How to Measure Mains / Line Voltage and Harmonic Distortion using a USB Oscilloscope?

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  • Опубликовано: 17 ноя 2024

Комментарии • 39

  • @Kamel419
    @Kamel419 5 лет назад +4

    literally the only well done computer voice video i've seen

  • @kentvandervelden
    @kentvandervelden 7 лет назад +3

    Interesting video. I really enjoyed the explanation of the current return path via the probe's capacitance (13:00)

  • @zerodegrekelvin2
    @zerodegrekelvin2 5 лет назад +1

    Excellent demo to measure main power AC!! Two thumbs up video! I cannot believe there are 13 people who dislike?

  • @antoniofilipe70
    @antoniofilipe70 5 лет назад +1

    Hello Virtins Technology. I'm the Institute IPRAD director in Portugal (Geobiology Portuguese Institute) and i've interest to by a Siglent unite to mesure Dirty Eletricity. Can you make a vídeo showing a simple process of adjustement and mesurement? Thank you so much and congrats for your very good channel. Have a good week.

    • @VirtinsTech
      @VirtinsTech  5 лет назад +1

      A standalone digital oscilloscope is usually a 8-bit ADC device. It is not able to measure THD with a good accuracy (e.g. lower than 1%).

    • @antoniofilipe70
      @antoniofilipe70 5 лет назад

      @@VirtinsTech Thank you for your response.I've see this video with a similar equipament and I've hope that it was identic. ruclips.net/video/lUTRq--3AvU/видео.html

  • @eddyde115
    @eddyde115 4 года назад

    !!! Great video however there is one mistake I noticed, On your digram showing the power receptacle or outlet, you have the Line (L) and Neutral (N) reversed. At lest here in North America, with the Earth or Ground at the bottom, the Neutral is on the left (larger opening) and the Line (smaller opening) is on the right.

    • @VirtinsTech
      @VirtinsTech  4 года назад

      Many thanks for highlighting the difference in mains sockets between North America and Singapore / UK.

  • @dragilla
    @dragilla 2 года назад

    Can one use your USB oscilloscope as network analyzer, since it has a signal generator built in? I would like to calibrate my LISN.

    • @VirtinsTech
      @VirtinsTech  2 года назад +1

      The Multi-Instrument software license has a few levels. Please refer to the function allocation among different license levels at www.virtins.com/multi-instrument.shtml. Multi-Instrument Pro supports Bode Plot (called Transfer Function in the software) through two-channel FFT. The test signal generated by the signal generator should be fed into both the DUT and the input Ch. B, and the response from the DUT should be fed into the input Ch. A. This function can also be used as an impedance analyzer if a reference resistor is added. Please refer to Section 3.2.6 of the software manual.

    • @dragilla
      @dragilla 2 года назад

      @@VirtinsTech thank you. What I want to do is connect the network analyzer to my LISN, sweep the frequency range 9 kHz - 30 MHz, save the frequency response data and use this curve to apply corrections to measurements taken later using my LISN. Is this doable in the way that you described above? Do I need the pro license for that?

    • @VirtinsTech
      @VirtinsTech  2 года назад +1

      @@dragilla Magnitude frequency response can be measured with single-channel FFT. Once it is done, right click the spectrum analyzer window and select "Generate Frequency Compensation File (Flat)" to output a FCF file. The file can be loaded into the Spectrum Analyzer via [Spectrum Analyzer Processing]>"Intra-Frame Processing">"Compensation 1" or "Compensation 2". The subsequently measured magnitude frequency response will be compensated. The above measurement can be done with the Multi-Instrument standard license

    • @dragilla
      @dragilla 2 года назад

      @@VirtinsTech Fantastic! Thank you very much.

  • @smartups1
    @smartups1 Год назад

    Which model number of your oscilloscope you use .

    • @VirtinsTech
      @VirtinsTech  Год назад

      VT DSO-2810 was used in the video.

  • @dragilla
    @dragilla 2 года назад

    Hi, Can you show each harmonic and its level? I mean both visually and in numbers. Thanks

    • @dragilla
      @dragilla 2 года назад

      Also, could this oscilloscope/spectrum analyzer be used, to do pre-certification tests of conducted emissions (150kHz to 30MHz), assuming a LISN is used?

    • @VirtinsTech
      @VirtinsTech  2 года назад +1

      The spectrum analyzer window in the video shows the individual harmonic levels. These harmonics will become prominent if the vertical scale is changed from linear to logarithmic. The small windows called DDP (Derived Data Point) viewers can be used to display each individual harmonic level digitally by selecting the respective DDP, e.g. f1RMS_A(EU), f2RMS_A(EU), f3RMS_A(EU), etc. There is actually another window called DDP Array Viewer. It can be used to display a summary table of Harmonic Frequencies, RMS, Phases of up to 100 harmonics.

    • @VirtinsTech
      @VirtinsTech  2 года назад +1

      yes it can be used in conducted emission test

  • @jackietrove4637
    @jackietrove4637 4 года назад

    How does the software display "actual voltage" when you are using a x10 probe? I am new to scopes, but wouldn't 240 volts show as like 24 volts, how does the scope or software see it as the actual voltage when using the x10 probe?

