ac: Mutual Inductance Example #2

[@sanwellbeatz1630]

Searched all over the internet for this and finally found it

[@240mains]

Hi again . this is the most info i can get out of book "Engineering Circuit Analysis" , year 1993 from publisher McGraw-Hill . Writing All Self terms is the same as with DC equation writing with NON coupled coils . Now , assuming 2 coupled coils , I2 flowing thru L2 gives an induced term of jwMI2 onto mesh I1 ( easy to realize ) . Next , using the Dot Convention with I2 Arrow and the Dot of L2 , we easily know the induced +-polarity onto L1 . Now we need to determine the correct +-sign of , jwMI2 . To find this +-sign , we use the same KVL traverse direction that was used when writing the Self term of L1 . Example : if we had Traversed L1 Clock-Wise and if we used the +-sign of L1 as we Entered L1 , then that is the same location we must use to pick the +-sign for the Induced term . Effectively , L1 will have 2 pair of +-polarities . +-pair One was used to write the Self term of L1 . the other +-polarity across L1 came from the Dot of L2 with I2's current Arrow direction, either entering the Dot or Exiting the Dot , of L2 . Example : + - is the +- pair across L1 , used when writing Self Term of L1 , Traversing\Entering L1 on the Left side , at the +plus , thus the Self Term of L1 is + ( + jwL1I1 ) , KVL is +pos and Ohm's Law is +pos if we determined the Induced +-polarity across L1 ( using L2's Dot with I2's Arrow direction ) as: - + , we need to use KVL Traverse in the same way that was used during the writing of L1's Self Term , thus we use - which is again Entering L1 from the Left side and the Induced term onto Mesh I1 is ( - jwMI2 ) , KVL only . I see nothing else the book is doing\saying . All the above can be done in One's head , with nothing extra to write on the diagram . Very implicite , once someone sees how to do it . Deriving the +-sign of the Induced Term does NOT use Ohm's Law , instead uses just KVL Traverse direction in the exact same way as performed when the Self Term of L1 was written . It is actually very simple to do , even though the book's sometime suggest otherwise . i have no issues wrting the initial mesh equations in Chapter 14 , of the above mentioned book . The initial mesh equations can easily be Directly wirtten with No intermediate steps, and No extra drawing on the diagram . what do you think ?

[@justadreamerforgood69]

Author name?

[@kuya445]

About the second voltage induced by the first inductor, i think it should have a sign of +- because the current enters the dotted side of the first inductor then it should follow the sign

[@evrenyigit4878]

your view helps us about circuit exam

[@DiogoPedrosaMusic]

THIS VIDEO SAVED MY LIFE!

[@LantiSpahiu]

Should have been 3(I2-I1)+ j4I1 + jI2 + 1I2 + (-j)I2? I think you forget jI2 near j4I1 in the second equation.

[@nonya1119]

I noticed that also

[@phuongnguyen-kc8hi]

Yup but he fixed that right before finishing his equation.

[@RoseHulmanOnline]

Glad to hear you found it helpful!

[@baselmarji7145]

How is the way you drew the dependent voltage source "Positive on the same side as the dot"?

[@RoseHulmanOnline]

Great, glad to hear that it was helpful to you.

[@oksky58]

thank u for clarifying the polarity!

[@vasiqshair]

The method of using dependent voltage sources is very helpful. Thank you!

[@jesusalvarezfebres6592]

excellent procedure and result.

[@aldrinjosephobis3211]

I have a question, why did in the first coil, the j4 was multiplied with I2-I1? And the second coil, why just multiply with I1? Can you elaborate a clear explanation? Tha

[@phasorsystems6873]

Hello could you test this software? Locate circuit solver on the playstore!

[@leosmi1]

shouldn't be j4(i2-(-i1)) at the first dependt source? because i1 is negative on the way with no point in 1/4H...

[@furkanarpac590]

Very clear explanations here ,thank you for the video.

[@50jegadeesan]

in mesh 2 dependent voltage should it not be j4(i1-i2) as it was done in mesh 1 .the reflection current due to mutual inductance is i2-i1

[@nalinijatwar1804]

one mistake you did in second equation. you forgot to consider inductance ( +j) ,(situated in the middle of circuit).

[@phuongnguyen-kc8hi]

nalini jatwar He fixed it right there, please watch the video until the end.

[@cizzie219]

On the j2 inductor, what if the dot was on the right, meaning i1 is exiting the dot. Would that mean the middle dependent source would be -j4?

[@phuongnguyen-kc8hi]

Trump 2016 I did that method which put the dependent source on the right of J2 and the sign was negative and positive which ha the value of J4(I1 - I2). The final answer is the same as his method putting the source where the dot is. I was confused at first but after watching many videos with different methods, I finally got it.

[@vinchester5105]

thank you just one question when we signify dependant sources (+) must look to point is it right ? İt works always does it?

[@nonya1119]

I think you missed a J2(I2-I1) in the 2nd loop equation

[@amiladrck]

Thank you! This helped me a lot :)

[@TurbidSugar19]

My hero! You saved me from my ass-some university

[@gifttsundukanimashavani3806]

in 1/4 F, when i use (1/WC)j im getting (1/4*0.25)j = 1j not -1j... how are you getting -1j?

[@RoseHulmanOnline]

Gift Tsundukani Mashavani The "j" is part of the denominator, as in 1/(j*wc), and 1/j = -j

[@ko1997ko]

you putted the signs of dependent source wrong

[@TheAdlcn]

the voltage source is in "cos" so fasor notation must be 10/_90 ??

[@zulpo]

No, you can use 10/_0rad as the source, there's no need to add 90º. Lets say you find some voltage in the circuit wich is 7/_(pi/6), in the time domain this means 7cos(4t+pi/6), its just a phase shift.

