Solving Op Amp circuits

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  • Опубликовано: 8 фев 2025

Комментарии • 503

  • @w4gap
    @w4gap 7 дней назад +1

    Twelve years old and still one of the best Op Amp explanations out there. Awesome my fellow USN ET brother! ;-)

  • @saisivaram94
    @saisivaram94 8 лет назад +187

    In 10 minutes, you made me understand what I couldn't in 4 years of engineering! OpAmps no longer look like magic to me!!
    You are brilliant, Sir. I can never thank you enough.

    • @DanBullard
      @DanBullard  8 лет назад +49

      Thank you! I used to teach at a school where we analyzed circuits like that every day. The students got really good at op amps. Glad I could help.

    • @anders5611
      @anders5611 3 года назад +21

      That's concerning.

  • @DanBullard
    @DanBullard  12 лет назад +61

    OK, OK! It was my first one! I will do some more and have already started a positive feedback version. Stay tuned!

    • @ajeshpadmanabhan7948
      @ajeshpadmanabhan7948 4 года назад +1

      Thank you. Respect from india

    • @ericmunene8521
      @ericmunene8521 2 года назад

      Thanks alot I really appreciate you from KENYA

    • @seekinggod3174
      @seekinggod3174 2 года назад

      Very Good tutorial Dan, hope you can still share some more of your technical knowledge.

  • @lor0the0fallen0angel
    @lor0the0fallen0angel Год назад +13

    Ok, this is PURE GOLD, to me at least. This is the simplest explanation ever I heard.

  • @a.b.c.d.e...
    @a.b.c.d.e... 2 года назад +6

    For some reason, this video I stumbled upon at 3am on (another) sleepless night has just hit the spot. You always just find these videos that either repeat things you already know, or are beyond comprehension complicated and you are lost in the first two minutes.
    There are always these thoughts where I think „yeah it probably works like that“ but I just never really believe it until someone says it out.
    This Video cleared a LOT of those up.
    Thank you so, so much.

  • @AlienRelics
    @AlienRelics 4 года назад +3

    This is the best intuitive analysis of an Op Amp circuit I've seen. No complex math, just an understanding of a few simple concepts. The rules of an ideal Op Amp, Ohm's Law, and Kirchoff's voltage and current laws.

  • @shobhrajsingh1177
    @shobhrajsingh1177 5 лет назад +10

    Sir, you helped me overcome 25 years of dread for op-amps... i can never thank you enough.

  • @kirtandesai825
    @kirtandesai825 Месяц назад +2

    My fours years at engineering school could not make me understand what you did. Thanks for this wonderfule content.

  • @christophermunozcortes2890
    @christophermunozcortes2890 9 лет назад +34

    This is priceless interview material. In several job interviews I've been asked to analyze the large-signal behavior of different opamps circuits with no equations and this technique has helped me A LOT! Thanks for posting Dan!

    • @davefoord1259
      @davefoord1259 Год назад +1

      If you need something as basic as this on youtube to give you an advantage in a job interview then your training and experience is way below what you need to do that job.
      Youd be like the aeronautical engineer that thought its ok to cut heat traeted aliminium by laser cutting.
      Education these days is so poor if it results in qualified people that have that level of knowledge

    • @gaynzz6841
      @gaynzz6841 11 месяцев назад

      @@davefoord1259 based

  • @spencerrenzbalinas7250
    @spencerrenzbalinas7250 4 года назад

    Posted 8 years ago and it is more helpful than other sources i have been read and watched. Thank for this video I learned a lot about op amp

  • @AutusDeletus98
    @AutusDeletus98 4 года назад +1

    This is the first time I've fully understand how op amp works. Thanks a lot!

    • @DansFlix
      @DansFlix 4 года назад

      You are very welcome!

  • @rhettscal
    @rhettscal 10 лет назад +1

    Great tutorial! I went out and bought a HP6235 power supply just so I could recreate this lesson. It makes so much more sense now. Thanks Dan.

  • @jeffanheier2775
    @jeffanheier2775 7 лет назад

    This guy helped me understand this in 4 minutes, vs my professor who teaches this in an hour and you are still confused afterward. Thank you sir, will be coming back to see more videos!

  • @-_.---._.-_-.--._--
    @-_.---._.-_-.--._-- Год назад +1

    Thank you very much! Up till now I just remembered the formulas for different types of basic opamp circuits, but now I actually understand where they came from and am able to tackle more complecated circuits.

