Search The Inn

Sunday, March 27, 2022

Installing Keep Alives On Just About Any Decoder (+Making Them)

<Author's update 2024-09-25>

Unfortunately, the link given in the below paragraph is no longer active (thanks for letting me know Don). This link shows instructions on making your own Keep Alive with various references to the parts, etc. (from the June 2019 issue of Model Railroad Hobbyist Magazine). An article on identifying the negative ground for a decoder is in this May 2019 issue.

An excellent web page on installing keep alive on just about any decoder is located here. It is a very comprehensive list. Also, in the article are instructions on making your own Keep Alive with various references to the parts, theory, etc.

One thing stated in the original article that this author disagrees with in certain circumstances is the statement:

 Note: Disable DC operation in CV 29 & set CV 11 to “0”, when using Stay/Keep Alives.

The setting of CV 11 to 0 allows the locomotive with the keep alive to continue in motion with sound as long as the keep alive has the power to do it. There are times when this may not be a good thing. The module model railroad club the author belongs to has a "lift bridge" as one of their modules. This allows members to enter and leave the layout without having to crawl under a module (remember, you will age). When the lift bridge is raised, power is cut to the modules on either side of it. This prevents approaching engines from taking a trip to the concrete (usually for the last time). With a keep alive installed it will continue to run! 

CV 11 controls how long the engine will continue to run regardless of the power left in it. Usually, the value in CV 11 is measured in 1/4 seconds so, for example, a value of 12 would equate to 3 seconds. The author usually sets CV 11 to this value of 12 in all his locomotives. This just about guarantees none of them come to a untimely end. 

Check your decoders' documentation to determine the appropriate value for CV 11.


  • If you have an idea for a blog post here, let me know. If I can comment on it, I will or I'll see if someone else can and post it

3 comments:

  1. Just came across your blog and I’m slowly read through them. Nice work. This article link dealing with KA’s is dead. Do you by chance know the original web site? Thank you
    Don

    ReplyDelete
  2. Thanks, Don. I changed the opening of the article and added some links to Model Railroad Hobbyist articles that are close to what was available.

    ReplyDelete
  3. Sorry, I forgot to add that the original website is completely dead.

    ReplyDelete