Could someone please provide a link to a website that explains how to do problems 5 and 6 of the attached assignment. The textbook for this class does not explain impedance modeling techniques.

Question

Could someone please provide a link to a website that explains how to do problems 5 and 6 of the attached assignment.  The textbook for this class does not explain impedance modeling techniques.

babyslapmafro · Answer

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irishboy123 · Answer

@radar

osprey · Answer

https://en.wikipedia.org/wiki/Control_theory Here's one such link. I think I see the problems you've got. The questions are set by the Mechanical Engineering department at Illinois, so what are electrical circuits doing in there, perhaps is part of the issue. Then there's that dreaded/wretched letter "s". Then you may just fall asleep. The letter s is, I think, the way of writing the variable in Laplace transforms. I think that the basic idea that these French people had (Fourier is another) was to design a control system, be it proportional, integral, or derivative, and then characterise it by either its time constants and/or its frequency response. The frequency response amounts to something like - you've built a control system and you want to test it out, one way of doing that is to "ping" it, and see if it OSCILLATES, or "rings". Since you probably don't want your control system shaking all over the place, if it rings, then you'll have a go with some damping. (Applies to some famous bridge disasters as well, this does.) One way of getting at the frequency response is through the Laplace transform - the variable seems to be s - another way is the Fourier transform and, if you're still awake, another way is the z transform. The above link MAY help. I wish I knew more about this, 'cos it's a fascinating area, and I've had a go at measuring the characteristics of pneumatically controlled (intrinsically safe) valve positioners as used in pipelines in the petrochemical industry - PID controllers seem to loom large there. Let me know what you think ... Bon voyage, et bon journee http://perendis.webs.com

osprey · Answer

https://en.wikipedia.org/wiki/Laplace_transforms http://people.seas.harvard.edu/~jones/es154/lectures/lecture_0/Laplace/laplace.html%20 Question 5's circuit could resonate, since there's LRC in there. Looks like the other questions are RC circuits, or physical systems which can be modelled by RC circuits. 8 looks like dashpot damping - resistances b1 and b2, b2 being in parallel with a spring constant k. I'm guessing that springs model to either electrical coils, or capacitances, or maybe both. Now I think about it I can't decide which. Some of the above is hand waving fudge, BUT some isn't. So, let's go fishing !