Understanding RMS Values in AC Circuits √2 ? | Voltage | Current

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  • Опубліковано 24 гру 2024

КОМЕНТАРІ • 161

  • @dalesmith8666
    @dalesmith8666 11 місяців тому +70

    As an electrical engineer (myself retired), your explanation, with detail, is very well done ! Thumbs up. I've passed this along to others.

    • @fasillimerick7394
      @fasillimerick7394 4 місяці тому +1

      Hello there fellow EE! Some time ago in a music store I was with a friend and his girlfriend. She asked what RMS meant, and how it related to guitar amplifiers. I paused, and started running through my head how to explain it properly to a layman. She said "it's okay if you don't know". I really wish I had this video to help explain it at the time.

  • @billcrowell5096
    @billcrowell5096 11 місяців тому +49

    This is the single best presentation on Ohm's Law, DC and AC circuits that I've EVER seen! I've been doing electronics since 1972.

  • @martinfarfsing5995
    @martinfarfsing5995 10 місяців тому +9

    I have college and university degrees in electronics and electrical engineering, oh how I wish your tutorial and internet site existed then , I'm looking thru your sites , thank you

  • @envitech02
    @envitech02 11 місяців тому +25

    In 1988, right out of high school, I studied electronics engineering. I studied Ohm's Law, P=VI and RMS. But I never got around to why RMS is RMS. Now as a 50+ old geezer, I know. The animation at 4:05 is brilliant!!!

    • @monteceitomoocher
      @monteceitomoocher 11 місяців тому +1

      Something a visual representation makes a concept much more clear and understandable.

  • @d3vilman69
    @d3vilman69 11 місяців тому +8

    Damn. That is one crystal-clear explanation of the RMS value. I know there is such a thing as RMS voltage in AC circuits but never could comprehend how it is derived. Hope I had UA-cam in my college days..

  • @davidjones6288
    @davidjones6288 3 місяці тому +1

    This is the most beautiful delivery I've ever experienced, the clarity of speech, the pauses to let it all sink in. This is a treasure. Thank you Sir. An enormous amount of effort has been put into this, resulting in the bringing about of perfection. A truly brilliant job.

  • @tharangakpkk
    @tharangakpkk 10 місяців тому +1

    Best video as an electrical engineer i have ever seen explaining this...

  • @loren6609
    @loren6609 6 місяців тому +2

    this is pure gold. one of the best videos ive seen. thank you very much

    • @Profmad
      @Profmad  6 місяців тому

      Wow, thank you!

  • @note9redmi17
    @note9redmi17 11 місяців тому +4

    Good job. You managed to explain a not simple concept using concise and effective approach.

  • @Electric_Sherlock
    @Electric_Sherlock 8 місяців тому

    This is not how I learned it but exactly how I understood it to be. Far too often do we expect others to teach us and make us understand. Yes, there are some teachers that are better than others, but that doesn’t diminish the responsibility we have to ourselves for our own understanding of a topic

  • @gunaratna123
    @gunaratna123 11 місяців тому +2

    I had a blurred idea about RMS. It started with measuring UPS and SMP power supplies. Understood that cheap multimeters cannot measure the correct voltage etc. You cleared it. Thank you!

  • @eltranjbar6837
    @eltranjbar6837 7 місяців тому +1

    Great explanation after years of being an engineer we are getting to understand voltage and current 😂😊
    I always thank God that there are scientists who think and research to help us understand such things .

  • @Tim-Kaa
    @Tim-Kaa 11 місяців тому +5

    Beautifully explained, thank you!

  • @gregkocher5352
    @gregkocher5352 11 місяців тому +1

    It was decades ago, we went through the full derivation for RMS. About 15 years into my career I forgot how to derive it, but knew the sqrt of 2. Lol. This is a very nice review of the subject.