  • @Joyrider58
    @Joyrider58 10 лет назад +1

    Superb explanation! This came at a good time for me, I just finished my Op-Amps class and I'm still wrestling with the circuit analysis. I've been falling back on the algebra formulas, but they don't provide real understanding. The steps 1, 2 and "3 with a twist" are great. Your approach, using the three op amp rules and Kirchoff's Law, provides clear and easy to visualize insight. I've looked at many op-amp tutorials, and this is my favorite, thanks for taking the time to share your knowledge.

  • @itzeltravels
    @itzeltravels 10 лет назад +15

    I usually never write comments on youtube videos but this was a great video.
    It made so much sense and it made something that looks complicated seem very simple. Thank you so much!!!
    I have gained back some confidence in my circuit solving skills.
    You should make more circuit solving videos, a video on how to design op amps according to a specification would be great.

    • @qemmm11
      @qemmm11 Год назад

      Ideal op virtual ground (v+=v-)
      Find the Circuit vo is not complexe and then v?v? .. ! Great explain Sir 😊

  • @ronaldlijs
    @ronaldlijs 11 лет назад +1

    Hi Dan,
    Just to say that I'm 2 minutes into your video and I've paused it just to write this comment. EXCELLENT introduciton, to the point and the 3 rules here, more importantly the first one that I didn't really know about, are just great! I have seen dozens of Opamp videos, but no-one has put rule 1 into plain English: OBVSIOULY this is of GREAT help in understanding the OVERALL CONCEPT. EXCELLENT, I've learned something today, and I'm happy!!!! Keep it up!

  • @GovernmentAcid
    @GovernmentAcid 3 года назад +1

    WOW! Absolutely amazing tutorial. I'm currently back in school as a non-trad, and we're working with OpAmp circuits in my upcoming Electronics lab, and when I heard that that would be our second lab, I thought 'ACK! I don't know much about OpAmps, other than that they can be a big stumbling block', and having watched this, I feel much less intimidated. Thank you so much for posting this, this is absolutely amazing, and I'll probably be coming back to your channel as the semester goes on!

  • @vladbio
    @vladbio 12 лет назад +1

    Simple, yet very helpfull tut. Thanks a lot.
    I loved that you mentioned that there is no current in the output too. It is very important sometimes for solving the circuit.

  • @douglasthomson1989
    @douglasthomson1989 2 года назад +1

    Really great explanation of working through this op-amp circuit. Thank you very much for taking the time to do this. Cheers

  • @memirandawong
    @memirandawong Год назад

    I wish you had more of these, but then again, this video was a quantum leap in my understanding of op amps

  • @sam-pd6zi
    @sam-pd6zi 2 года назад

    The way you did this numerical is fantastic and probably the best

  • @rudyjudy7692
    @rudyjudy7692 10 лет назад +1

    Very logical step by step explanation. It has been a while since I worked with Op Amps and I am boning up for job related testing.

    • @DanBullard
      @DanBullard  10 лет назад +1

      Thanks! I wrote it to help a friend bone up for a test at GE She passed the test and got the job!

  • @alogwe1
    @alogwe1 12 лет назад +2

    Great video Dan! You are really good at teaching these concepts in a simple and elegant manner. Thank you for making this, please make more!

  • @relliart90
    @relliart90 10 лет назад

    Those people who dislike this...why? This explanation is so clear and superb!

  • @markhorton8578
    @markhorton8578 10 лет назад +1

    Brilliant, very clear, a good speed, a good amount of repetition/variance. Wish this was around when I was learning.

  • @simpego81
    @simpego81 Месяц назад +1

    Rule #2 is actually a consequence of Rule #3 IF there's a feedback that applies the output to the input until the two inputs are equal. Btw, great explanation

  • @andy-gee-2k
    @andy-gee-2k 9 лет назад +2

    you really know how to teach things. after all research, I think I really understand op amps now. thanks a lot

  • @McGuire40695
    @McGuire40695 10 лет назад +1

    I really liked the video! I'm going to a 2-year tech school for electronics. I'm in my second semester of my first year. The way they do it here is split each semester into 3 5 week modules. This module (as well as the previous one) is all digital stuff, so I'm a bit rusty with calculating these circuits. Again, thanks for the video! It's a nice refresher!

