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Capacitors in engines to handle dirty track?

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  • Member since
    April 2004
  • From: Ontario Canada
  • 3,574 posts
Posted by Mark R. on Tuesday, June 19, 2012 9:02 PM

Train Modeler

I use 24V, 1000ufd polarized capacitors on the  TSU Soundtraxx chips to improve the keep alive.   It works great.    I think their stock size is 220ufd.  Some require more work than others to improve.

I'll have to check out the TCS keep alive video, that is good news.

Richard

The factory capacitor that come with Soundtraxx are not "keep alive" capacitors to the motor. They are only "keep alive" for the sound circuit. This prevents the sound from cycling through it's start-up sequence if a slight power interruption is experienced. It has nothing to do with keeping the motor running.

Mark.

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

  • Member since
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  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Tuesday, June 19, 2012 7:12 PM

Check out the new TCS decoders with built-in Keep Alive circuitry.  I just received an e-mail announcement from them today announcing their new decoder series.

  • Member since
    March 2007
  • From: South Carolina
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Posted by Train Modeler on Tuesday, June 19, 2012 10:52 AM

I use 24V, 1000ufd polarized capacitors on the  TSU Soundtraxx chips to improve the keep alive.   It works great.    I think their stock size is 220ufd.  Some require more work than others to improve.

I'll have to check out the TCS keep alive video, that is good news.

Richard

  • Member since
    December 2004
  • From: Bedford, MA, USA
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Posted by MisterBeasley on Tuesday, June 19, 2012 10:14 AM

If dirty track is the problem, a CMX car may be a much better investment that installing capacitors.

It takes an iron man to play with a toy iron horse. 

  • Member since
    February 2002
  • From: Reading, PA
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Posted by rrinker on Monday, June 18, 2012 9:08 PM

The demo videos of the TCS keep alive looks to be every bit as good as the Lenz, and I've been very satisified with the performance of TCS decoders - they are my standard motor only installs.

                   --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    July 2006
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Posted by locoi1sa on Monday, June 18, 2012 8:04 PM

TCS and Lenz Gold decoders can have a keep alive system. The Lenz keep alive is incredible. I have seen an HO diesel loco go over a 3 foot section of dead rail on speed step 1 without stalling. But like anything else Lenz. It takes gold to buy it. 

           Pete

 I pray every day I break even, Cause I can really use the money!

 I started with nothing and still have most of it left!

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Monday, June 18, 2012 7:13 PM

 The small capacitors ont he motor leads are for RF supression, yet none of my locos without them has ever interfered with the radio or tv. Bachmann is famound for includign them, and they interfere witht he high frequency drive and BEMF sensing of good DCC decoders, and should always be removed.

 A keep-alive capacitor to keep the loco running is significantly larger and connects in a different way. However, it's not DCC makign the track dirty. Cleanign the track with any sort of oil or liquid other than somethign that evaoprates completely and quickly just invited dust to settle right back on the rails. Cleanign with abrasives is bad too, as you end up with pits and gooves in the rail that, you guessedit, collect dust. Clean wheels and clean pickup wipers are every bit as important as clean track. My current layout is in a spare bedroom, but my previous layotu was in an unfinished basement - I had bare cement floors and walls, and open floor joists above. In both cases, the only cleanign I've ever had to do is when painting the rails, I don;t even own a track clainign car at the moment, I cna;t justify the expense. It's been weeks since I last ran a rain, and it will run fine, no hesitations, if I go to the train room right now and fire up something. A good solid cleaning of the rails and ALL wheels - not just locos, but cars as well, should get things runnign fine. Use somethign a little aggressive - for the club layout we run acetone in a cleaning car - but this is a modular layout stored in trailers between shows, and half the issues with flickering headlights are caused by loose rail joiners on the connecting sections of track, not by the track being particualrly dirty.

 If all else fails, you cna add the capcitors to a DCC decoder, but this will generally void the warranty on them. Lenz and the newest TCS decoders have a facility to connect a power source after the fact, via a plug inmodule, if you have room for it in your locos.

                        --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
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  • From: US
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Posted by wp8thsub on Monday, June 18, 2012 6:56 PM

My old command control system, RailCommand from CVP Products, recommended using plain old 0.1 uf capacitors across the motor leads.  I've removed these as I've been converting to DCC.  On one locomotive, the capacitor was not readily visible and I missed removing it when changing decoders.  Once the loco increased to a normal operating speed the decoder blew.  After asking around online, and checking with Digitrax technical support, the consensus was that the capacitor was the likely cause of the decoder failure.

Rob Spangler

  • Member since
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  • From: Western, MA
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Posted by richg1998 on Monday, June 18, 2012 6:53 PM

Non polarized will not work. These capacitors are more for speaker crossover networks.

SoundTraxx started using a 39 ufd non polarized cap for isolating DC from the decoder to the speaker. The cap passes AC.

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.

  • Member since
    October 2006
  • From: Western, MA
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Posted by richg1998 on Monday, June 18, 2012 6:46 PM

cacole

If you were to try this you would have to use a non-polarized (NPO) electrolytic capacitor.  Getting a high enough Mfd rating to really do any good would mean that it is physically rather large, so space for it would be the biggest drawback.

If it was practical, I'm sure DCC dealers would have kits available by now.

Hate to rain on your parade but you do not just throw caps at a DCC loco to solve running issues. Go look at the below link. This guy is also very active in some Yahoo DCC Groups, SoundTraxx, for one.

He shares actual results.

Everyone, store the link in Favorites and do some reading.

http://www.members.optusnet.com.au/mainnorth/alive.htm

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.

  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Monday, June 18, 2012 6:05 PM

If you were to try this you would have to use a non-polarized (NPO) electrolytic capacitor.  Getting a high enough Mfd rating to really do any good would mean that it is physically rather large, so space for it would be the biggest drawback.

If it was practical, I'm sure DCC dealers would have kits available by now.

  • Member since
    April 2011
  • 79 posts
Capacitors in engines to handle dirty track?
Posted by JimInCR on Monday, June 18, 2012 5:50 PM

I am running DCC and am finding (like many others) that if my track is not meticulously clean I will get stalling of my engine.  It is usually a very small spot and sometimes the engine can even coast over it.  Assuming that the motor itself is still using DC power, rectified from the DCC 15V AC, it would seem that a capacitor across the motor leads might give enough juice to ride over small dirty spots and turnout frogs.  (And maybe add in a bit of momentum effect.)  Has anyone tried this?  If so what kind of capacitor?  I realize you could not use those blue polarized electrolytic capacitors that are so common because when you reversed your engine you would be applying reverse polarity to the capacitor resulting in an exploded capacitor.  (I learned that in my early electronic kit building days!)  I would be interested in hearing from anyone who knows more about this stuff than I do and has any ideas, pro or con, about this.  Thanks ahead of time.

Jim in Costa Rica

Modeling freelance Northern California late 1930s

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