PID: Using an OP-AMP to implement a PI controller.

In this video we examine a practical PI controller using an Operational Amplifier with proportional and overall gain adjust. The Laplace transform for our circuit is fully solved showing the individual proportional and integral terms.

[@botanysilkiebreeders7732]

This is incredible. There are so many concepts that are coming together in a 10 minute video.

[@jessshoes7926]

Can anyone tell me where about in an electrical engineering degree this class would be? I've been self-learning this whole time, but this video for some reason has made me feel this burning desire to go back to school. Because I have been practicing all of these things without knowing any of the terms, but it all made sense as I was hearing it, and, I feel like I am further in my learning than this. Which has given me an unexpected feeling of hope.
But now I need to know, cuz maybe I really do have a knack for this. I have spent every moment of my spare time every day for about 6 months obsessed with this stuff. It all began when I was devastated by my guitar suddenly dying on me, and decided to try to fix it. Well, I fixed it. Then, my amplifier was making noise when I connected it through one of my pedals... so I learned how to make a buffer. And it has just snowballed into a complete obsession. I find the waveform to be more easy for me to visualize than actual things. I can imagine how they would be affected by things, such as filters, or by each other, or if they are summed, differential, if I made two full rectified instances of a sinusoid, and one was inverted and also 90 degrees out of phase, then they were summed...
... you get the point. I am thinking about waveforms all day, I dream of them, I wake up and make whatever I dreamt about.
...and I basically have only needed to do the math a handful of times for each type of circuit or function. Once I can "feel" a formula or, a group of dependent relationships, I can estimate with very decent accuracy.
I have experienced this in the past, but never on this level, analog circuitry feels like the scratch my itchy brain has been seeking all of my life... I can just feel it, what would satisfy the functional loop for a given circuit, especially with a scope of the input and output, I can tell right away exactly what is happening or what needs to change
I spend all day studying, simulating, and building analog effect designs. I am nowhere near sated in my hunger for understanding. I am ravenous.
God, someone please help me.

[@ProfessorV.]

Not every college or university teaches Op Amps in depth. It depends on the instructors and program objectives. Some feel in this digital age that the focus needs to be on software platforms like microprocessors. At the college I taught at, we covered both areas. Teaching Op Amps wasn't just about learning how the devices worked and how to use them, it was also about learning how to solve circuits across a wide range of applications using math and electrical circuit theory. In my Op-Amp courses, we covered everything from the differential amplifier itself through to instrumentation, filters, PID, oscillators, all while exploiting Kirchhoff's laws, Calculus, complex numbers, and Laplace Transforms. These skills are timeless, and foster higher understanding in students about all circuit types.
When I was first learning electronics in high-school and later in university, I stumbled upon a book written by Albert Malvino entitled Electronic Principles. He is one of the most intuitive writers I have encountered in a college level text book. Since then, the book has undergone several revisions and I was delighted to find that the book was still available for purchase many years later and recommended it to our electronics program as a student text. I believe it is now on its 9th edition; our students used the 8th edition five years ago. If you can get your hands on this book, it may help you. It covers semiconductor theory, diodes, including zeners, numerous transistor types, numerous thyristor types (SCRs, Triacs), IGBTs, Op-Amps, Amplifiers, Filters, Oscillators, and Power Supplies.

[@jessshoes7926]

​@@ProfessorV.Thank you for your reply. Would you happen to have courses available for auditing?
Thank you for the suggested reading, I'll find the book.
If Analog circuitry is my passion, where would you recommend I go? It is a shame that Analog isn't taught as much anymore. I have never been able to digest an answer I didn't fully understand the implications to. So I simply need to understand the fundamentals before I can move onto more complex ideas.
I have just completed a circuit which required 8 op amps to execute my desired function. Originally 9, but I managed to simplify it so I wouldn't have to buy more IC sockets just yet ;)
It worked as designed. That was a good feeling. It took me 3 days to assemble it.
I'm gonna have to start designing the pcbs and ordering them at this point, that was way too much soldering for me ;)
What are you working on right now, if you don't mind me asking?

[@Qaidi_804]

Hi, Dr. Thanks for such a great video. I have an analog PI controller circuit through which I want to drive past the actuator but my output of the controller becomes saturated. How I could solve this problem? I am new to electronics. Also, I am not sure which output will be better for me in the end. My cut-off frequency is 2KHz. How I should analyze the output? and choose better one.

[@WalidIssa]

I like it

[@audiokees4045]

This kind of circuit is used in feedback class d amps, like icepower. Id a PID not better? faster and more stable in such amps. In a PI the setup of a feedback is such that the fall off from 1 Khz to 20 or 30 Khz is such that at 30 Khz the gain is zero, sometimes in class d I see even more safisticated system with some more complicated plot where the transform as more poles and zero.s.

[@ProfessorV.]

For many applications, adding the derivative to attain a full PID control also risks adding instability (oscillations). In your application, derivative action may be beneficial and speed response. PI controllers tend to be better behaved however for things like motor speed control but I have seen the derivative used on tachometer feedback to reduce overshoot. For an OP-AMP circuit, adding a capacitor in series with the input resistor effectively introduces derivative action.

[@binukapoudel9528]

Heyy