  • @michaelhawthorne8696
    @michaelhawthorne8696 11 лет назад +1

    One of the clearest explanations I have heard so far. Nice Vid Dan

  • @ERJLifer
    @ERJLifer 8 лет назад +8

    +[Dan Bullard] , you sir were the first one to break it down easy enough for me to understand this, thank you very much

  • @canhnguyen7421
    @canhnguyen7421 9 лет назад +1

    Thank you for comming and sharing with me !
    Thank one million !

  • @yimmygomez7173
    @yimmygomez7173 Год назад +1

    Holy shit! This explanation was the one I was waiting for! So easy to understand

  • @Enigma758
    @Enigma758 3 года назад +1

    This is a great video and you have a talent for conveying challenging concepts. It would be wonderful if you created more videos like this about analog electronic circuit design!

    • @DanBullard
      @DanBullard  3 года назад +1

      My newest -ruclips.net/video/UkfRYfOj3e0/видео.html

  • @DanBullard
    @DanBullard  9 лет назад +44

    I've had several people challenging me to solve this circuit or that circuit. Let's not do that. Use the technique I show you here to solve the circuit you have in mind. Assume a voltage and see what happens. You can always start with the Vout at one of the rails and see where that leads you.

    • @michaeldxyle
      @michaeldxyle 8 лет назад +2

      Dan Bullard You assumed there is the same voltage on both inputs in each case (as per your rule 2) and then found a greater voltage on the output in each case? rendering your rule 2 redundant as you stated yourself? This makes no sense? how can you have no differential between inputs(considering firstly that this does NOT use negativr feedback) (ie. 2V on each input and then magically have 10V on the output? again reaching that conclusion by assuming one input is the same as the other "unless the output is greater" then finding that the output IS greater and still taking 10V as the legitimate answer??

    • @andrewbradley1216
      @andrewbradley1216 7 лет назад +2

      I am wondering if by 'voltage supply' he means the plus/minus 10V attached to the op amp

    • @DansFlix
      @DansFlix 7 лет назад

      Yes, the power supply

  • @irgski
    @irgski 7 лет назад

    Thanks Dan for the very clear explanation.
    One suggestion would be to label the appropriate ref designators for the 3rd case equivalent circuit so the “student” can quickly identify which resistor is which.

  • @isabellet.3071
    @isabellet.3071 10 лет назад +6

    Thank you very much! This has made Op Amps infinitely easier!

  • @emorag
    @emorag 9 лет назад +20

    That was extremely clear and helpful. Thanks for posting this video.

  • @tboylu
    @tboylu 10 месяцев назад +2

    Sir this video you have been taken is just insanely good, is there any chance you could do RL, RC ,RLC and Op-Amp with RL, RC, RLC. I could not believe my eyes, how clear can someone teach something that shot time. Much love.

    • @DanBullard
      @DanBullard  10 месяцев назад

      Not likely, but I appreciate the comments. RL&C are just not that simple, although I did do a video on RC coupling.ruclips.net/video/GGAt6N-Pz9w/видео.html

  • @nivekoblivion3784
    @nivekoblivion3784 12 лет назад +1

    Dan, this video is so good. I have seen many online tutorials on op amps and this is by far the best. Why don't you upload more like this? You would become very popular very quickly. We need more lectures of this quality there are so few about.

  • @Flintsmooth
    @Flintsmooth 11 лет назад +1

    Good video. You could also mention that rule 2 applies only to closed circuits, where the output connects in some way with the - input, and the impedance therein does not prevent the max output voltage from being too low to match the input.

  • @sanjibbaral6951
    @sanjibbaral6951 10 лет назад

    That was a great video. I immediately subscribed after watching this so that I do not miss your videos. That was just great.

  • @saab93secv
    @saab93secv 11 лет назад

    Thanks! I love how clearly you explained the method (it's exactly what my prof seems incapable of doing)

  • @SravanParitala
    @SravanParitala 11 лет назад +1

    Dan! you saved a lot of time ... instead of reading and understanding, i simply understood everything... :D thanks a lot...
    Please upload more videos

  • @DanBullard
    @DanBullard  11 лет назад +6

    We went from 5V out to 10V out. That's 5V. That change happened with a 1V change on the input hence the gain of 5.

  • @almabrew8712
    @almabrew8712 10 лет назад +32

    You just save my ass for my tomorrow exam! Thanks

    • @abouchraii3411
      @abouchraii3411 9 лет назад +6

      Alma Brew i hope he save my ass too cuz i have an exam tomorrow xD

    • @DanBullard
      @DanBullard  9 лет назад +4

      a bouchra II Good luck!

