I haven't seen a person ever explaining complex things so easily and neatly. I really admire your knowledge.
@sambenyaakov5 жыл бұрын
Thanks Satyajit
@carmelpule69544 жыл бұрын
This gentleman has certainly succeeded in illustrating and showing the beauty and the elegance in this area of engineering through how he relates current sensing to voltages in so many diverse manners. I appreciated all of them, but the manner in which he oriented "Vectors" to make a current passing through a path, reflect itself as a voltage," somewhere else" in the circuit, is the brilliant combination to get unity in the numerator divided by the denominator in the phase-shifting networks shown at 17:54. Sir, I tip my hat to you, my congratulations. As an old engineer, I must say that seeing this video has ended the year 2020 with great admiration of this gentleman. Thank you.
@sambenyaakov4 жыл бұрын
Thanks Carmel for sharing the mental excitements and exuberance when uncovering the beauty of electronic engineering.
@TookMe20min2findThis5 жыл бұрын
I'm an EE engineer with much experience and I can say your videos and explanations are awesome! Makes it fun to keep learning . Thank you.
@sambenyaakov5 жыл бұрын
👍😊
@basaltnow2 жыл бұрын
I totally agree, very good compilations of the must know and must do things to suceccfully have a dcdc running stable.
@PSPS4377 жыл бұрын
your videos are more than phenomenal Dr. Sam.
@sambenyaakov7 жыл бұрын
Thanks. Comments like yours keep me going.
@UpcycleElectronics7 жыл бұрын
Very interesting. Your intuitive teaching style is helping me understand dc converters much better. I'm still challenged by a lack of underlying math skills, but your helping me push my practical understanding. That's a tremendous talent for someone to communicate a subject like this without physical demonstration in a lab. Thanks.
@sambenyaakov7 жыл бұрын
Thanks for comment.
@crossbones9115 жыл бұрын
I've learned so much from you in just the last couple of days. I really appreciate your videos.
@sambenyaakov5 жыл бұрын
👍😊
@Telectronics3 жыл бұрын
Thank you very much Prof. Yaakov your active current sensing technic will help me to make a cheap measuring device on the oscilloscope !
@sambenyaakov3 жыл бұрын
Thanks for note. Happy to hear that.
@thisoldjeepcj54 жыл бұрын
Been many years since I was in school but this was a good refresher. Thanks for a good presentation. And thanks to those below who commented on some of the details.
@sambenyaakov4 жыл бұрын
Thanks
@gearstil3 жыл бұрын
Very informative! I like your videos because they show how to use the formulas, they have a mathematical approach.
@sambenyaakov3 жыл бұрын
Thanks for note
@srikanthsarjanaa80754 жыл бұрын
Dr Sam, it is really cleared lot of my doubts that's so kind of you.
@sambenyaakov4 жыл бұрын
👍😊
@vinodchavan73023 жыл бұрын
Really very helpful, you are genius of power electronics. Not only this video but all of your videos are superb. Very good explanation 👍
@sambenyaakov3 жыл бұрын
Thanks
@olivalle4 жыл бұрын
Thanks a lot for the very intersting explanation, always very sharp and clear.
@sambenyaakov4 жыл бұрын
Thanks
@shashankgaonkar25465 жыл бұрын
Fantastic Explaination about real word things.... Thank you....
@sambenyaakov5 жыл бұрын
Thanks
@xDR1TeK3 жыл бұрын
Hello prof. Sam, it is intriguing how these circuits come to existence just by a certain desire to gain functionality. It's like we can throw components in any other way and still get any output that can be tweaked through math and then operate properly. I never thought CT could be pulsed. Thank you.
@sambenyaakov3 жыл бұрын
Thank you for kind note and for sharing your thoughts.
@xDR1TeK3 жыл бұрын
@@sambenyaakov Sir It is I who should thank you. I'm unworthy.
