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Keep-alive caps for TSU-750 - smallest one with an effect?

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  • Member since
    November 2005
  • From: Phoenix, AZ
  • 693 posts
Posted by woodone on Tuesday, March 29, 2011 3:14 PM

Try using the surface mount capacitors. They are very small. At 100uF you can tie them together and make a 400uF cap if you use four. Some times you can find room for two surface mount caps in one end and two more some where else. Just wire them in parallel. If you have more room add some more.

  • Member since
    June 2009
  • From: QLD, Australia
  • 1,111 posts
Posted by tbdanny on Monday, March 28, 2011 8:25 PM

Elmer, Randy and Rich,

Thanks for the replies.  I'm already adding extra pickups to the tender (loco already has them).  I'm just trying to squeeze every last drop of reliability that I can get out of this locomotive.

Cheers,

tbdanny

The Location: Forests of the Pacific Northwest, Oregon
The Year: 1948
The Scale: On30
The Blog: http://bvlcorr.tumblr.com

  • Member since
    October 2006
  • From: Western, MA
  • 8,571 posts
Posted by richg1998 on Monday, March 28, 2011 8:15 PM

Here is more info about keep alive.

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

Litchfield Station sells SMD caps which might be a little smaller.

All wheel pickup on the tender and loco and clean track solves a lot of issues. When I say clean, not looks clean but you have actually done the cleaning process.

Most want as much capacitance as possible.

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
    February 2002
  • From: Reading, PA
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Posted by rrinker on Monday, March 28, 2011 8:12 PM

 I would have to agree, 320uF is significantly more than 220uF An investment in additional pickups would probbaly give more dividends - if there are pickups spaced nearly the entire length of the engine and tender then even a small loco would span a large number dead frog and if your track is reasonably clean shoudl never ever stall or have the sound cut out.

                            --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
    January 2007
  • From: Eastern Shore Virginia
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Posted by gandydancer19 on Monday, March 28, 2011 6:45 PM

As an old electronics technician, I would say Yes.  Make sure the polarity matches.  Plus to plus and minus to minus.  You want them to be in parallel.

Elmer.

The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.

(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.

  • Member since
    June 2009
  • From: QLD, Australia
  • 1,111 posts
Keep-alive caps for TSU-750 - smallest one with an effect?
Posted by tbdanny on Monday, March 28, 2011 6:40 PM

Hi all,

I'm in the process of wiring a keep-alive capacitor into a TSU-750 I've installed in a HOn3 brass C-25 locomotive.  I've had to put the 220uf capacitor that came with the decoder on the outside (under the chassis, disguised as a brake cylinder), but I have space for a smaller capacitor in paralell with it inside the tender - this would have to be smaller.  My question is would the extra 100uf (I think this is the biggest that will fit in) make a difference in terms of keeping the decoder alive over trouble spots?

Thanks in advance,

tbdanny

The Location: Forests of the Pacific Northwest, Oregon
The Year: 1948
The Scale: On30
The Blog: http://bvlcorr.tumblr.com

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