  • @florentinosanchez3969
    @florentinosanchez3969 Місяць тому

    Best explanations in the whole internet. Ive been days looking for explanations and there wasnt any video which make me understand. But this one is awesome. Thank you so much

  • @jensschroder8214
    @jensschroder8214 11 місяців тому +5

    The voltage changes in the US 60 times, in Europe 50 times.
    In Japan there are both networks, one 50Hz and one 60Hz, but only 100V RMS
    The voltage is 220V RMS in Russia, 230V RMS in continental Europe and 240V RMS in England.
    V peak is almost never used and V RMS is almost always used!
    V peak is only used when the AC voltage is rectified and the expected maximum DC voltage is asked.
    V RMS x SQR(2) = V peak
    V RMS x1,414 = V peak

  • @mp4338
    @mp4338 11 місяців тому +5

    The peak voltage is usually used for capacitor. You must select capacitor voltage w/this voltage and no Vrms. In DC capacity the selected voltage must be function of the capacitor model. It is better 2 time more voltage than used dc voltage (specialy for tantalum).

  • @Rosemarykimathi
    @Rosemarykimathi 25 днів тому

    Simply amazing! Big Thank you!
    I was almost giving up on my EE1 and EE2 lectures. everything makes sense now!

  • @mohsenyousef4505
    @mohsenyousef4505 8 місяців тому +1

    If I’d have known this analogy during my study it would’ve saved lots of time and could pass the class with better grade

  • @adhamraad8619
    @adhamraad8619 11 місяців тому +4

    Unbelievable
    Very interesting 👍
    Thanks

  • @uksachin8892
    @uksachin8892 10 місяців тому +4

    Suprised To see a new way to derive The equation. initially I know a method to derive this equation using calculus but this method is more mind wobbling...

    • @am9ac11
      @am9ac11 10 місяців тому +2

      As an electrical engineer myself, this method explains how ac power formulas started, but the calculus wad explains the understanding of what the words Root Mean Square mean. You can't average and sine wave centered on zero, so square it, now its all positive, now average it (mean), now reverse the squaring(root). And voila RMS and you get the same answer Vpeak / root 2.

  • @naharsingh7537
    @naharsingh7537 10 місяців тому +1

    Very nice topic for basic Electrical engineering

  • @moazzamjadoon4436
    @moazzamjadoon4436 11 місяців тому +1

    I have known about the RMS formula for at least 30 years. It's the first time that I know from where this equation comes.

  • @henryaganon514
    @henryaganon514 8 місяців тому

    as a retired ECE this should be the way we teach this to kids.

  • @BeautifulPlaces7290
    @BeautifulPlaces7290 9 місяців тому

    The best video with the best and simplest explanation I have ever seen

  • @Jo20020
    @Jo20020 6 місяців тому +1

    it was amazing.
    Thank you

  • @vincentpinto1127
    @vincentpinto1127 9 місяців тому

    Fascinating! Wish I had learnt it like this in the early 80s!

  • @donepearce
    @donepearce 11 місяців тому +1

    Thank you for using the term Average Power. So many people who should know better think that the product of RMS voltage and RMS current is RMS power. That irritates.

  • @mohamedkhalid7708
    @mohamedkhalid7708 16 днів тому

    Excellent explanation. Thanks

  • @esmeraldacastaneda5939
    @esmeraldacastaneda5939 17 днів тому

    Great explanation, thank you!

  • @mach1553
    @mach1553 11 місяців тому +1

    RMS is the "square Root of the sum (Mean) of the Squares / 2" - By taking measurements of a sinewave evenly along both sides & peak, squaring each, add them together, then square root the sum which is the RMS voltage. The equation V=V/√2 is the simple method.

    • @civildiscourse2000
      @civildiscourse2000 10 місяців тому

      And that's why we use it - it's simple. It's only necessary to use a more sophisticated approach for non-sinusoidal waveforms, would you agree?

  • @hugovanderzee4944
    @hugovanderzee4944 8 місяців тому

    This is by far the most clear explanation I have seen. Well done!
    Minor detail, at 8:55 it says that Vpeak is 325.3. I suppose this needs to be 352.3 (as it states a few seconds later correctly).

  • @malikaamir6412
    @malikaamir6412 9 місяців тому

    Best video on this topic uptill now 👍👍👍

  • @eduaid777
    @eduaid777 4 місяці тому

    Thanks machn.. happy to see sri lankan channel in this topic

  • @B00BS.
    @B00BS. 10 місяців тому

    Brilliant explanation using the animation. Liked it!

  • @smesui1799
    @smesui1799 6 місяців тому +1

    Superb, and clear. Seems perhaps AI ( Artificial Intelligence ) may have assisted in the production of this video, as evidenced by the voice of the presenter.