@ANoNIMkillir4 жыл бұрын
Dear Prof. Sam, thank you for such a valuable education video in english! I made some conclusions after watching, but I'm not sure that they are correct. 1) As we need to reset core after we had pulse, we can use high enough Rr resistor. That givs us a big area under curve in a reset period, so we can reset core at wery short time. So that sensor could work close to 90% of Duty cycle. And Using HV diode i'll be safe. 2) As we should have a Rr - reset resistor the total current of the secondary will be IL*1/n=ILm+IR+IRr. So to ensure that the most part of the current is current through sensing resistor, we should have IRr and ILm as low as possible. In order to achive this, high value Rr will be nice too. 3) To ensure in low value of ILm and fulfillment of the condition: 2pi*fsw*Lm>R, i will use core material with highest "ue" possible. Thanks again for the great stuff!
@sambenyaakov4 жыл бұрын
Vasiliy,. You are correct see minute 9 and on. Thanks.
@eurosetvk2 жыл бұрын
You have pretty good kind of english. i am understand all you said even without mega english knowledge. thanks
@sambenyaakov2 жыл бұрын
Thank you! 😃
@thearithmos3408 Жыл бұрын
You explained the concepts well. Pls do more vids, it's really helpful.
@sambenyaakov Жыл бұрын
Thanks. Will try.
@ivanperezs5 жыл бұрын
Thank you for your explanations. I'm learning so much from you.
@sambenyaakov5 жыл бұрын
Thanks for comment
@ats891176 жыл бұрын
I'm watching this video again because it is one of your best. It's a shame that there are only 22,404 views!
@sambenyaakov6 жыл бұрын
Well, there aren't that many smart people in the world. Thank.
@bhargavpendurthi19715 жыл бұрын
its nice and great videos Mr.Sam. Thank you so much for sharing info and its more useful
@sambenyaakov5 жыл бұрын
Thanks
@EmmanuelAyegba7 жыл бұрын
You so good at what you do Prof that even the trolls can't touch the dislike button. I've hardly seen that happen before on youtube. Awesome. I subscribed.
@sambenyaakov7 жыл бұрын
Hi Emanuel, Thanks for comment.
@biggary6427 Жыл бұрын
It's very useful, well-done for explanation
@sambenyaakov Жыл бұрын
Thanks
@binzhao25446 жыл бұрын
Dear Prof. Sam, thank you very much for your video. I am wondering whether 'n' is missing in the equation of Bmax at 13:59. Thank you so much.
@sambenyaakov6 жыл бұрын
Dear Bin, Thank for comment and pointing out the omission. You are of course correct. I hope that viewers of this video will notice your remark.
@petergriffin7604 жыл бұрын
Final expression for Bmax actualy do have 'n' term in numerator, corresponding to current Iav. Where else you suppose to put it? Seems correct to me now
@kabandajamilu90364 жыл бұрын
So nice you have made me informed may God reward you
@sambenyaakov4 жыл бұрын
Thanks
@alexwang0077 жыл бұрын
Thank you very much, sir, for the info you have provided! Very awesome teaching, would certainly recommand to others.
@keithking19855 жыл бұрын
This is my first video of yours if seen and I loved it.. I'm going to subscribe straight away. 👍👍 brilliant
@sambenyaakov5 жыл бұрын
Thanks
@basaltnow2 жыл бұрын
very good video, I nirmally use gall sensors with adequate bandwith, but yes once also used a current transformer.....just to had it done in oractice once.
@sambenyaakov2 жыл бұрын
Thanks for sharing
@hariharank23634 жыл бұрын
Very informative, excellent sir...
@sambenyaakov4 жыл бұрын
Thanks
@nosuchthing47896 жыл бұрын
Amazingly clear explanation! Thank you!
@sambenyaakov6 жыл бұрын
Thanks
@MORAL19525 жыл бұрын
Excellent. Especially in the final approach. Thank you.
@sambenyaakov5 жыл бұрын
😊
@qqqqqq66867 жыл бұрын
Question to 1:20 - should not this voltage spike appears at the end of the current pulse? not on the beginning?
@sambenyaakov7 жыл бұрын
It will appear at both the beginning and end (high di/dt). I neglected to show the negative spike. Thanks for pointing this out.
