout.

Hopefully Ring Engineering will release their own Keep-Alive product soon.

[KPack]

You can also use DCC capacitor solutions (Keep Alive, etc) with the LM-2S and LM-2 modules, but you will need to install a bridge rectifier as well.  It's simple to do and I have done it with several of my old modules.  Works like a charm. 

You will notice the voltage to the module is lower with the bridge rectifier installed (Railpro allows you to monitor the voltage in real-time), but the difference is not much.  It does not effect operation between locomotives with Keep Alive and those without.  They can be MU'd and run together just fine.

-Kevin

[TwinStar]

You can also use DCC capacitor solutions (Keep Alive, etc) with the LM-2S and LM-2 modules, but you will need to install a bridge rectifier as well.  It's simple to do and I have done it with several of my old modules.  Works like a charm. 

You will notice the voltage to the module is lower with the bridge rectifier installed (Railpro allows you to monitor the voltage in real-time), but the difference is not much.  It does not effect operation between locomotives with Keep Alive and those without.  They can be MU'd and run together just fine.

-Kevin

I've got a BLI E8 with the LM-2S and KA leading a P2K E7 with an LM-2S and KA, followed by three head end cars, and then a P1K RDC with an LM-2S and no KA and they run together just fine.

[Alan]

I've got a BLI E8 with the LM-2S and KA leading a P2K E7 with an LM-2S and KA, followed by three head end cars, and then a P1K RDC with an LM-2S and no KA and they run together just fine.

Thanks to the magic of RP. Even with your RDC operating at 1.4V higher than the lead locos everything still works well. Isn't automated load sharing just the coolest thing ever? And it is voltage independent!!!

[Lee Nicholas]

After a few frustrating operating sessions due to poor running engines (RP is definitely more susceptible to dirty track) I tried a couple of keep alive products from Bill. WOW!! what a difference. So I made the executive decision (I get to do that) to install them in the entire fleet. I have 24 install so far with another 20 on order and another 20 after that. The install has been straight forward I use a bridge (from Bill) in the few LM2 and LM2S modules I have with no affect on performance and the rest are LM3S using the blue common and yellow negative again no affect on performance. I did reset the motor load on the LM2's per Tim.

I have visited with Tim numerous times about this subject and he is full of promise but no action to date. I told him I wasn't getting any younger and wanted to run trains not clean track hence my decision to move forward.

If you're on the fence try a couple I think you'll be surprised. I'm sure Tim will have them incorporated into a new module release  or as a stand alone product someday but I'm not willing to wait on this one.

Lee Nicholas 

[nodcc4me]

I can't blame you Lee. If you think dirty track is a problem on RailPro powered layouts, you should try it on DCC powered layouts. I was getting to the point where I almost didn't want to bring my locomotives to the club anymore because a good wheel cleaning was needed after each use. The problem is not nearly as bad though on my RP powered home layout. Still, I also have hopes that Tim will come up with a solution in the near future, though I'm not counting the days.

[KPack]

Lee, glad to hear you went to keep alive's.  They certainly make running much more enjoyable!  The only struggle I've had is trying to find adequate space to fit them in some locomotives, but that is mostly because I'm using multiple speakers inside the shell (they take up a lot of space).

Tim's been talking about building his own keep alive for a while using mostly SMD components, but I imagine there is a lot that goes into designing and manufacturing something like this.  I'm sure most of his attention has been taken up with the recent update and sound editing.  Hopefully he gets some more prime mover recordings out soon.  I know he has several new ones to work with.

-Kevin

[Alan]

The real space eaters are the super capacitors. At present there is no technology for smaller versions of such. Capacitance is all about surface area and distance between plates. Super caps (or more correct, ultra capacitors) are essentially double sided regular electrolytic capacitors with the plate spacing at the bare minimum. There are only two sides to a plate so nothing further to be gained there. And with spacing already down in the 3 to 5V range, there isn't much more to be gained from closer spacing - operating voltage drops as plates get closer. So, without some radical new technology super caps have probably reached their limit in miniaturization.

[MtRR75]

The real space eaters are the super capacitors. ........... So, without some radical new technology super caps have probably reached their limit in miniaturization.

One of the advantages of running steamers.  All that space in the tender to work with.

[Alan]

One of the advantages of running steamers.  All that space in the tender to work with.

One of the advantages of keeping track clean and powering your frogs. No caps needed.

Yes, yes I know about club layouts. But for your home layout do yourself a big favor. Power your frogs, drag a masonite block occasionally, and be done with it. Attention cap lovers - you do realize that if you park your loco on a spot that otherwise requires a cap to get across then the loco is not going to start back up when you want to move it again. The cap will continue discharging itself into the module while parked. Once the cap drains below 10V the module will shut off and you will have no choice but to use the 0-5-0 to get the loco moving again.

[William Brillinger]

This is Tim Ring's mantra too. "One of the advantages of keeping track clean and powering your frogs. No caps needed." And it's why he has not released a Keep-Alive of his own yet.

I'm sorry, but it's just not realistic. You don't run sound units so you're in a whole different world Alan. Keep-Alives add just enough juice to assist with the little gotcha's that sneak up on you and ruin an op session, especially when you take your motive power to another persons layout.

It's like a having a UPS on your computer. It just smooths out the blips.

[Alan]

Bill, I get the 'other people's layout' part. Caps make perfect sense in that case. And if your power finds it way onto other layouts frequently then by all means cap'em all. In the paint manufacturing business we have a saying - make the paint as dirty as the surface being painted. Perhaps you have heard of a paint additive called fish eye eliminator? It is the keep-alive equivalent for paint. It is recommended only as a last resort.

But I respectfully disagree about life on your own layout, sound or not. Case in point... watch the headlight LED in the below video. It is just as sensitive to drop out as sound would be. Perhaps more so. Sound has at least a tiny amount of capacitance in the amplifier circuit. LEDs have none. Do you see the LED ever blink during the whole run? Those familiar know this is a video of the first end-to-end run on my completed upper deck track work. However, that does not mean it is brand new track. Far from it. The track laying process took over a year and a half during which many trains were run both for testing and for fun. There were a whole lot of hours already on the track when this video was shot. Shucks, the track was 5 years old in the box by the time I laid it.

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Don't get me wrong. I am not saying caps are bad. I merely caution people reading these threads about using them as a substitute for proper track installation, wiring, and maintenance on their own layouts. Our little locos are cramped for space as it is. Modern 6 axle and steam may have the space. What about your switchers? Ever tried to put a LM inside an Alco S2? It is an extremely tight fit. And there is no weight to mill for additional space. Absolutely no space for a block of caps. So, if you rely on caps what do you do when the little switcher can't make it across the spot? You are screwed. I am just trying to encourage people to spend the time taking every possible precaution outside the locomotive before they start stuffing a solution inside the loco. Quality trackwork, a wire to a frog, and a cloth across the track works for every loco on your layout, cap or no cap.

[William Brillinger]

I am just trying to encourage people to spend the time taking every possible precaution outside the locomotive before they start stuffing a solution inside the loco. Quality trackwork, a wire to a frog, and a cloth across the track works for every loco on your layout, cap or no cap.

That's a fair point Alan. In my case I was screwed before I started. I had a plethora of old Peco Insulfrogs on hand and I didn't know any better until my track was all down. Wired frogs are not an option for me. If there is a next time, it might be different.