  • @Scorpster
    @Scorpster 11 місяців тому +6

    OMG, I've known about RMS for 45 years, but always thought household power was peak to peak. Even wired my own house from pole to multiple subpanels, how could I have missed that? Just one of the many new things I learned today....

    • @wilcoxdaniel9825
      @wilcoxdaniel9825 10 місяців тому +1

      A negative voltage multiplied by a negative current gives always a positive power. Power then cannot be negative.

  • @VivekMudgil-rf2co
    @VivekMudgil-rf2co 10 місяців тому +1

    Excellent Professor

  • @trangia12
    @trangia12 10 місяців тому

    Great presentation, thank you.

  • @mourchidMohammad
    @mourchidMohammad 7 місяців тому

    Best job think you for this

  • @danburch9989
    @danburch9989 11 місяців тому +8

    The RMS value is .707 x peak value of a pure sine wave

    • @civildiscourse2000
      @civildiscourse2000 10 місяців тому

      Yes, 0.707 being an approximation of 1/(square root of 2).

  • @piotrgorynski1810
    @piotrgorynski1810 11 місяців тому +2

    Why youtube and guys like you didn’t exist in 1992? DZIĘKUJĘ 🎉❤😊

  • @johndevires5911
    @johndevires5911 11 місяців тому +1

    NOW I understand. Thank you very much. 👍

  • @Esraa_MA
    @Esraa_MA 9 місяців тому

    Wow! 🤩 you smashed it👏🏻👏🏻👏🏻👏🏻

  • @B00BS.
    @B00BS. 10 місяців тому +1

    So, if my RMS is 120V and the peak is 169.7V (as in 8:40) and I use a rectifier to convert it to DC, will I get somewhat 169.7V reading in a voltmeter at the end???

  • @bretmutasa2676
    @bretmutasa2676 7 місяців тому

    Very good, I wish you could cover more topics

  • @GTLearningSolutions
    @GTLearningSolutions 6 місяців тому

    Superb Explanation

    • @Profmad
      @Profmad  6 місяців тому +1

      Thank you 🙂

  • @nkvirk988
    @nkvirk988 10 місяців тому

    Excellent explanation

  • @straightstreet7143
    @straightstreet7143 11 місяців тому +1

    Very clear man 👍

  • @ferhatnusreturuc1809
    @ferhatnusreturuc1809 11 місяців тому +1

    thank you, very good explaination.

  • @dajo4349
    @dajo4349 7 місяців тому

    Very good videos. I liked the voice, too. I liked the water analogies. I’m going to look at your other videos. Thanks

    • @Profmad
      @Profmad  7 місяців тому

      Awesome, thank you!

  • @blaisekataliko7030
    @blaisekataliko7030 2 місяці тому

    thank you so much for your explanation, is wonderfull

  • @ErwinAarnoudse
    @ErwinAarnoudse 4 місяці тому

    Very well explained. Thank you very much for sharing this video 👍

  • @mathiazhagan92
    @mathiazhagan92 8 місяців тому

    Super explaining. ..

  • @mikeb4650
    @mikeb4650 10 місяців тому

    Phenomenal introduction. Future videos on phase discrimination and power factors would be extremely beneficial. For myself I have never been successful with teaching 746 watts = 1HP, but a 110v rms, 1 hp motor takes 10.2amps average.

    • @garbo8962
      @garbo8962 5 місяців тому

      Learned many years ago there are 4 looses in motors: stator, rotor, core & windage & friction. So the average AC t2 & 4 pole motors usually a 1 HP.Motor pulls 1,000 watts. Never trust HP rating on lying cheating communist china saws, drill presses etc. Way over rated.

  • @GamingMachine-r4c
    @GamingMachine-r4c 11 місяців тому +1

    Thank you I use in study in 12th-Sci

  • @sagittariusa5642
    @sagittariusa5642 11 місяців тому +4

    Next video ÷ how to transformer less(Capacitor) power supplies work. It Actually convert the voltage? And how about efficiency.

  • @tmatheson54
    @tmatheson54 10 місяців тому

    Nice. Thanks. Having exposure to this many times during my 40 plus year career in engineering and as a hobby as a young teenager I found that for RMS when I really got to the Root of this I found that Squares can be really Mean!
    😮. Sorry. Humor. I really did like the presentation.

