Author Topic: Keep-alive install questions  (Read 1254 times)

ON28

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Keep-alive install questions
« on: December 12, 2021, 03:55:35 PM »
Hello group--

When wiring in my TCS KAs, can I just solder the blue lead to where the blue common from the LM joins the front headlight, since it's convenient? Or do I have to make a separate connection elsewhere on the blue common?

Also, is there a way to test my KAs for efficacy, since I bought them second-hand? Can they wear out?

Thanks!

William Brillinger

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Re: Keep-alive install questions
« Reply #1 on: December 13, 2021, 07:21:43 AM »
Here is a diagram for wiring a TCS KA with an LM-3
https://rpug.pdc.ca/index.php/topic,383.msg2867.html#msg2867

You can attached the Blue anywhere on the blue that is convenient.

Note for LM-2's the instructions are quite different.



- Bill Brillinger, RPUG Admin

Modeling the BNML in HO Scale, owner of Precision Design Co., and RailPro Dealer.


Alan

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Re: Keep-alive install questions
« Reply #2 on: December 14, 2021, 06:23:31 AM »
Hello group--

When wiring in my TCS KAs, can I just solder the blue lead to where the blue common from the LM joins the front headlight, since it's convenient? Or do I have to make a separate connection elsewhere on the blue common?

Also, is there a way to test my KAs for efficacy, since I bought them second-hand? Can they wear out?

Thanks!

KAs utilize electrolytic capacitors. Electrolytic capacitors don't wear out from use. They do however wear out from age. Counterintuitively, usage lengthens their life. A good quality electrolytic capacitor that is regularly used will work properly for a long time. An electrolytic capacitor that sits unused will be junk in an unusually short amount of time. As a conservative general rule electrolytic capacitors should see use at least once a year. The length of safe storage time is highly dependent upon capacitor quality. Poor quality units may begin to fail when stored for perhaps only a single year. High quality units will tolerate a few years of storage.

Assuming they are operated within their specifications, electrolytic capacitors fail due to loss of electrolyte or loss of oxidation or both. Loss of electrolyte results from poor construction materials or methods. It is the reason cheapie capacitors don't have a long service life and don't tolerate long storage time. The liquid part of the electrolyte evaporates out and the capacitor becomes useless. Operation at higher temperatures accelerates loss of electrolyte. Loss of oxidation results from disuse. All electrolytic capacitors slowly lose oxidation. Usage creates new oxidation to replace lost oxidation. Once oxidation falls to a certain point the capacitor no longer functions well enough to produce new oxidation. This is why even high quality units eventually go bad if stored unused.

When buying used KAs ideally you want units that have seen a lot of regular use meaning at no time have they sat unused for more than a year or two.

There are methods to determine how much capacity has been lost in a used capacitor. Let me know if you want to go down that path.
Alan

LK&O Railroad website

When I was a kid... no wait, I still do that. HO, 28x32, double deck, 1969, RailPro

ON28

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Re: Keep-alive install questions
« Reply #3 on: December 15, 2021, 03:58:00 PM »
Thanks for that.