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Keep alive install.

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  • Member since
    October 2022
  • 8 posts
Keep alive install.
Posted by Dr_Bullitt on Thursday, October 27, 2022 3:57 PM

Can a keep alive be used on a DC only locomotive?

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Posted by Steven Otte on Friday, October 28, 2022 8:59 AM

No. A DC locomotive's speed is controlled by varying the voltage to the motor. A keep-alive's purpose is to maintain constant voltage to the motor. If you installed one, you wouldn't be able to control the locomotive's speed, as the keep-alive doesn't know the difference between a section of dead track and the operator's intent to stop the locomotive.

--
Steven Otte, Model Railroader senior associate editor
sotte@kalmbach.com

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  • From: lavale, md
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Posted by gregc on Friday, October 28, 2022 9:27 AM

you could use a large non-polarized capacitor if you could find one.   

many keep alives use smaller super-caps that are polarized and have capacitor ratings > 1F.

Steven Otte
If you installed one, you wouldn't be able to control the locomotive's speed, as the keep-alive doesn't know the difference between a section of dead track and the operator's intent to stop the locomotive.

just to be clear, a keep alive provide power until it is drained and if it is draining because of dirty track, no DCC commands are being received and the operator has no control of the loco

greg - Philadelphia & Reading / Reading

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Posted by mvlandsw on Friday, October 28, 2022 1:29 PM

I wonder if an inductive pickup could be arranged to receive DCC commands without depending on conductivity through the wheels.

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Posted by BroadwayLion on Friday, October 28, 2022 2:36 PM

DIDN'T WORK

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by jjdamnit on Friday, October 28, 2022 3:30 PM

Hello All,

mvlandsw
I wonder if an inductive pickup could be arranged to receive DCC commands...

The OP is asking about DC, not DCC.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

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Posted by snjroy on Friday, October 28, 2022 4:26 PM

On DC, only mechanical solutions exist for that: flywheels, double-heading and clean track Smile.

Simon

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    April 2021
  • From: saskabush
  • 127 posts
Posted by wvgca on Friday, October 28, 2022 7:26 PM

well, in a way, yes ...

but .. the keep alive [depending on the capacity / size] would function more as a 'momentum' controll ...

it's a lot easier to use flywheels or other mechanical means ..

and yes, i tried it, and it didn't work very well .. plus the keep alive [for a DC loco] would be constructed differently than one for a DCC loco, as far as i know, all the commercial offerings are for DCC not DC

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