@power-max3 жыл бұрын
I just learned about the last method and was exploring the time domain characteristics of it in LTspice, but I kept having to fudge the RC time constant value! After an hour of head scratching I realized LTspice was applying a default DCR of 1mOhm to my inductor, which i was not accounting for! Gees I thought I was doing my unit conversions wrong because I kept coming up being an order of magnitude off lol. It's a really neat method, but looks like it can't be very accurate since the ESR of the inductor is a function of frequency of temperature, as is the inductance, causing the output of the RC filter to be under or overdamped with variation to L (like with large DC current bias or flux bias in the core)
@sambenyaakov3 жыл бұрын
Good points. Thanks for sharing. If not a member: welcome to join www.linkedin.com/groups/13606756
@ovalwingnut4 жыл бұрын
RATED: 💡💡💡💡💡 9 out of 10 ELECTRONS liked this video. Thank you Professor 👍😁 SUBBED!
@sambenyaakov4 жыл бұрын
Thanks, but can you decipher this for me?
@Azagro7 жыл бұрын
Very interesting video! I have only thought about putting a single winding on the main power transformer, using the existing magnetic flux and the seperate 1:1 transformer using the existing input current to switching circuit. However, this brings a lot of new functionality to the table! Thank you. Also, what does j and omega stand for in 18:00 ?
@sambenyaakov7 жыл бұрын
As I think I have said in the video. I am doing the analysis on any one of the Fourier frequency components (omega) of the inductor current and using the complex representation (j) of the impedance and filter.
@Azagro7 жыл бұрын
Oh that might be, I must have missed it, excuse me! Thank you!
@sambenyaakov7 жыл бұрын
All the best
@TSulemanW6 жыл бұрын
Nicely and simple explaination give easy understanding
@sambenyaakov6 жыл бұрын
Thanks
@jacobs72812 жыл бұрын
Very Good Video detailing the reset mechanism for CT. @7.10 What type of waveform we can expect across burden resistor whene Ct is not resetted propley or volt sec criteria not met. A sharp return zero instaed of sinusodal return? along with ringing?
@sambenyaakov2 жыл бұрын
Thanks. Good question. With no reset to core, the circulating current will keep rising, the inductance will drop and I suspect that there will be either a thermal run away, or the circuit will stabilize with a much higher resonant frequency.
@jacobs72812 жыл бұрын
@@sambenyaakov thank you for the quick reply . My question was more like there is is burden resistor present and what type of wave dorm I can expect , my under standing from your explanation is that reset will still will be in sinusoidal nature but with higher frequency
@newDAVIDnew4 жыл бұрын
Thanks, I was wondering if you can simply use an extra winding on the output inductor in order to measure the current with a pulse transformer for a dc/dc converter?
@sambenyaakov4 жыл бұрын
A winding on an inductor does not sense current it senses voltage .
@rayachotybharathkumar2683 жыл бұрын
This is a wonderful video professor🙏. I'm watching it for the 3rd time and this time, I completely understood what exactly you're trying to explain. There are a few questions that arose in my mind while watching this video 1. In 1st slide: why don't we have a negative voltage spike when current fell to zero abruptly? 2. How exactly does ultra costly 50MHz (AC+DC) current probes work? I'm saying ultra costly coz atleast they are too expensive for individuals to own. 3. Can I make a low cost high frequency current probe by separating out the measurements for AC and DC signals? Using cheap low bandwidth hall effect sensor for DC component and using a pulse current transformer with a range of output resistors to avoid core saturation? Do we get accurate readings by adding these components? Also, is there a better way for doing this accurately at lower cost?
@sambenyaakov3 жыл бұрын
First slide? please indicate minute of video In commercial current probe the HF portion is indeed based on the AC transformer action.
@rayachotybharathkumar2683 жыл бұрын
@@sambenyaakov Slide 9-4. Time: 01:01
@sambenyaakov3 жыл бұрын
Yes indeed there will be a negative voltage spike which is not shown. Thanks for pointing this out.
@fakduken97753 жыл бұрын
Thanks, very nice explanation.
@sambenyaakov3 жыл бұрын
Thanks
@darshanchirke37295 жыл бұрын
Very beautiful explaination sir. Thankyou.
