AC Theory: How to Find Resistance, Impedance, Inductive Reactance and Inductance of a Coil

[@jamesward9570]

Brilliant series

[@GSHElectrical]

Fantastic as always 👍

[@JoeRobinsonTraining]

Thanks Gary.

[@ianclark8194]

Absolutely THE best resource for principles on the internet.....

[@JoeRobinsonTraining]

Aw, thanks Ian, you're too kind. 👍

[@robertfarkas5050]

Joe, you are a Legend, thank you for the videos. They are clear, concise and accurate. Job brilliantly done Sir !

[@no_short_circuit]

Thanks Joe, this video follows nicely from the last in the AC Theory series. I have to accept from you that your students need fairly detailed explanations of how to transpose in basic algebraic formula. I would have thought that anyone studying AC theory at this level would have already had those skills. Looking forward to next Sunday.

[@JoeRobinsonTraining]

You would be staggered at the lack of mathematical ability that some learners join us with, even basic algebra can be challenging for them. It's a large part of what drives me to make content for my channel.

[@abdulmumin6251]

@@JoeRobinsonTraining Joe im one of them hand on heart I've learnt more from your videos in 4 weeks than I have learnt in class this whole year. Wont lie if I don't understand something I'm to shy to say. U explain everything so well. I didn't know algebra formulas on impedance or lighting stuff or star delta phase current inductive reactants im absolutely buzzing just wish I found ur channel a year ago im playing catch up now. Have 6 weeks to do a years work

[@deanedgx]

great series of videos Joe. I'm refreshing my elec theory in order to try and get back into elec engineering. cheers.

[@JoeRobinsonTraining]

Cheers. Glad they're helpful!

[@dja.selekta]

Fella, You’re a godsend. Recently started unit 202, I had been watching these videos before I enrolled.. Thank you. I owe you a few pints 😂

[@JoeRobinsonTraining]

You owe me precisely nothing sir! 😃 But if it brings you joy, feel free to buy me some coffee. ☕😊 www.buymeacoffee.com/joertraining

[@tedhayton2302]

I just identified the inductance of a large unlabelled radio PSU choke using this method with a variac for the AC supply. Concise and brilliant Thank you.

[@eliemutia4620]

brilliant explanation sir

[@JoeRobinsonTraining]

Thank you kindly. 😁

[@stikndip]

As I understand it, the resistance and the impedance in the coil would be considered to be in series as your Pythag calculation describes an impedance triangle. Correct me if I'm wrong. Brilliant content btw!

[@kabandajamilu9036]

So nice and educative sir

[@flyhighwithyourdreams.2132]

hello joe. we have one 3 Ph Motor and that parameters are 22 kw, 40.9 A, 415 V, 50 Hz. How to find Apparent power, Power factor, Reactive power , Total impedance, resistance and inductive reactance Value. note : We measure resistance value 0.44 ohm (Ph-Ph), Inductance 7.2mH (ph-ph) Motor was Delta connection.

[@JoeRobinsonTraining]

Great question, bit tricky to answer in the comments, may do this as a video. 👍

[@Sergey3023]

@@JoeRobinsonTraining will be waiting!

[@wadib3eed7]

So interesting information .

[@JoeRobinsonTraining]

Thanks very much, stay tuned for more!

[@hasansertkaya3808]

Thanks for the video, it has been absolutely amazing help! However, I have a question which I’ve been struggling to find an answer to. How do I find inductive reactance (XL) and inductance of a coil (L) if I am only given A.C voltage, Frequency and resistance. As I’ve learned from this video, all that is linked to one another and I need resistance of a D.C circuit as well to calculate the impedance so I can move forward with the question?? Any help would be very much appreciated!

[@gbelectricks]

Hiya Joe, can you tell me the make and model of the calculator you use in your videos. I’m looking into buying a new one and this seems one of the best. I like the feature, that you can punch in an entire formula and basically let the calculator do the work! Thanks 🙏

[@JoeRobinsonTraining]

Hiya, it's the Casio fx-85gt plus, but it's been discontinued now, the newer model is the fx-83gtx (no solar panel) or the fx-85gtx (solar panel). 👍

[@matthaddock6490]

Great material Joe 👍🏻

[@JoeRobinsonTraining]

Thanks Matt, really nice to run into you again today. 👍

[@jacksonli6710]

so helpful~~~~~~~~~~~~~~~~~~~~~~~~ thanks

[@JoeRobinsonTraining]

You're welcome!

[@MrDangadave]

Ah Dang it, I got stuck when calculating the impedance, I didn't take into account the AC and DC current differences, need to swot up on that not to make the same mistake again. Cheers Joe.

[@JoeRobinsonTraining]

Nice one for trying, I actually make a small mistake at the end of the follow up video to this one. It happens!

[@waynegram8907]

The Inductance of the coil is at 142H but at 50hz, if you choose another frequency like 120hz or 1Khz the inductance of the coil will be different. So the same coil can have different inductance of the coil values based on the frequency?

[@markrowland5393]

Excellent.

[@JoeRobinsonTraining]

Thanks Mark!

[@myway852]

Great content

[@jarrodreeves2329]

Hopefully someone can help me here, im a little confused. In the video Joe mentions the Impedance of the coil is Z = Vac / Iac? Thought the formula was z = square root of R (squared) + XL (Squared) ??

[@craigcampbell7638]

Thank you

[@JoeRobinsonTraining]

My pleasure. 👍

[@sajicherian539]

Many thanks

[@edwind7761]

If the coil is energized with DC you get its resistance, if you energize it with AC you get its impedance. With those values you can calculate XL, FP and the capacitor. It's clear and very smart but .. How can you get those values from a heavy-duty engine? Sometimes you don't have the nameplate. Is there any way to calculate them? Thanks for everything :)

[@wadib3eed7]

I have a question , if the voltage source 240 AC and the current flowing through the inductor is about 4 Amp , the impedance will be 60 ohm , how to figure out the inductance of the coil and its resistance? The question, if i want to design an inductor for 240 AC and i want to know the inductance and its dc resistance but i supposed the current flowing is 4 Amp and the is impedance 60 ohm .

[@JoeRobinsonTraining]

I think we'd need at least one more piece of information to answer that.

[@wadib3eed7]

@@JoeRobinsonTraining Suppose we have impedance 60 ohm , and we don't know inductance and resistance , i think if we need to design inductor let us suppose the power factor , as you know the inductor is not pure inductor PF=0.85 , cos(thita)=0.85 PF=R/Z R=0.85*60= 51 Ohm Z^2=R^2+X^2 Xl=31.61 ohm Xl=2*pi*F*L F=50 Hz L=0.1 H But i have another problem the electrical formula of inductance is L=m*(N^2)*(A)/l M= permeability N=number of turns A=coil area i=coil length but the equation has missing part , that part wire size to carry the current . i searched in google but there are more than one formula . any way , what about my assumption?

[@masoudmostajer319]

very helpful I want to design a snubber for inductive load can you help me?

[@koponstanley4]

(The multimeter looks nice)

[@AndrewCook7]

Jo Where does 2 pi f L Originate from

[@ahmedelmekawy6555]

I need this playlist pls

[@frankrose4657]

I'm confused to why you use the DC and the AC readings to figure out inductive reactants

[@mohammadghobakhlou47]

Excuse me, Its very strange for inductance value. 1.42 H is veryyyyy large value. Is this true value?

[@bartom309]

is 0.0424H 424mH ?

[@sergejpanov5543]

Mathematical inductor's value is 1.42H (big value) and the real measurement is..???