Very interesting and very useful video for people who want to measure real power. Thank you
@Jnglfvr
Жыл бұрын
In the case of a sine wave with DC offset there is a workaround for a meter that is "true RMS" but not "true AC/DC RMS" such as the Uni-T in your demonstration. For sine waves only, the RMS value is the square root of the sum of the squares of the "symmetrical" sine wave and the DC offset. I.e., Vrms (DC offset) = sqrt(Vrms (no offset)^2 + DC offset ^2). Take for example a 4 V peak to peak sine wave with 1 V DC offset. The RMS value of this would be sqrt( (2/sqrt(2))^2 + 1^2)) = 1.73. If you use the Uni-T to measure this signal in AC mode you will get the non DC offset of 1.41. If you then switch it to DC mode it will correctly identify the DC offset as 1 V. SO with a little manual calculation taking the square root of the sum of the squares of both the AC and DC measurement you will get the true RMS value of the signal.
@KainkaLabs
Жыл бұрын
Yes, that´s right. But first you have to know this workaround, then you have to remember it and finally you have to get out a pocket calculator :-)
@Jnglfvr
Жыл бұрын
@@KainkaLabs Yes, of course. My only point is that it is possible to calculate the correct RMS of a DC offset sinusoid with a meter that is not True AC/DC. Of course this will only work for a sinusoid.
@rob80ra
3 жыл бұрын
Thid really cleared some matters! Thanks a lot!
@trumanhw
3 жыл бұрын
I got lucky and guessed it was gonna be counterintuitive -- and actually assumed it'd be the sqrt of 2 ... :) What I DON'T know ... is when, why and how RMS is more useful except as a relative (comparative) value when you have "known good" hardware you're comparing against -- or, if a mfr gives their info in RMS -- requiring people purchase more expensive test equipment to audit the product.
@tanech5542
5 ай бұрын
❤❤❤thank u very much
@howardostfeld3802
5 ай бұрын
I think you meant AD8436 not AD8736.😁
@faustsmith
6 жыл бұрын
Would you be doing a review of the "Victor 189" ac+dc multimeter?
@KainkaLabs
6 жыл бұрын
if you send me one :-)
@faustsmith
6 жыл бұрын
I haven't one. Maybe, the manufacturer Victor or a vendor may see this notice or request to provide for the purpose of review the Victor 189 logging multimeter .
@KainkaLabs
6 жыл бұрын
My channel isn´t big enough for a manufacturer to notice me :-)
@faustsmith
6 жыл бұрын
You are getting there. Try contacting them, the manufacturer, can't hurt, they might be happy to send you a unit for review.
@engr.salaheldin
2 жыл бұрын
Is this multimeter fluke 87v mesure (AC+DC)
@KainkaLabs
2 жыл бұрын
Which multimeter do you mean?
@engr.salaheldin
2 жыл бұрын
@@KainkaLabs Fluke 87V
@dimago11
6 жыл бұрын
great calculation abilities you got there... but where i live the square root of two squared equals TWO.
@KainkaLabs
6 жыл бұрын
Could you please point out at which time in the video this is, so that I can take a look at it.
@dimago11
6 жыл бұрын
at 9:45 you have made it very confusing with the squares going absolutely everywhere.
@KainkaLabs
6 жыл бұрын
What I wrote down is correct. I use the standard notation of mathematics as it is teached where I live. The "2" below the root is not in brackets together with the V. Thereby the SQRT(2*V*V) = SQRT(2) * V
@dimago11
6 жыл бұрын
well its not wrong, just confusing as F... Im used to excluding the V from the calculation as its not a quantity. Vrms = sqrt(0/2+4/2) = sqrt2 (V)
@OZ1LQO
4 жыл бұрын
Great series on a subject which many people find complicated. Very good points along the line, and even though I'm a professional myself, I still went straight to my bench to test and compare my three multimeters against the DSO :-) Thanks, I enjoy well-made videos on basics :-)
@trumanhw
3 жыл бұрын
YOU ARE A GOOD TEACHER!! There are MANY youtubers TRYING to explain things ... BUT, they suck at remembering what it was like to not know things. Apparently -- people with Asperger's are more extreme versions of this phenomena, in which they lack a sufficient practical application of theory of mind ... to where they can imagine what it's like to not know something ... You provided all of the information to appreciate your objectives ... and weren't just speaking out loud, audiblizing corresponding reactions to your own thoughts without explicitly helping us understand your thoughts... as (unfortunately) many (most) channels have done. Keep up the great work: Subscribed!
@mikeadler434
Жыл бұрын
👍
@soffronitsky
3 жыл бұрын
Please Roger, could you please explain me what you mean from 7:36 to 7:51? Thank you very much. Very clear and informative video!
@tech29X
5 жыл бұрын
Loved the explanation, thank you Raj.
@Ian.Gostling
3 жыл бұрын
I finally understand RMS, You are the First utube video I've seen that properly explains the origin based on ohms law better,thanks!
@JackZimmermann
7 жыл бұрын
Great explanation! Thanks!
@surgingcircuits6955
7 жыл бұрын
Excellent. Thank you.
@robertingersoll5289
5 жыл бұрын
First, for those criticizing - the German convention for voltage is U. Almost all great physicists who formed the basis of modern electronics used U. (That is why Travel is recommended for students.) ROGER - you have a gift for teaching Electronics concepts. Quit this racket of selling gizmos and teach electronics at your local university.
@davidprice2861
6 жыл бұрын
Please you can't go around pronouncing V as a U.. Or writing it thus.. I understand your English is a second language.. Appreciate your effort though..
@KainkaLabs
6 жыл бұрын
In ost of my videos I mention that in Germany (and most of Europe) the symbol for a voltage is not "V" but "U" to distinguish it from the unit Volts [V]. But of course I sometimes mix it up by myself between what I write down and what I say :-) Pardon me for that.
@keeleyhoek
4 жыл бұрын
@@KainkaLabs What do they use in Germany for potential energy? (I'm used to U meaning potential energy.)
@KainkaLabs
4 жыл бұрын
@@keeleyhoek Potential get´s the greek letter Phi (upper case). "U" is used in German for the potential difference (_not_ the potential _energy_). In electric fields potential difference and voltage are identical. That´s why "U" is correct for voltage. _Energy_ is always used with an "E" for energy or "W" for work. de.wikipedia.org/wiki/Potential_(Physik)#Das_Potential_am_Beispiel_des_elektrischen_und_des_Gravitationsfeldes
@musarichesmabuyangwa3706
7 жыл бұрын
very nice video...can you please help? i have just bought a trms digital multimeter..can you please help step by step on how do i connect my sginal gen and oscilloscope with the multimeters?
Пікірлер: 35