@sambenyaakov5 жыл бұрын
😊
@gspowersolutions3 жыл бұрын
Awesome video. Thanks 👍😊
@sambenyaakov3 жыл бұрын
Thanks
@zikermu5 жыл бұрын
Really Interesting .Thanks a lot
@sambenyaakov5 жыл бұрын
Thanks
@amritpattanaik2037 жыл бұрын
i really the way you describe.. Thanks for this video
@sambenyaakov7 жыл бұрын
Thanks for comment
@prasad91053 жыл бұрын
Thanks. Excellent Sir!
@sambenyaakov3 жыл бұрын
Thanks
@ivanperezs4 жыл бұрын
Great as usual
@sambenyaakov4 жыл бұрын
Thanks again!
@Graham_Wideman4 жыл бұрын
12:55 "the impedance of (the magnetization inductance) must be much lower than (the load resistance). I think you mean higher, not lower.
@sambenyaakov4 жыл бұрын
Hi Graham, thanks for the the correction of the slip of the tongue. Indeed, the impedance of transformer need to be larger than the resistor as written on slide, and the current lower, which is also indicated.
@wolky19074 жыл бұрын
Sir what do you think of measuring current through mosfets rdson? In very high current drive circuits, not adding one more lossy component and measuring through rdson is very attractive. any advice or contrary idea? thanks in advance.
@sambenyaakov4 жыл бұрын
This is a good approach. The down sides: temp and current dependence of Rds(on) and the extreme difficulty to implement it in a discrete circuit. Suitable for a monolithic design.
@namederek36104 жыл бұрын
Nice video but If it's open circuit CT how can you make a relationship between output current of the CT in terms of measured output voltage?
@sambenyaakov4 жыл бұрын
Open circuit voltage depends on magnetization inductance.
@namederek36104 жыл бұрын
@@sambenyaakov Wow! you're a legend I didn't think you would reply coz the video was 3years ago. Thanks :)
@gregorymirsky87075 жыл бұрын
Sam, the secondary voltage v is a derivative of the primary current. If the primary current has a DC component (it is hard to imagine a conventional converter that does not), it should be counted too, since it magnetizes the magnetic core, moving the setpoint on the B-H curve closer to the saturation. The derivative ignores the DC current component. Integrating the volt-second product disguises the real process in the core, since it deals with the voltage value obtained AFTER taking the derivative and thus missing the effect of the core magnetization by the DC current. Therefore the statement "Pulse transformer operation is limited by voltage NOT CURRENT" 14:28 is incorrect since it actually is limited by the total primary current - AC + DC, flowing through the primary winding.
@sambenyaakov5 жыл бұрын
Dear Gregory, The pulse current sensor is intended to measure a pulsed current. For example in the Drain of a switching transistor, or in the line of a diode. This is the application. In this case, the core is magnetized during pulse time and demagnetized during the off time. What matters then, in terms of saturation is the volltsec imposed on core core, conveniently measured at secondary. Being a transformer, the primary and secondary currents during pulse are canceling each other so what is left is the magnetization current, not the actual pulse current. Regards Sam
@sambenyaakov5 жыл бұрын
One more point (added to first reply which may appear as second) . The output voltage is NOT the derivative of the primary current! During the pulse time I2=I1/n (save the magnetization current). So V2=I1*R/n
@gregorymirsky87075 жыл бұрын
@@sambenyaakov Dear Sam, the secondary voltage v is a derivative of the primary current. If the primary current has a DC component (it is hard to imagine a conventional converter that does not), it should be counted too, since it magnetizes the magnetic core, moving the setpoint on the B-H curve closer to the saturation. The derivative ignores the DC current component. Integrating the volt-second product disguises the real process in the core since it deals with the voltage value obtained AFTER taking the derivative and thus missing the effect of the core magnetization by the DC current. Therefore the statement "Pulse transformer operation is limited by voltage NOT CURRENT" 14:28 is incorrect since it is actually limited by the total primary current - AC + DC, flowing through the primary winding and defining present flux density B." I have a MathCAD analysis of a current transformer from the point of view of the pulse top transfer fidelity. If you have MathCAD I can share this file with you through a personal email.
@gregorymirsky87075 жыл бұрын
@@sambenyaakov Dear Sam, yes, it is intended but the DC current is still present even if you put the current transformer in the drain circuitry directly.