  • @simontsegaygebre4196
    @simontsegaygebre4196 11 місяців тому +1

    Wonderful presentation and animation! Keep it up
    However, here
    II do not see any mean square .
    Do it with the mean square. Using statistics formula.

  • @Yorumcu63
    @Yorumcu63 22 дні тому

    Great video

  • @amifamousyet1146
    @amifamousyet1146 10 місяців тому +1

    This is gold

  • @sinaabdi2815
    @sinaabdi2815 9 місяців тому

    Thank you very much. Im electric engineer but never understand these . Thank you

  • @7trepwebstarfieldpaliar943
    @7trepwebstarfieldpaliar943 7 місяців тому

    If you were my electrical engineering professor, I surely will have the best grades❤

  • @heronimousbrapson863
    @heronimousbrapson863 11 місяців тому +2

    The current changes direction 100 times a second (120 times in North America). It goes through 50 (60) complete cycles per second.

  • @JoeMcLutz
    @JoeMcLutz 11 місяців тому +1

    Thank You. 👍🏻

  • @eltek04
    @eltek04 11 місяців тому +1

    Very useful

  • @msg1956
    @msg1956 8 місяців тому

    Excellent..!

  • @mixme8655
    @mixme8655 10 місяців тому

    New subscriber always watching your videos very interesting❤

  • @TallLongGuy
    @TallLongGuy 11 місяців тому +1

    What service does the voice over. Everyone is using it.

    • @civildiscourse2000
      @civildiscourse2000 10 місяців тому

      I'd love to know as well. Unfortunately it's used for a lot of garbage, and this video is very much the opposite.

  • @cosmicazur
    @cosmicazur 11 місяців тому +1

    Awesome

  • @yasiral-shawi7521
    @yasiral-shawi7521 7 місяців тому

    Good job

  • @aniiiiiiiiiiiiii
    @aniiiiiiiiiiiiii Місяць тому

    What my professors with a phd could not explain was done here so brilliantly🫶🏻but here's another question, which parameter do the conventional Multimeters measure? If it's RMS (which really is), why? And if not, why?

  • @ricardo6988
    @ricardo6988 6 місяців тому

    man thank you so much

  • @kamalhamdi6739
    @kamalhamdi6739 11 місяців тому

    Thank you for information khalid du Maroc Casablanca

  • @Shivani12326
    @Shivani12326 11 місяців тому

    Nice Explanation I have a one question that why power is only in positive

    • @rickb7933
      @rickb7933 11 місяців тому

      Power can also be zero but not negative. Think about it intuitively. How could there be negative power? Either work is being performed (positive) or it isn't (zero). The voltage and current being either positive or negative simply refers to the direction the current is flowing. Regardless of direction work is still being performed.

  • @normstaley9799
    @normstaley9799 11 місяців тому +1

    simply put - to find Vrms multiply peak voltage by the sin of 45 degrees, and divide Vrms by sin 45 to get peak Voltage

    • @thomasmaughan4798
      @thomasmaughan4798 11 місяців тому +1

      It works but has nothing to do with sine per se; just that the sine of 45 degrees (in a 360 degree circle) just happens to be the square root of 2.

    • @normstaley9799
      @normstaley9799 11 місяців тому

      @@thomasmaughan4798 I didn't mean to imply that it did, just an easy way to remember the numbers

    • @normstaley9799
      @normstaley9799 11 місяців тому

      @@thomasmaughan4798 also the presence or absence of a "360 degree circle" has no bearing on the sin of any angle

    • @thomasmaughan4798
      @thomasmaughan4798 11 місяців тому

      @@normstaley9799 "just an easy way to remember the numbers"
      That's good; whatever works! I have known this relation for decades but this video simplifies it considerably and removes trigonometric functions.

    • @normstaley9799
      @normstaley9799 11 місяців тому

      @@thomasmaughan4798 If you think all the algebraic steps this video goes through to get the answer is simpler than using the method I suggested then we should have a discussion on the meaning of the word SIMPLE

  • @abdelmalek9682
    @abdelmalek9682 11 місяців тому

    Is this concept of average AC power applies to both 1 and 3 phases systèmes ?

  • @SachinPatel-pe6rv
    @SachinPatel-pe6rv 11 місяців тому

    Great video. love the tiktok voice

  • @pibbles-a-plenty1105
    @pibbles-a-plenty1105 11 місяців тому

    Yeah, so far, so good. But how does one come up with RMS voltage and current?