  • @zackcodi
    @zackcodi 12 лет назад +1

    Awesome video sir how easily you solve the problems sir.Hats off to you sir.Thanks for uploading this video.Sir please upload some more numericals.

  • @m34u2
    @m34u2 11 лет назад

    thank you. you are a life savior! I ' ve got an exam in two days and things begin to clear up. Can't wait for your next video :D
    Regards, Vlad

  • @ajays886
    @ajays886 6 месяцев назад +1

    This was the one of best video i found,thanks ❤

  • @sarahscott8307
    @sarahscott8307 12 лет назад

    i never comment on youtube videos, but this was so helpful and articulately explained- THANK YOU!

  • @s11067528
    @s11067528 11 лет назад

    THANKYOU SO MUCH DAN...U SAVED MY LIFE...GOT MA FINALS 2MRW...ELCTRINCS...I DONT EVEN KNW THIS CONCEPT OF OP AMPS TILL NOW I HAD SOME LIGHT LOL...CHEERS MAN!! THANKYOU SO MUCH...U'R BEST!!

  • @kansasthunderman1
    @kansasthunderman1 10 лет назад

    I recall from a discussion with EE that when an op amp is used as a simple DC signal amplifier, the internal resistance of the input device itself (like a sensor coil) has to be included as part of total input resistance at the summing point.
    In that case the gain would actually be the feedback resistance / total input resistance.

    • @DanBullard
      @DanBullard  10 лет назад

      Yes, but sometimes it's hard to figure it out unless you do a static analysis like this.

  • @mohammedabdulhakabdullaabd1121
    @mohammedabdulhakabdullaabd1121 10 месяцев назад +1

    Very good explanation. Thank you.

  • @tomfahey2823
    @tomfahey2823 10 лет назад +1

    Excellent video - well paced, and very well explained.

  • @miketo8
    @miketo8 11 лет назад +1

    You were showing the switch at 2v which corresponded to a Vout of 10v. You referenced back during this time to the initial switch position at 1v with a Vout of 5v.

  • @sudiptoborun
    @sudiptoborun 2 года назад

    Nice! What a nice way of explaining op-amps! Loved it.

  • @maasteeve
    @maasteeve 6 лет назад

    Verry clear and helpfull video, I have an exam tommorow and some of these rules could be of use thank you

  • @jimadams2473
    @jimadams2473 11 лет назад

    Dan, this is an excellent op amp tutorial. Love it. Thanks

  • @indiocolifa
    @indiocolifa 10 лет назад +1

    Awesome vid, clear concepts. Thank you very much. I' would love more circuit analysis videos!

  • @WisdomVendor1
    @WisdomVendor1 11 лет назад

    Just an adjustment to your rules. If there is output feedback to the inverting ( - ) input, rule 2 applies unless V(out) is beyond the range of the rails or source.

    • @DanBullard
      @DanBullard  11 лет назад +1

      Yeah, but... It's easier to just let someone do the analysis ignoring what might be feeding back to what. What happens when you have both negative and positive feedback? Who knows, until you analyze it.

  • @UnicornTactical
    @UnicornTactical 2 месяца назад +1

    thank you so much sir! clean and concise.

  • @CatsBirds2010
    @CatsBirds2010 Год назад +1

    Thanks for posting this problem.

  • @valko007
    @valko007 12 лет назад

    Dan you made electronics loom very easy , i applaud you sir,

  • @relaxationTherapy001
    @relaxationTherapy001 11 лет назад

    superb !! I've never got this much clear explanation even in my university classes..

  • @AlienRelics
    @AlienRelics 4 года назад

    Fantastic intuitive and simple analysis!

  • @gizzzmonic
    @gizzzmonic 2 года назад

    holly crap!! compair this to the video by the indian proffesor at MIT This is now too easy. Thank you sir

  • @alphonsesynrem28
    @alphonsesynrem28 4 года назад

    My my it's really a good insight to use opamps for many different things. Thank you.

  • @welltekdiagnostics6835
    @welltekdiagnostics6835 8 лет назад +1

    Very Good Circuit Analysis ,The Way you say it ,it shows you are a teacher ,,I disagree with some of it ,but bottom line VERY Good
    Troubleshooting . and thats how we learn from each other .

  • @berkaykaya3054
    @berkaykaya3054 Год назад +1

    perfect narration.