@sambenyaakov5 жыл бұрын
Dear Gregory It is a common mistake to think that a transformer can not transfer an average DC current. This notion is incorrect when it comes to switched circuits. See for example a forward coverter. There is an average DC current component in the primary! What is not allowed is an average DC VOLTAGE on any of the windings. As for the pulsed current transformer explained in the video, it is widely used in the industry. Challenging it is like a person seeing a camel and exclaiming: there is no animal like this😊 In a switched NONLINEAR circuit you need to consider each segment by itself. If you will do that, then during the pulse time the primary current is balanced by the secondary current and then you have a magnetization current which is discharged during the off time. So nothing is violated here.
@vishwanathhebbalad59673 жыл бұрын
Does power electronics designing domain have future.I am interested to work in this domain and suggest me which domain is best and have future.
@sambenyaakov3 жыл бұрын
Yes, definitely. EV area is growing fast.
@ruixiong52374 жыл бұрын
It really helps. Thanks.
@sambenyaakov4 жыл бұрын
Thanks
@johnconrad54875 жыл бұрын
the last one with Vout = I Rs G sounds great... but Delta Rs is HUGE over delta Temperature. So now you have to compensate for that.
@sambenyaakov5 жыл бұрын
But quite predictable.
@mikeguitar97693 жыл бұрын
Here’s an idea. The “differential amp” @19:44 could be implemented in the usual way with an op-amp and 4 resistors, where the gain is the ratio of resistors. Use copper (or iron/steel) wire-wound input resistors (with a tcr similar to the inductor) that are thermally connected to the inductor. This ought to decrease the amplifier gain as the inductor heats up.
@QoraxAudio5 жыл бұрын
Does the diode leakage current has any significant effect on the measurement results?
@sambenyaakov5 жыл бұрын
It is usually insignificant being much smaller that the measured currents.
@QoraxAudio5 жыл бұрын
@@sambenyaakov Okay, thanks for the reply.
@BorisGrishenco3 жыл бұрын
Thank you for a video!
@sambenyaakov3 жыл бұрын
Thnks
@johnyradio27 жыл бұрын
Say i have 2 in-phase AC signals, at 200 kHz. i would like to obtain a 200 kHz AC output with current equal to the current-difference between the two input currents. I don't desire a DC or proportional-voltage output. Can i use the CT or other methods? Thx!
@sambenyaakov7 жыл бұрын
Yes, you can definitely use a CT (one core) with two opposed windings. Remember that the load of the third output winding should be such that the voltage on it will not saturate the CT core. Good luck.
@johnyradio27 жыл бұрын
Sam Ben-Yaakov Thx! could I achieve the same using a transformer with 3 windings?
@sambenyaakov7 жыл бұрын
You need in any case three windings 2 for primaries 1 for output.
@brokensword50427 жыл бұрын
RC=L/Rs Very useful equation when the coil wire DC rezistance is steady. Maybe need to compensate the temperature coefficient of the copper wire for high current values? Do you think a NTC in place of(or in parallel to) R would do ? Thanks Mr. Yaakov for the nice videos.
@sambenyaakov7 жыл бұрын
You are correct there is a temp sensitivity. Inductor wires are normally made of copper which has an appreciable temp coefficient. R is NOT added! it is the resistance of the wire!
@brokensword50427 жыл бұрын
I meant R the resistor in serial with a capacitor across the inductor. 17:45 What correction method would you suggest to get accurate (free from temperature ) current feedback from the inductor? (other than larger wire diameter) Thanks.
@sambenyaakov7 жыл бұрын
Sorry. I misunderstood. Good idea, perhaps somebody else already did it? I don't know. The problem of temp tracking is that in real systems the temp inside an inductor winding might be much higher than the ambient. At any rate, in most applications, there is no need for high accuracy in the measurement of inductor current. This signal is normally used for current feedback and there is no need for precise current measurements there.
@mikeguitar97693 жыл бұрын
Here’s an idea. The “differential amp” @19:44 could be implemented in the usual way with an op-amp and 4 resistors, where the gain is the ratio of resistors. Use copper (or iron/steel) wire-wound input resistors (with a tcr similar to the inductor) that are thermally connected to the inductor. This ought to decrease the amplifier gain as the inductor heats up.