  • @OlaJendor
    @OlaJendor 11 місяців тому

    This is so interesting

  • @dashsidhartha
    @dashsidhartha 10 місяців тому

    In other words, RMS value is the DC equivalent voltage in order for the circuit to consume the same power if connected to a DC source. Am I correct?

  • @milroykoelmeyer
    @milroykoelmeyer 11 місяців тому

    Sir
    l want to know what is differnes between
    RMS & PMPO and when the output power is given in PMPO IN amps how to calculet the RMS POWER OUT PUT OF THEAMP
    AWATING for teply pl pl

  • @mohsenyousef4505
    @mohsenyousef4505 8 місяців тому

    So, the difference between either the V or I RMS and the effective peak voltage or current is basically the loss it happens during the power transmission!

  • @dalenassar9152
    @dalenassar9152 7 місяців тому

    Doesn't Root-Mean-Square (RMS) imply SQUARING a time-varying waveform, then taking the AVERAGE (MEAN) value of that, and finally taking the SQUARE root of all that?
    My guess is that dividing the peak by sqrt(2) only gives the RMS value of a SINE wave, but other waveforms need the whole RMS sequence. Isn't this what "TRUE RMS" DMM's do for 'any' waveform?
    THANKS MUCH!!!!
    --dalE

  • @sollykhan2385
    @sollykhan2385 7 місяців тому +1

    what can i say, apart from 'Shocking' 🙂

  • @merunaki2883
    @merunaki2883 2 місяці тому

    THE GOAAAATTTT

  • @cacornett58
    @cacornett58 9 місяців тому

    I think that the Average value is actually .637 of the peak. Avg= P * .637. So 169v*.637= 108.12vac.

  • @winniethepooh1931
    @winniethepooh1931 10 місяців тому

    My multimeter measured household peek to be 120v. Are multimeters RMS?

    • @KevinRudd-w8s
      @KevinRudd-w8s 10 місяців тому

      Most of the cheaper multimeters give an approximate RMS value which is usually not that far off anyway. Multimeters are available that give a true rns value. It will probably tell you in the specs for your meter which one you have.

  • @Mesa_Mike
    @Mesa_Mike 11 місяців тому

    We use 60 Hz in the USA and the direction of the current changes 120 times a second.

  • @CommercialGasEngineerVideos
    @CommercialGasEngineerVideos 11 місяців тому

    Thanks, never heard of this.

  • @markmanning2921
    @markmanning2921 11 місяців тому +1

    Isnt England 240v ?

    • @okaro6595
      @okaro6595 11 місяців тому

      Britain has officially 230 but in practice 240 V they play tricks with the marginals. In 1980 the IEC decided to harmonize 220 V and 240 V to 230 V European countries switched to 230 V but Britain just said they did and used the marginal to cheat.

  • @mirskym
    @mirskym 11 місяців тому

    Next - power calculation in three phase circuits

  • @farhadghasemi3684
    @farhadghasemi3684 11 місяців тому

    thanks

  • @mikeadler434
    @mikeadler434 11 місяців тому

    👍👍

  • @thorhammer6040
    @thorhammer6040 11 місяців тому

    you said 325v on the last slide but the graph says 352.3v. Typo

  • @RV35648
    @RV35648 10 місяців тому

    Power will not be +ve , it also varies from +ve to - ve like voltage and current , but understand a -ve or +ve will not matter in an appliance all it is only dissipation .

  • @joaochicora5080
    @joaochicora5080 3 місяці тому

    Muito bom

  • @jozsiolah1435
    @jozsiolah1435 11 місяців тому

    RMS Titanic didn't have the electric lines on when the crew members escaped before sinking. About 10 󾓥 󾓦 󾓧 󾓨 󾓩 󾓪 󾓫 󾓬 󾓭 󾓮s escaped from the back part using a rope to a smaller ultra modern motor boat, designed today.

  • @Menshinin
    @Menshinin 10 місяців тому

    Странно. Если сравнивать площадь полуволны и прямоугольника такой же ширины, там не корень из 2, а Пи делить на два.

  • @UnitFerminBDauag
    @UnitFerminBDauag 10 місяців тому +1

    ⭐⭐⭐⭐