  • @kansasthunderman1
    @kansasthunderman1 10 лет назад

    Here's a question about the "ideal" op amp.
    According to the ideal model, the open loop gain is infinite and any input would also cause the output to saturate or go full conduction. In that case, the op amp would act like a switch -IE- a solid state relay and any input would case it to turn on with full conduction.
    Even with negative feedback, it seems the op amp would still behave as a switch rather than a linear device and the whole system would be unstable and prone to oscillation.
    Accordingly, my opinion for modeling the ideal op amp is to assume the it has a very high (but not infinitely high) gain so it still behaves as a linear device, but not have the characteristic of a switch.

    • @DanBullard
      @DanBullard  10 лет назад +1

      I think that negative feedback would keep things in check automatically, no matter what the gain is. Any tiny difference would instantly be corrected. Now, toss a capacitor into the mix and watch it oscillate because the feedback can't get there fast enough especially when the gain is infinite.

    • @kansasthunderman1
      @kansasthunderman1 10 лет назад

      Dan Bullard Here's a practical experiment that might verify whether or not a device with an infinite DC gain will be stabile.
      Get a DC/DC solid state relay (a device that turns full on with a small input signal) like the one in the link below and connect it as an inverting amplifier. That is the + output is tied back to the - input so the output is 180 degrees out of phase with the input. Then apply several different levels as the turn on signal and see if the output is in fact a linear function of the input.
      www.crouzet-ssr.com/english/products/_gndc.shtml
      In my opinion, it's a good idea to avoid obscure mathematical constructs that have "infinite" quantities which can lead to confusion in a practical analysis. That's why the concept of a mathematical "limit" was introduced because infinite quantities should not be inserted in equations such as the one for amplifier gain.
      Accordingly, it would be better just to say the ideal op amp has a gain that approaches - but never reaches- infinity.

  • @psmdhaneef
    @psmdhaneef 7 лет назад

    Thanks for the help. I hope the rules you said has got no error in it.

  • @Sneee3
    @Sneee3 12 лет назад +2

    Thank you so much for this video. Keep up the great work, it's super appreciated! Greetings from Sweden.

  • @squaresolid444
    @squaresolid444 9 лет назад

    Very nice tutorial, Dan! thank you! I hope you have more tutorials on Op-Amp application, you did really good job in explaining!

  • @Rovershastalamuerte
    @Rovershastalamuerte 10 лет назад

    thank you for doing this video. Really helped me to understand a circuit i am making with the lm324.

  • @99theanonymous
    @99theanonymous Год назад +1

    Damn this video is GOLD!!

  • @MGTOW-nn9ls
    @MGTOW-nn9ls 3 года назад

    Excellent Sir. So far I haven't seen someone mentioning rule 3.

  • @Roger49-x71
    @Roger49-x71 2 года назад +1

    Thanks, a very helpful video. But could someone explain the purpose of R4 & R5 or are they simply not needed if there's no current flowing through them and no voltage drop? Thanks in advance.

    • @DanBullard
      @DanBullard  2 года назад +1

      R4 and R5 are just current limiting resistors in case something bad happens to the Op Amo.. That and in this case it allows me to make the point about Rule #1.

  • @sumitshrestha2653
    @sumitshrestha2653 9 лет назад

    I will never forget these 3 rules now..thx

  • @simonyoungglostog
    @simonyoungglostog 2 года назад

    Excellent. We need simple numbers when first learning about this.

    • @DanBullard
      @DanBullard  2 года назад

      This video got my friend Martha a job at GE. Glad I could help you.

    • @simonyoungglostog
      @simonyoungglostog 2 года назад

      @@DanBullard I recently suffered some minor brain damage and lost a lot of my maths abilities. I'm slowly relearning them, so I find electronics calculations really useful. Thanks again.

  • @guybar24
    @guybar24 12 лет назад +1

    Hi Dan , thanks for the video good job ,
    can you please explain why do we need R4 and R5 ?

  • @Avionics2
    @Avionics2 4 года назад +1

    What a beautiful example thank you.

  • @kevinbeckenham3872
    @kevinbeckenham3872 10 лет назад

    Good revision for old fogee like me.Well explained lecture.

  • @mikeoliver3254
    @mikeoliver3254 6 лет назад

    Great explanation glad I found your channel today.

  • @Melloyallo3434
    @Melloyallo3434 11 лет назад

    I'm sure you 'd get a lot of responses for videos on Diodes and BJT's and other stuff. This video was awesome !

