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Keep alive device, worth it?

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  • Member since
    May 2004
  • 7,500 posts
Posted by 7j43k on Sunday, June 20, 2021 11:18 PM

JDawg

Actualy, my progect involves that teeny little Switcher.Big Smile I know that i will need some sort of power capacitor for the model, it's just that the KA2 takes up valuable space in the unit.CryingBang Head Could I just sub out the 220uf for, say, a 10k+ uf? I can't think of a reason that wouldn't work. It would take some time to charge up, but other than that...Confused

 

 

Here's the loco I'm talking about:

 

 

 

Then I guess you got the DC version.  I think you're up a crick.  My best advice is to find a DCC version, and buy it.  It comes with "keep alive" already installed.

 

 

Ed

 

  • Member since
    September 2020
  • 432 posts
Posted by JDawg on Sunday, June 20, 2021 10:33 PM

7j43k

 

 
JDawg

Could I just use a larger capacitor? It comes with a 220 UF, would a larger capacity device harm the decoder? My *ahem* Limited electrical knowledge informs me that I can swap out, but my self doubt argues otherwise. 

 

 

 

The small ESU Power Pack (capacitor) has 1,000,000 uF.  Quite a bit bigger than 220, I would say.

I think "keep alives" are great.  I've put them in a couple of locomotives and a couple of passenger cars.  I will definitely do more.

 

The positives are self-evident (if not, see Walthers teeny little switcher crawl over paper towels).

The negatives are:

You have to pay money to get one.

You have to know how to install it.

You have to have room to fit it in.

 

Ed

 

Actualy, my progect involves that teeny little Switcher.Big Smile I know that i will need some sort of power capacitor for the model, it's just that the KA2 takes up valuable space in the unit.CryingBang Head Could I just sub out the 220uf for, say, a 10k+ uf? I can't think of a reason that wouldn't work. It would take some time to charge up, but other than that...Confused

JJF


Prototypically modeling the Great Northern in Minnesota with just a hint of freelancing. Smile, Wink & Grin

Yesterday is History.

Tomorrow is a Mystery.

But today is a Gift, that is why it is called the Present. 

  • Member since
    May 2004
  • 7,500 posts
Posted by 7j43k on Sunday, June 20, 2021 10:25 PM

JDawg

Could I just use a larger capacitor? It comes with a 220 UF, would a larger capacity device harm the decoder? My *ahem* Limited electrical knowledge informs me that I can swap out, but my self doubt argues otherwise. 

 

The small ESU Power Pack (capacitor) has 1,000,000 uF.  Quite a bit bigger than 220, I would say.

I think "keep alives" are great.  I've put them in a couple of locomotives and a couple of passenger cars.  I will definitely do more.

 

The positives are self-evident (if not, see Walthers teeny little switcher crawl over paper towels).

The negatives are:

You have to pay money to get one.

You have to know how to install it.

You have to have room to fit it in.

 

Ed

  • Member since
    August 2003
  • From: Collinwood, Ohio, USA
  • 16,367 posts
Posted by gmpullman on Sunday, June 20, 2021 9:28 PM

I believe the original Soundtraxx decoders came with the small cap that was to "buffer" the sound amplifier only.

"Keep Alive" provides a small amount of power capacity for the entire decoder, sound, lights and motor in order to provide a bit of "standby" power to bridge a short power interruption from the power supplied by the rails/wheels.

I generally resort to keep alive as a last resort if I have a particular locomotive that has been showing stuttering and I'm sure that all the other options have been exhausted (read, powered frogs, good points, clean wheels, suitable current collection on the locomotive).

Some of my brass engines benefit from keep alive due to the fact that even the longer ones pickup the one rail from the engine and the other rail through the tender. 

There's a tradeoff with the length of keep alive time available vs. size of capacitor and total current draw of the motor, amp and lights, if applicable. In most cases it will cure an interruption of two or three seconds — sometimes a bit longer.

Good Luck, Ed

  • Member since
    September 2020
  • 432 posts
Posted by JDawg on Sunday, June 20, 2021 7:47 PM

Could I just use a larger capacitor? It comes with a 220 UF, would a larger capacity device harm the decoder? My *ahem* Limited electrical knowledge informs me that I can swap out, but my self doubt argues otherwise. 

JJF


Prototypically modeling the Great Northern in Minnesota with just a hint of freelancing. Smile, Wink & Grin

Yesterday is History.

Tomorrow is a Mystery.

But today is a Gift, that is why it is called the Present. 

  • Member since
    September 2020
  • 432 posts
Keep alive device, worth it?
Posted by JDawg on Sunday, June 20, 2021 7:38 PM

Soundtraxx decoders come with an optional capacitor. I've always included it on installs, but on my most recent project, I'm considering swapping it out for a keep alive. Is it worth it? How much power will the included capacitor provide vs the KA. I'm not going for any records, only 2-3 seconds, just enough to cross a switch frog. Thoughts?

JJF


Prototypically modeling the Great Northern in Minnesota with just a hint of freelancing. Smile, Wink & Grin

Yesterday is History.

Tomorrow is a Mystery.

But today is a Gift, that is why it is called the Present. 

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