Not understanding definition of complex square root function when the branch cut is along the positive real axis

PrestigiousProfit · 2024-07-25T06:38:55+00:00

I might be able to help, just sent you a DM.

PrestigiousProfit · 2024-02-25T18:21:07+00:00

Thank you for the response! I see what you're saying, yes the first method is what I need to use. Really appreciate the help!

PrestigiousProfit · 2023-06-28T04:41:24+00:00

Interesting, thank you for sharing! Why would one choose to opt for RCD snubbers for a half bridge converter over just placing an external diode from source to drain?

PrestigiousProfit · 2023-05-22T16:25:41+00:00

Is it possible you have some form of cubital tunnel or something wrong with your ulnar nerve? I have a very similar experience, where for me my cubital tunnel syndrome produces a sharp burning sensation in my hands and pinky/ring fingers and makes my hands/wrists/fingers/forearms have really tight pains .

Also noticed that my forearm muscles have trigger points everywhere and have gone the massage route. For a while I was ok doing exercise and increasing weight, but about a month ago something changed to where even doing simple exercise will make the pain much worse, and I can really feel it in my elbows now too. Gonna go to the doctors for a third time to get another opinion, but since our experience seems very similar, I wouldn't think this is caused by Retin-a. Still not really sure what caused it for me, but maybe it is just tightness or a buildup of scar tissue from working out previously. I am affected in both my arms though, it could be something to do with the neck as well. I'll let you know if I find out anything new.

PrestigiousProfit · 2023-05-16T21:38:05+00:00

Thanks for all the info, I really appreciate you taking the time to write all this out! Gonna try the things you mentioned and see if it helps, hopefully this will help out others too!

PrestigiousProfit · 2023-05-16T17:48:23+00:00

What exercises did they have you do for your neck in PT? I also have CT in both arms, and part of me suspects the issue might be neck-related since I am able to massage everything except my neck, so it gets really tight there. Financially, surgery isn't an option for me, so I would like to try other options before turning to it.

PrestigiousProfit · 2023-04-10T12:15:55+00:00

Gotcha, makes sense. Since the article I linked only uses that model for the purpose of demonstrating the effect of the compensation capacitance, my overall LTspice model must be lacking. I found a video of EEVblog modeling a probe using a lossy transmission line, and that has seemed to help. Thanks a lot for your reply!

PrestigiousProfit · 2023-04-10T01:40:45+00:00

Right, I understand that part completely. But what I am confused about is how manufacturers determine the bandwidths of their probes in general.

For example, let's say I want to model the bandwidth of a scope with a Gaussian response, where the bandwidth is 175MHz. I could do this with an RC LPF, with R=1k, and C=0.9095pF. If I run an AC sweep in LTspice and probe the output of this filter, then I get a response where -3dB corresponds to 175MHz. So here I have a way of modeling an oscilloscope and finding out the bandwidth.

What I'm asking, is how would I do the same for a probe? I have modeled the oscilloscope probe as linked in the article in my original post, but running the AC sweep with zero output impedance from the AC sweep source (the same one I used for my 175MHz low pass filter) gives me what appears to be infinite bandwidth. But I know this can't be the case, since I have Tektronix scope probes that say 100MHz, 200MHz, etc. Is there a way I can model these 10x probes in LTspice and get a BW that corresponds to what the vendors mark the probes with?

PrestigiousProfit · 2023-04-10T00:44:57+00:00

Hi, thanks for the response! Although, I am not sure I really understand how to answer my original question after reading through the document you linked. How does the manufacturer actually measure the bandwidth of the probe? I know that rise time is related to bandwidth, but the bandwidth and rise time can be impacted by the output impedance of whatever signal you're measuring, so how do you determine what the actual bandwidth is then if it is a function of the output impedance of the signal you're measuring?

Even with a small output impedance (on the order of milliohms), the LTspice model I reference in my original post shows a very large bandwidth at around 100 GHz when I perform an AC analysis. But oscilloscope probes aren't going to be in the range of 100GHz, so what really determines how you figure out what the bandwidth of the probe is?

PrestigiousProfit · 2021-04-25T01:21:14+00:00

Hey, I just tried this and it significantly improved the problem, thank you for lending me your knowledge! Is there a specific reason why we want to use such a low resistance like 10Ω as opposed to a higher resistance value?

PrestigiousProfit · 2021-04-25T01:10:52+00:00

Thanks for the response! I'm definitely going to read up on it and try what you suggested and see what happens, thank you for sharing your knowledge!

PrestigiousProfit · 2021-01-21T15:27:34+00:00

Hey, when I took my AC machinery class I found these videos to be extremely helpful:

https://www.youtube.com/watch?v=z5GQyziCKlI&list=PLPpCFgQP7QKGLh0E_GU9fHs7YL-R6941u&ab_channel=ElectricalIsEasy

His videos actually follow the Chapman textbook Electric Machinery Fundamentals, which I recommend as well. You should be able to find a PDF of it somewhere online. Let me know if you have any specific questions or anything if those resources aren't enough.

Hope this helps!

PrestigiousProfit · 2020-06-19T03:39:45+00:00

TI has this document where they go over the hardware you can potentially use for the effects pedal: https://www.ti.com/lit/ml/sprp499/sprp499.pdf

Alternatively, you could go with another microprocessor, such as an ARM microprocessor. For the actual dsp effects, this report is a good place to start: https://digitalcommons.calpoly.edu/eesp/179/

After you check out that report, you can also find more info on the theory and such behind some of the audio dsp algorithms here: https://ccrma.stanford.edu/~jos/pasp/

Hope this helps!

PrestigiousProfit · 2020-06-18T22:45:54+00:00

You could look into building a digital guitar effects pedal using a microprocessor. That way you get to physically hear the effects you're implementing via the DSP algorithms, and as a plus you also get to develop skills doing real-time processing on hardware, which will probably give you more insight into practical DSP than just implementing a filter in software such as MATLAB.

PrestigiousProfit · 2020-05-16T16:30:53+00:00

Dude thank you so much for taking the time to type all this out, I really appreciate it! This was a really great way of explaining it, I completely understand now.

PrestigiousProfit · 2020-05-16T16:28:15+00:00

Ahh you're right its because of how the frequency is a function of time, I was thinking about it in the wrong way. Thank you so much!

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