  • @ifthekharahammad
    @ifthekharahammad Год назад

    I might be a little bit too late to join the party 😄 I appreciate the clear explanation and detailed solution you provided. Sometimes we all forget that electronics is not that complicated and that all circuits can be handled by simply adhering to a few basic laws. I have a question, and I would greatly appreciate it if you could help me understand the design decision: what is the purpose of R4 and R5 in this circuit?

    • @DanBullard
      @DanBullard  Год назад

      R4 and R5 are typically placed there to keep the current down to a minimum if the Op Amp fails, but in this case they are used to trick the observer, to see if they understand that an Op Amp consumes no current on the inputs. It's a standard ploy imposed on Employee Applicants.

    • @ifthekharahammad
      @ifthekharahammad Год назад

      @@DanBullard I appreciate your response. They were current-limiting resistors in my mind. Although it's a wonderful concept, I've never utilised them in any designs. In my subsequent design, I'll give it a shot.

  • @imabeapirate
    @imabeapirate 10 лет назад +1

    question: Why have such a complicated feedback loop? What does it accomplish?

  • @karthiknaik373
    @karthiknaik373 12 лет назад

    Really good and easy to understand .. can you please upload some more videos .. on most basic devices in electronics... opamps, transistors, mosfets ... thanks and will greatly appreciate your help ....

  • @memirandawong
    @memirandawong Год назад

    I can't say it any better that the gentleman Sai Sivaram, just below me. Brilliant!

  • @JulianJaeger
    @JulianJaeger 10 лет назад +1

    Wow! This was explained extremely bold.
    Thank you really much!!

  • @azoozpaaqa8124
    @azoozpaaqa8124 Год назад +1

    thank you you're a smart man the third rule was what I need💛

  • @amirhoosinabbassi7533
    @amirhoosinabbassi7533 Год назад +1

    Your thought me something that my professor couldn't

  • @jatag100
    @jatag100 2 года назад

    Excellent video, clear and concise!

  • @robertmcbride1491
    @robertmcbride1491 9 лет назад

    GREAT tutorial. I have to admit, I didn't understand most of it. I've got a probable reverb recovery unit op amp problem in my Marshall guitar amp, and I am hoping if you could walk me through testing the circuit, or at least the op amps, in an effort to identify the defective component? I've got a link to the schematic, and a multimeter.
    Should I just start at pin #1, measure the voltage, then try to use this video to solve for the other pin, and measure them..?
    Thanks

    • @DanBullard
      @DanBullard  9 лет назад

      Robert McBride I think it would take a bit more than that. One thing you can do is check the voltage difference between the two inputs, pins 2 & 3 if I am not mistaken. They should be the same voltage if everything is OK. Give me the link to the schematic and I can see if I can walk you through testing it.

  • @TheDonkeyKhan
    @TheDonkeyKhan 11 лет назад

    This was brilliant; thank you so much Dan Bullard!

  • @iqraafaq4328
    @iqraafaq4328 7 лет назад

    why their is only one lecture?
    thank u sir for explanation.

  • @hrnekbezucha
    @hrnekbezucha 7 лет назад

    Making opamps nice and simple. Thank you

  • @shoutitallloud
    @shoutitallloud 6 лет назад

    That's very clear explanation, thanks!

  • @robr8554
    @robr8554 Месяц назад +1

    Fantastic explanation

  • @ajeshpadmanabhan7948
    @ajeshpadmanabhan7948 4 года назад +2

    Thank you very much sir, it helped me a lot

  • @kansasthunderman1
    @kansasthunderman1 10 лет назад

    Should the ground line for the op amp circuit be connected to the chassis ground which is the green wire (or safety earth ground) for the AC power supply?
    I've seen many permanent installations (such as seismological and meteorological stations) in which the op amp's ground line was also connected to the green wire but some others did not have a connection.
    However it seems that the amp's ground itself probably should not be connected to the green wire because any current through the green wire would create a voltage and make the amp's ground line subject to erratic ground reference.
    Furthermore, the voltages in op amp circuits themselves are so low that there's no safety issue and only the chassis of 120 VAC power supply would need to be earth grounded.

    • @DanBullard
      @DanBullard  10 лет назад

      The op amp has no ground wire. Power+ Power-, In+, In- and that's pretty much it.

    • @kansasthunderman1
      @kansasthunderman1 10 лет назад

      Dan Bullard Although the IC itself doesn't have a ground pin, the non-inverting input is grounded (to provide a reference point for the differential input) and the external load at amp's output (a galvanometer for example) also has a return to ground.
      Seems that connecting the chassis ground wire to the ground line that's also used for the complete circuit might introduce noise.