[@keyranassayida9648]

thank u so much u make it super easier for me

[@alessandrademoraisandre8729]

This helped me a lot!!!!!

[@240mains]

why the technique of Inserting dependent source ? I don't get it . Write any KVL equation of resistors , and no one inserts a voltage source in place of IR ( we could , but no one does that ) . why not just write the two Mesh equations that each contain Self-terms( as normal ) with the Mutual-terms . That's how the good books do it . Your way , the circuit diagram needs to be messed with to draw in the dependent source . Too much overhead for that approach . I am NOT liking that technique . ISBN : 0-07-027410-X "Engineering Circuit Analysis" Fifth Edition 1993 , McGraw-Hill publisher .

[@RoseHulmanOnline]

Yes, you are correct, most textbooks do not redraw the circuit with dependent sources to model the induced voltages. As a student learning this material I often found it difficult to get the voltage polarities correct, and later as a professor found that showing the induced voltages explicitly as voltage sources made it easier for my students to arrive at the correct analysis of the circuit.

[@240mains]

@@RoseHulmanOnline ok . I have found that much equation writing and analysis eventually involves a lot of implicitness . Example Reference :Node analysis , Nodes are labeled V1 V2 V3 , while each V node is + with the single Ref. node as -. +- are shown only during a First time explaining . After that , the books do NOT draw in those +- node pairs( everyone needs to Remember that ) . For Meshes , I only show I1 I2 I3 etc. in each Mesh window . I don't show the Arrows anymore, because each Arrow is implicitly known to be used in the Clock-Wise direction . It is not difficult , but eventually there are many things that become implicit , which need to be fully discussed at introductory level . When showing extra Steps , the reader should know that , that is NOT how they will eventually do it . The same circuit needs to be re-done in the implicit way . Other-wise some folks might get miss-lead in their analysis approach . You showed the analysis , but yet you don't actually do it that way. That can confuse and miss lead a First Timer . It needs to be followed by an implicit analysis so that everyone sees the real deal . The book I mentioned is very concise , Not perfect but it beats the other 2 top competing books . That book has a real Engineering approach to the discussions . The depth of technique is obvious , in the book . the other 2 competing books are : "Electric Circuits" 2nd Edition and "Basic Engineering Circuit Analysis" 4th Edition all 3 books are now in their 12th or so Editions . ( there is nothing new in the newest editions , so buy previous editions used )

[@You_Tube12355]

If we don't use dependent source we get same result ..Does it requires to use dependent source as point of view as marks

[@240mains]

@@You_Tube12355 I think some of the Techniques are NOT using the full concept of the "DOT Convention" , that is why some want to insert a voltage source . If a "Self inductance" term is + - , and we find that the "Mutial inductance" term is + - , then we know that the Mutual term "aids" the self term , and the Mutual term is written with a + . If we find the Mutual term opposes the +-polarity of the Self term , then the Mutual term is written with a -minus , for here the Mutual induced voltage acts to "reduce\opposes" the Self induced voltage There is No need to draw in\insert a "voltage source" depiction . Can you get a copy of this book : ISBN 0-07-027410-X "Engineering Circuit Analysis" Fifth Edition , 1993 McGraw-Hill publisher . It has International versions too . ( how many languages , I do not know ) That book has great depth .

[@You_Tube12355]

@@240mains book ki soft copy hay to bhejo sir please..

[@rebedmos]

Enfim eu entendi essa matéria! Bela explicação!

[@POLMAZURKA]

DLA EUROPEJSKICH / POLSKICH SPOŁECZNYCH TEMATÓW TELEWIZYJNYCH: POLONAISE I MAZURKA ESSAYS, FILMY I INSTRUKCJE: PRZEJDŹ DO INTERNETU I SZUKAJ: ACADEMIA.EDU ......... ..RAYMOND CWIEKA OGŁOSZENIE !!! Z DNIA 9/1/2018 YUBE TUBE USUNĄŁ LICZNOŚĆ FILMÓW. NADZWYCZAJNIE FILMY ZOSTANĄ ZWRÓCONE NIEKTÓRY DZIEŃ! WYŚWIETLANIE FILMÓW WKLEJ FILM - SŁOWA - ESSAY DO DOKUMENTU WORD I NASTĘPNIE KLIKNIJ i NACIŚNIJ KLUCZ CTRL NA WIDEO. ORYGINALNIE BYŁO NIEKTÓRE 47 KSIĄŻEK. I ZASADA PRZEDE WSZYSTKIM, ALE STRONA AKADEMII.EDU WYDAŁO MISSPLACED WIELE Z NICH, WIĘC NIE MOŻESZ BYĆ WIDOCZNY. PONOWNIE, NADZIEJA NINIEJSZA SYTUACJA ZOSTANIE POPRAWIONA.

[@Fairyking75]

Thanks for the great video

[@erickmillan7863]

The second equation is wrong

[@phuongnguyen-kc8hi]

Erick Millan It is correct. I try different method and the final answer is the same (verified).

[@1972hattrick]

I understand mutual inductance for a transformer would be isolated and circuit resembles a parallel look. What device is this? Why does it look to be in series?

[@iangiovaanni]

Gracias ! Thank you !

[@dilanramoscalizaya2207]

👍👏

[@mohammadyousef6374]

thank youuu

[@princemazumdar8452]

yr explaination is not understandable...as it looks like u r practising by yrself...

[@محمدسلام-ط3ط]

حبيبتي ماتت وكان ليها مكان ف قلبي جوا مليان احزان قتلتها بعد ما ختنها قوام حب الله مش ز حب نسوان