 Joined: 01/12/2018(UTC) Posts: 54 Location: Louisville, Kentucky
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I couldn’t find anything on the forum for this but something has me puzzled. And it might be just a lack of understanding on my part. But I got the CS3 and the Power Pack that goes with it. The power pack is set to 19v through the switch on the device. My CS3 is reporting 19.1v under the system settings. So far, so good. Then I decided to use my multi meter to see what voltage is provided to the track. My multi meter is a true RMS device so it should be fairly accurate. But it shows a reading of 10.74v constant. While all is working fine, it seemed low to me. Therefore I decided to measure the voltage output on the MS2 track box. That showed a reading of 13.2v while the MS2 says 18.6v. Where are those differences coming from? Does someone has an explanation for the behavior I am seeing? Not an electrician at all so hope for some insight from one of you. But I expected the voltage readings on the MS2 and CS3 to reflect the track voltage. Am I missing something?
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 Joined: 17/09/2006(UTC) Posts: 18,771 Location: New Zealand
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Have you got your multimeter on the AC or DC setting? It needs to be set to AC volts to get a proper reading. Those are the sorts of readings you will get with a DC setting.
The waveform put on to the track is neither AC or DC, rather it is more a squarewave signal. The AC setting on the multimeter is the closest thing that will read it properly.
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Joined: 01/12/2018(UTC) Posts: 54 Location: Louisville, Kentucky
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Originally Posted by: Bigdaddynz  Have you got your multimeter on the AC or DC setting? It needs to be set to AC volts to get a proper reading. Those are the sorts of readings you will get with a DC setting. Just checked that and that isn’t it either. When setting to DC, I get 12.2v when testing one way, and a negative value -12.2v when swapping the leads, exactly what I expected. At least for the + and - values. Not sure why it’s showing 12.2v in both cases.
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Joined: 08/11/2001(UTC)
Posts: 47
Location: Oppegård,
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Hi Marcel (?)
Is your multimeter capable of measuring 20+ kHz frequencies or is it merely for 50/60 Hz sinusodial waveforms ?
Regards
Tor Harald Bøhler
Oppegård, Norway |
Tor Harald Bøhler
Oppegård, Norway |
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 Joined: 04/08/2018(UTC) Posts: 1,156
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Originally Posted by: MarcelV Originally Posted by: Bigdaddynz Have you got your multimeter on the AC or DC setting? It needs to be set to AC volts to get a proper reading. Those are the sorts of readings you will get with a DC setting. Just checked that and that isn’t it either. When setting to DC, I get 12.2v when testing one way, and a negative value -12.2v when swapping the leads, exactly what I expected. At least for the + and - values. Not sure why it’s showing 12.2v in both cases. Hi Unless you have an AC+DC RMS mode, you probably need to combine the RMS AC and DC readings to get a more sensible result. the formula and more information can be found here: https://www.fluke.com/en-us/learn/blog/digital-multimeters/facts-about-true-rms-measurementhttps://www.fluke.com/en/learn/blog/electrical/what-is-true-rms
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 2 users liked this useful post by bph
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Joined: 17/09/2006(UTC) Posts: 18,771 Location: New Zealand
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Didn't I say to use the AC setting? Using the DC setting is wrong and a waste of time.
As I said the waveform approximates AC, you need to use the AC setting to properly read it.
Am I not being clear enough?
Having said that, my Fluke multimeter reads 12.3v output from my CS3 on the DC setting, and 14.8v AC on the AC setting even though the CS3 says track voltage is 19.1v and the power supply is set to the 19v option. Not sure why it is so low, my CS2 reads 18+v AC.
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Joined: 17/09/2006(UTC) Posts: 18,771 Location: New Zealand
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Thanks BPH, I learnt something today.
My Fluke 287 does have the AC+DC mode setting (as well as AC over DC or DC over AC).
I measured my CS3 track output voltage in the AC+DC mode and the reading was bang on 19.0v.
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2 users liked this useful post by Bigdaddynz
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Joined: 04/08/2018(UTC) Posts: 1,156
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Originally Posted by: Bigdaddynz Thanks BPH, I learnt something today.
My Fluke 287 does have the AC+DC mode setting (as well as AC over DC or DC over AC).
I measured my CS3 track output voltage in the AC+DC mode and the reading was bang on 19.0v. The Flukes are indeed very good, and generally way above my need. But I got my 289 at a very good discount price and thinking that it probably can measure it if I should need it in the future. and I haven't regretted it, as it turned out to be a lot more useful than imagined. Does your Fluke have the AC Low Pass Filter mode ? (blocks voltages above 1 kHz) In that mode, my fluke 289 reads approx 8,5 VAC, from the CS3+(no trains running). This is just for information, and other readings are similar to your 287 readings.
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Joined: 01/12/2018(UTC) Posts: 54 Location: Louisville, Kentucky
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Originally Posted by: Bigdaddynz Didn't I say to use the AC setting? Using the DC setting is wrong and a waste of time.
As I said the waveform approximates AC, you need to use the AC setting to properly read it.
Am I not being clear enough?
Having said that, my Fluke multimeter reads 12.3v output from my CS3 on the DC setting, and 14.8v AC on the AC setting even though the CS3 says track voltage is 19.1v and the power supply is set to the 19v option. Not sure why it is so low, my CS2 reads 18+v AC. I think you misunderstood. You was very clear. I did test in AC. Only after your response, I also tested DC to make sure I got different results (which was expected). I was just double checking myself.
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2 users liked this useful post by MarcelV
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Joined: 01/12/2018(UTC) Posts: 54 Location: Louisville, Kentucky
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Originally Posted by: bph No such mode unfortunately. Thanks for the info. Link was very informative. Now, is it worth for me to buy a new one that can do that? Probably not, I barely use this one and it works for all other things I use it for,
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1 user liked this useful post by MarcelV
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Joined: 10/02/2021(UTC) Posts: 3,886 Location: Michigan, Troy
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If your CS3 is set at the factory 16 volt track setting then it's fine.
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1 user liked this useful post by marklinist5999
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Joined: 17/09/2006(UTC) Posts: 18,771 Location: New Zealand
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Originally Posted by: bph Does your Fluke have the AC Low Pass Filter mode ? (blocks voltages above 1 kHz) As far as I know, the only differences between the Fluke 287 and 289 is that the 289 has a Low Impedance (LoZ) measurement mode and a Low Pass filter which the 287 does not have. If we use the math in the Fluke document using the measurements I took 12.3sq + 14.8sq = 151.29 + 219.04 = 370.33 sq root 370.33 = 19.24 volts So MarcelV, you could use this method with the multimeter you have to measure your CS3 track voltage.
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1 user liked this useful post by Bigdaddynz
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