    • @VirtinsTech
      @VirtinsTech  4 года назад

      There is a Probe Switch Position selection box in the second toolbar from the top. When a x10 probe is used, select "2", which tells the software to use the second probe attenuation factor configured at [Setting]>[Calibration]>"Probe Calibration Factor". Its default value is 10.

  • @miguelcalderon5841
    @miguelcalderon5841 4 года назад

    Thanks! I have a question.My computer is portable, no desktop. Are there differences for the measure? Thanks for all .

    • @VirtinsTech
      @VirtinsTech  4 года назад +3

      A portable computer is usually floating, so the floating ground differential method can be used, as illustrated by the experiment with a table PC in the video.

  • @eibmoz76
    @eibmoz76 7 лет назад

    Great video! In floating mode would it be enough to connect probe only to "Live" pin and not use channel B? Don't know if my Oscilloscope software supports Channel A-B in Spectrum analyzer mode.
    Have both Laptop (battery) and USB oscilloscope, with 100x probes.
    I wish to measure the 220v 50 hz AC mains for "Dirty Electricity" as in spikes in 1 Khz-120 Khz range (Spectrum analyzer mode). Thanks for any insight.

    • @eibmoz76
      @eibmoz76 7 лет назад

      Another question. If i wanted to remove/filter the mains 50 Hz frequency. How to do so? Notch filter, high pass filter, attenuator or something else?

    • @VirtinsTech
      @VirtinsTech  7 лет назад

      In floating mode, if you only connect one probe tip to "Live", then there will be no direct return path for the electric current except through the parasitic capacitor between the probe ground and the mains ground (see video: 12:50 ~ 13:40) which is not stable.

  • @arvydaszinkevicius830
    @arvydaszinkevicius830 9 лет назад

    Thanks a lot. Very informative video.

  •  5 лет назад

    My computer is running hot with emf's. I checked with the Stetzerizer meter and it shows 1500 on it. Would you know how to lower the computers radiation level?

    • @PhillipParr
      @PhillipParr 4 года назад

      Turn it off? Your computer is using EMF to function.

    •  4 года назад

      @crocket I know..tried and they came out with the cops to put smart meter back on! so pissed. Now 5G is coming...now what?

  • @alexandrunicuAnghel
    @alexandrunicuAnghel 8 лет назад

    Hi, thanks for great info. Are this type of measurements available for any type or grounded scope?

    • @VirtinsTech
      @VirtinsTech  8 лет назад

      THD measurement function is usually not available in an ordinary digital oscilloscope. Furthermore, an ordinary oscilloscope is usually only 8-bit. This will limit its ability to measure a devices with a low THD.

    • @alexandrunicuAnghel
      @alexandrunicuAnghel 8 лет назад

      I have : RIGOL DS1054Z, it has some math operations among which FFT,so I can take the values and calculate the THD. What do you think?
      thanks!

    • @VirtinsTech
      @VirtinsTech  8 лет назад

      Three points to note: (1) Resolution of the FFT: for THD measurement of a 50Hz/60Hz signal, you need a frequency resolution of, say less than 1Hz. (2) Spectral Leakage: Measuring using a cursor on the screen to get the RMS/Amplitude/Power/Energy of a particular frequency component is correct ONLY WHEN the signal is coherently sampled (Please refer to: Coherent Sampling on Wikipedia). This is usually not the case. A window function can reduce spectral leakage but it cannot eliminate it. You can check this by inputting a 2Vpp sinewave to the oscilloscope and see whether you can get 0.707 Vrms in the FFT graph by simply using the cursor to measure on the screen. On the other hand, software can have a good algorithm to get the correct value in FFT results even if spectral leakage is inevitable. (3) Bit depth. It would be difficult for a 8-bit digital oscilloscope to measure THD lower than 1%. So it really depends on what THD measurement accuracy you want.

  • @tjunkieu2b
    @tjunkieu2b 3 года назад

    the neutral and line are swapped in the pictures

    • @VirtinsTech
      @VirtinsTech  3 года назад

      Thanks, but this is a UK / Singapore power socket, which is different from a US one.

  • @srinivass2836
    @srinivass2836 6 лет назад

    Very nice sir

  • @princenephron7546
    @princenephron7546 5 лет назад +1

    If this oscilloscope doesn't have a completely isolated power supply and shares a common ground with the USB, then this thing is a piece of garbage. I mean, FFS, a simple magnetically coupled power supply and some isolater IO chips aren't that expensive, ya cheap-ass chinesium designers.

    • @VirtinsTech
      @VirtinsTech  5 лет назад +1

      Most oscilloscopes (being standalone or PC based) in the market do not have completely isolated power supply. The connection to protective earth (PE) is required for safety reason. If you really want to do floating measurement, power up your laptop with battery, or simply use an external USB isolator. Having a fixed built-in USB isolator is indeed a very BAD design, because it usually limits the USB communication speed to USB full speed (12M) and loses the flexibility to support both USB full speed and USB high speed (480M). A USB isolator that supports USB high speed is more expensive than the USB oscilloscope here.