It could be interesting to practically show that by increasing the ramp compensation it would Turner out to be a voltage mode controlled buck converter.
سلام استاد عزیز،شما خیلی اطلاعات خوبی رو اموزش میدین ،اگه امکانش هست کاهی هم برا مثل من که انگلیسی بلد نبستم آموزش بزبان فارسی هم بگذارید،البته بازیر نویس یوتیوب نگاه می کنم ولی اگر زبان فارسی باشد چیز دیگری است،ممنون
One of the unfortunate side affects of slope compensation is its affect on the current limit. The current limit point becomes a function of duty cycle.
How much compensation is too much..that it becomes a less effective current mode control and more of a voltage mode .... I mean in terms of percentage (adding compensation)....can this be shown ?
Dear Dr Shirsavar, as always, you are the best at explaining the logic behind power electronics. I have a question. The well known SG3525 must be a voltage mode controller which is mostly used for push-pull applications. Or how is it?
I appreciate the effort that goes into videos like this, and also the desire to tell the story clearly. I'm an EE, I know a bit about switching power supply circuits. and unfortunately I don't think this video achieves its goals. The main problem is that the explanation is unmoored from even a generic diagram of the circuit to which it pertains. The presenter identifies all the signals under discussion just verbally and rather vaguely, so it's often hard to tell what is actually being discussed. For example, around 3:30 Iref is referred to as "our demand current value". Wat does that mean? This is surely a power supply producing an output voltage, (that's the demanded value), in which there's feedback that the controller uses to set the peak current of the ramp for the next cycle. I guess Iref is that peak value? But that value will change from cycle to cycle, so why is it referred to as "Iref" as though it's a fixed reference current? Either I'm unfamiliar with the terminology or I completely don't understand the circuit under examination. Later there's a comment that the subharmonic oscillation will greatly increase ripple current. Well I suppose that's just describing the alternating short and long current ramps. But what is the significance -- is the concern about disrupting the upstream supply? Or disturbing the downstream circuity, where I would have thought that voltage ripple would be a more immediate concern? Here again, being able to point to the location in the circuit that the issue applies to would be very helpful. I was very impressed with the nice animated graphs at 10:39 ... except I didn't understand what they display. What are the axes, and what are the signals plotted in red blue and green, referred to points in a schematic that I could recognize? At the point where discussion moved on to some kind of synthetic slope I was basically lost. I thought the sloped signal was the inductor current ramp, something tangible. So I didn't see how that could somehow be made synthetic. Maybe this is trying to illustrate the signals that the controller pays attention to, and the enhancement is to revise this controller input variable by adding in an additional signal or calculation. I'm not at all sure from the verbal discussion, but would have been if the graphed variables were identified with points in a schematic. (Possibly with the schematic enhanced to show stages of the controller's internal algorithm, if that's the story.) So again, I appreciate the effort, but for me, who I think might be a representative target audience, this flew over, or at least around, my head! A schematic or two to identify signals please!
Just to add --- I did see that there's a PDF with more detailed notes. I will download and read that. So no need to answer the questions I raised per se. This is more a suggestion about ways to make future videos more followable.
Hello. Thank you for this great Video. Could you perhaps tell me, which current probe you have used for measuring the current thru the Diode? Thank you.
In previous videos you show how LISN interacts with power supply loop gain... Now, with LC filter added to your power supply, what will happen when you connect it to LISN?
What happens if the circuit hasn't any earth connection? how the filter should be designed? how connect the capacitors you are calculating? I have read in ap notes from texas instruments, that not having this earth lines connections (buck converters hasn't) implies that common mode noise is equal to 0V. So they only put a differential filter. Maybe this common mode filter is only possible to implement if a third line (earth line) is there? If not, don't you need this circuit?
