Author Topic: Low voltage warning  (Read 167 times)

ON28

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Low voltage warning
« on: July 31, 2020, 07:25:48 PM »
Per an earlier question about a low voltage warning, I checked my NCE base station output and it was 14.25v, I don't want to increase it. On hard-wired layout segments the warning usually turns off soon enough, and all my LMs are up to date. I also have KAs in my locos, and I try to get a feeder to every rail except my Atlas metal frogs, which are unpowered. I guess I'll just live with it.

William Brillinger

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Re: Low voltage warning
« Reply #1 on: July 31, 2020, 08:07:20 PM »
If you have KA's on Bridge rectifiers, your LM is only seeing 13.25v as there is a voltage drop on the bridge rectifier.
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Modeling the BNML in HO Scale, owner of Precision Design Co., and RailPro Dealer.


ON28

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Re: Low voltage warning
« Reply #2 on: August 01, 2020, 12:01:52 AM »
If you have KA's on Bridge rectifiers, your LM is only seeing 13.25v as there is a voltage drop on the bridge rectifier.

The KAs are on LM3s, so no bridge rectifiers needed.

G8B4Life

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Re: Low voltage warning
« Reply #3 on: August 01, 2020, 01:44:29 AM »
I checked my NCE base station output and it was 14.25v

How did you measure this? If 14.25v is the actual true (rms) output then you shouldn't be getting any low voltage warning from that figure, unless you have places around the layout with seriously high voltage loss.

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ON28

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Re: Low voltage warning
« Reply #4 on: August 01, 2020, 10:55:12 AM »
I opened the base station and measured inside with a digital multimeter per this video.

William Brillinger

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Re: Low voltage warning
« Reply #5 on: August 01, 2020, 11:39:18 AM »
what does the LM report for track voltage? does it agree?
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G8B4Life

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Re: Low voltage warning
« Reply #6 on: August 01, 2020, 12:54:50 PM »
I opened the base station and measured inside with a digital multimeter per this video.

Well that's a different way of checking voltage levels. Of course if I own a PowerCab and not a Power Pro so I've never read the manual. So given that we can be pretty well sure that you are putting 14.25v to the track, then

what does the LM report for track voltage? does it agree?

^ This would also be my next question. I'd possibly be inclined to go around the layout with a bridge rectifier and DMM in hand and measure directly too if it happens in known spots. Apart from that the only thing I can think of is the operation of the KA's somehow cause it.

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William Brillinger

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Re: Low voltage warning
« Reply #7 on: August 01, 2020, 02:56:12 PM »
also, are you using a KA? or PBM? If a KA, what brand? (PBM is Ring's Keep Alive Product)
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ON28

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Re: Low voltage warning
« Reply #8 on: August 02, 2020, 04:23:53 PM »
Checking inside is per NCE's instructions for also increasing voltage. I am using TCs KA3s and 4s. Volatge per the HC is usually around 13.2, less often 13.4. I've been fastidious about feeders to every rail, and have also added brass bus bars between the stock and closure rails, as well as between the stock rails and points, on my Atlas Custom Line Code 100 switches. (Peco does the latter on their switches, if you look close.)