Timeline for Deliyannis-Friend design: where is my mistake?
Current License: CC BY-SA 4.0
21 events
| when toggle format | what | by | license | comment | |
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| May 28, 2023 at 14:47 | vote | accept | Granger Obliviate | ||
| May 20, 2023 at 13:36 | comment | added | periblepsis | Never mind. It's the C1 C2 problem again. | |
| May 20, 2023 at 13:13 | comment | added | periblepsis | Your Kp also seems to have a problem. It doesn't seem to have a difference of zero with what I come up with. It should, of course, but it doesn't. I'll have to spend a little time to see exactly why. (I'm taking into account the -1 power.) | |
| May 20, 2023 at 13:03 | comment | added | periblepsis | Okay. Thanks. (Doesn't look updated yet to me but your point is still taken.) Then I will proceed spending some more time. Just wanted to be sure. | |
| May 20, 2023 at 12:36 | comment | added | Granger Obliviate | Hi @periblepsis, around 5-10 minutes ago I have updated my solution. Yes in my Q value the capacitors are swapped although, as they are equal and always appear on a ratio it does not affect the result. | |
| May 20, 2023 at 12:29 | history | edited | Granger Obliviate | CC BY-SA 4.0 |
added 2064 characters in body
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| May 20, 2023 at 12:25 | comment | added | periblepsis | I think I found a problem with your Q. Care to recheck your result? Last term, by the way. The other two look right to me. | |
| May 19, 2023 at 21:44 | answer | added | Tesla23 | timeline score: 2 | |
| May 19, 2023 at 8:06 | history | edited | Rohat Kılıç | CC BY-SA 4.0 |
formatting
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| May 19, 2023 at 7:58 | answer | added | LvW | timeline score: 2 | |
| May 19, 2023 at 5:32 | history | edited | user319836 | CC BY-SA 4.0 |
Equation delimiters
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| May 19, 2023 at 1:49 | comment | added | Granger Obliviate | Thank you. I will also move on writing some text. This is for my thesis and I have been stuck all week with the work to deliver at the end of the month, so I really need to move forward and stop hitting my head on the wall. Thank you in advance for your time and your help. There might be a design algorithm somewhere, I'll actually open a question asking. I know that here by dividing Kp with Q I am losing a degree of freedom and beta can't be arbitrarily chosen... | |
| May 19, 2023 at 1:46 | comment | added | periblepsis | I'll take a look at it, then. Might not be immediate (today), though. | |
| May 19, 2023 at 1:43 | comment | added | Granger Obliviate | @periblepsis this seems to be a very difficult problem, no one is being able to help, I don't know what to do. | |
| May 18, 2023 at 2:51 | comment | added | periblepsis | The author claims (but doesn't demonstrate in the short letter) that sensitivity of Q to components in the filter is minimized by setting the two capacitor values to the same value. (I don't want to bother with the differential equations right now to confirm the claim.) So I can see why your approach (or that gathered up from someone else writing on the topic) of setting the two capacitor values to be the same may be a correct part of the algorithm. I'll add a +1. Maybe someone will save us both some time. | |
| May 18, 2023 at 2:44 | comment | added | periblepsis | By the way, I used the authors nomenclature for \$C_1\$ and \$C_2\$, which is the opposite of your writing. And I use his left-side naming of \$R_a=R_f\$ and \$R_b=R_g\$, where yours is on the right side. So if you want to use any of what I just wrote in the prior comment, you will need to look at his 1(c) schematic that I already posted to you above. I chose not to use your schematic, preferring his. | |
| May 18, 2023 at 2:37 | comment | added | periblepsis | If I set \$\tau_{_0}=R_1\,C_2\$, \$\tau_{_1}=R_2\,C_1\$, \$\tau_{_2}=R_1\,C_1\$, & \$\eta=\frac{\tau_{_0}}{\tau_{_1}}+\frac{\tau_{_2}}{\tau_{_1}}-\frac{R_a}{R_b}\$. Then I get \$K_p=-\frac1{\eta}\left(1+\frac{R_a}{R_b}\right)\$, \$\omega_{_p}=\frac1{\sqrt{\tau_{_0}\,\tau_{_1}}}\$, \$\zeta=\frac12\eta\sqrt{\frac{\tau_{_1}}{\tau_{_0}}}\$, & \$Q=\frac1{\eta}\sqrt{\frac{\tau_{_0}}{\tau_{_1}}}\$. The author then sets \$r=\frac{R_1}{R_2}\$ & \$q=\frac{C_2}{C_1}\$ (using your naming, which is the opposite of his) and then moves on to define similar \$\tau\$ terms but using \$r\$ and \$q\$, instead. | |
| May 18, 2023 at 2:29 | comment | added | Granger Obliviate | @periblepsis I am still not being able to figure this out, this is horrible | |
| May 18, 2023 at 1:03 | comment | added | periblepsis | (Hmm. Just noted a mistake by the author. Or, at least it looks like one to me right now.) | |
| May 18, 2023 at 0:40 | comment | added | periblepsis | Did you start out by reading "High-Q factor circuit with reduced sensitivity" by T. Deliyannis, 1968, from Electronics Letters, 4(26), 577? (It's what I'd do, anyway.) Note figure 1(c) from the paper. | |
| May 17, 2023 at 23:54 | history | asked | Granger Obliviate | CC BY-SA 4.0 |
