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  • Topic: RRAmpmeter IV Question

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    • June 3, 2020 11:35 AM EDT
      • Kansas City, US-KS
         
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      RRAmpmeter IV Question

      Not sure if this is the correct location for this question.

      I plan to buy the RRAmpmeter.  I see they now offer a version 4.   It says it handles DCC of 18-20A.  Usually I see ranges of 1-20A or up to 20A.  I am running 10A Brutus.  Does anyone have the version 4?  Will it read down below 10A?  

    • June 4, 2020 8:19 AM EDT
      • Curmudgeon at Large, General Contractor???
         
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      My best recommendation is to check with Greg Elmassian here https://www.elmassian.com/

      ____________________________________

      We don't stop playing with trains because we grow old, we grow old because we stop playing with trains.....

       

    • June 4, 2020 8:06 PM EDT

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      Bob Cope said:

      My best recommendation is to check with Greg Elmassian here https://www.elmassian.com/

      Perhaps you should recommend searching LSC first ?

    • June 5, 2020 12:16 AM EDT
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      I have searched here.   

    • June 5, 2020 7:58 PM EDT

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      Rooster said:
      Bob Cope said:

      My best recommendation is to check with Greg Elmassian here https://www.elmassian.com/

      Perhaps you should recommend searching LSC first ?

      Then perhaps you should go with Bob Copes recommendation ?

       

    • June 5, 2020 7:59 PM EDT

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      Bob Cope said:

      My best recommendation is to check with Greg Elmassian here https://www.elmassian.com/

      bump

    • June 5, 2020 8:06 PM EDT

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      I pull 4 amps on my Crest Elite running what I run as the analog meter shows it.

      However it works

    • June 5, 2020 10:34 PM EDT
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      Well, I got an answer from Tony's Trains tech.  Said it does go down to 0.1A.  I figured but for $100 I wanted to be certain.  Didn't want to have to ship it back.  

    • June 6, 2020 10:54 PM EDT
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      Glad you got an answer for your question.

      ____________________________________

      We don't stop playing with trains because we grow old, we grow old because we stop playing with trains.....

       

    • June 14, 2020 9:05 AM EDT
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      Derailed said:

      Not sure if this is the correct location for this question.

      I plan to buy the RRAmpmeter.  I see they now offer a version 4.   It says it handles DCC of 18-20A.  Usually I see ranges of 1-20A or up to 20A.  I am running 10A Brutus.  Does anyone have the version 4?  Will it read down below 10A?  

      Hi Derailed - You received your answer.  I do have the RRamp V.4 and find it a great tool.  Let me know if you have any questions after you start using it.  Keep in mind that your DCC's track power voltage drops about 1.5 volts on the outputs in your DCC decoder.  This is a good data point to consider when you're adjusting your DCC decoder's outputs for things such as lighting, smokers, etc.  Also, when measuring voltage outputs on your decoders, do so under "load", i.e., have the device connected to the decoder's output, e.g., light, motor, smoker, etc.

       

      ____________________________________

      Tom White

      LGB Railfan - LocomotivesPro

      https://www.olddominionrailways.com/

       

    • June 15, 2020 12:58 PM EDT
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      Thank you.  I have to wait until next month as I bought a new Pustefix car for a price I couldn't pass up.  Need to replenish my Train Stipend.  ;)  

    • June 16, 2020 9:57 AM EDT
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      "Keep in mind that your DCC's track power voltage drops about 1.5 volts on the outputs in your DCC decoder."

      Is this due to a bridge rectifier inside the decoder?  1.5v is pretty close to the voltage drop across the 2x diodes in a BR.  I assume the decoder has some form of BR for accessories such as lights and smoke.  

      One of these days I will take an electronics class at the local college.  

    • June 16, 2020 10:16 AM EDT
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      Derailed - I'm not an electronics engineer so can't answer your question.  Someone like Greg Elmassian will need to chime in on that one.

      I install a lot of Massoth XLS DCC/DC Sound Decoders.  Massoth Technical Department informs me that the outputs on these decoders is not DC or DCC Voltage.  Instead it's pulse modulation with 25 volts (peak voltage) and smaller for lower voltage.  So, they advised me to use an RMS Multimeter in AC mode with load to measure the voltage outs from their decoders. So I don't use the RRamp to measure these decoder's outputs; I use the RRamp to measure the DCC voltage from my Command Stations to the track.....and amps.

      I'd be curious if Greg or others know whether this approach is used by other DCC Decoder manufacturers, such as ESU, Soundtraxx, etc.

      Tom

       

      This post was edited by Thomas White at June 16, 2020 10:17 AM EDT
      ____________________________________

      Tom White

      LGB Railfan - LocomotivesPro

      https://www.olddominionrailways.com/

       

    • June 16, 2020 10:34 AM EDT
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      Derailed said:

      "Keep in mind that your DCC's track power voltage drops about 1.5 volts on the outputs in your DCC decoder."

      Is this due to a bridge rectifier inside the decoder?  1.5v is pretty close to the voltage drop across the 2x diodes in a BR.  I assume the decoder has some form of BR for accessories such as lights and smoke.  

      One of these days I will take an electronics class at the local college.  

      Its not a bridge rectifier, at least not for the motor output, its an H bridge. For lights and such it would be a rectifier circuit of some kind. Also, on the switchable outputs (lights, smoke), there is also a switching transistor in the circuit. So yes, your actual voltage output would be reduced by the forward bias voltages of these components.

      This post was edited by David Maynard at June 16, 2020 10:35 AM EDT
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