@vickys14605 жыл бұрын
Thank you for clearing sir. Sir I am calculationg reset time of CT. Which parameters are important to calculate it. What I understood is ( Secondary side inductance, shunt capacitance are enough to calculate reset time.) Shall I measure L & C at switching freq
@sambenyaakov5 жыл бұрын
Indeed.
@gregorymirsky87075 жыл бұрын
Vicky, at 9:57 there is a very good schematic, comprising a Zener diode in series with a blocking diode shown. As professor Ben-Yaakov mentioned, this schematic is intended for the reset time control. The reset time can be defined as Tres=Lsecondary * Isecondary / (Vzener+Vdiode) The volt*second integral should remain intact. Therefore, for shorter Tres you should select a higher voltage Zener diode and don't forget about selection of a higher voltage blocking diode.
@wliamwlbwang835410 ай бұрын
why the dc current will flow though the diode but through the Lm, the resistor of Lm is zero to the dc.
@theoryandapplication71977 ай бұрын
thabk you
@sambenyaakov7 ай бұрын
👍🙏
@johnyradio27 жыл бұрын
Superb!
@Electromaniaworld7 жыл бұрын
can you comment sometime on current measurement at very low values in nano and micro amps
@sambenyaakov7 жыл бұрын
Look up LPV821
@zhengyangchu91257 жыл бұрын
could you please upload some videos of application examples in industry?
@sambenyaakov7 жыл бұрын
Will try
@Netsroht724 жыл бұрын
Beautifull...at 19:40...
@sambenyaakov4 жыл бұрын
👍😊
@nirmalkumar-bf3mz6 жыл бұрын
Hi I need VTG. Sensing circuit per elect.
@muruganjai8276 жыл бұрын
sir any simple way to identify the phase sequence of three phase supply
@mikeguitar97693 жыл бұрын
Maybe connect a motor and see which way it turns?
@sudoall4 жыл бұрын
You should add a practical demo for this ... showing the advantages at different frequencies and selecting actual parts , hence giving a reasonable design pattern for people to implement this in their designs... good presentation though thanks !
@sambenyaakov4 жыл бұрын
David, Your the first! Out of the 54K or so who have watched this video, you are first and only to complaint: "You should add". I guess all others appreciate the time I take to prepare these videos sharing them for free to all.
@walterbunn2806 жыл бұрын
Ehh.... this is quite interesting but i'm not sure about some things.... My main question is what happens when you use a step down transformer instead of a step up transformer? Most of the compensation/error mechanisms mentioned herein are caused by measuring a voltage that has been stepped up and the resulting reverse voltage conditions that naturally occur because of that. I suspect that the answer is "impedance", but changing the voltage seems like a guaranteed way to mis-match said impedance, so perhaps not.
@sambenyaakov6 жыл бұрын
Hi. You seem to have missed the point. No voltage is stepped up. The purpose of the pulse transformer is to measure current. If it will be a step down then: 1. The output current will be LARGER than the primary current, 2. The impedance reflected to the primary will be large, disturbing the current path and dissipating power.
@dalwindersingh94558 ай бұрын
Thanks Sir
@sambenyaakov8 ай бұрын
👍🙏
@faidularcs6 жыл бұрын
Thankyou very much
@AltayBrusan5 жыл бұрын
thanks
@SINHRO-FAZA2 ай бұрын
Я всё же придерживаюсь мнения, что резистивный шунт, это элемент, наиболее точно показывающий эквивалент проходящего тока..
@MrSummitvilleАй бұрын
Good luck at 50 amps. The shunt will be *HUGE* . And you need low inductance.
@jeffryblackmon48466 жыл бұрын
Thank you!
@omaraaziz67063 жыл бұрын
Thank you very much
@sambenyaakov3 жыл бұрын
Thanks
@ForceTranqАй бұрын
Thank you
@sambenyaakovАй бұрын
👍🙏
@cyruschady20534 жыл бұрын
Hard to understand. Please explain in detail and speak a little slower. Thanks.
@sambenyaakov4 жыл бұрын
Play it at 0.75 speed. I am sure that watching it again will help you out.