How to Draw a Bode Plot Without a School Book

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Homework Help Overview

The discussion revolves around drawing a Bode plot for the transfer function H(S) = s + 10. The original poster seeks guidance on how to create this plot without access to a textbook.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the necessity of understanding asymptotes and the implications of having no poles or zeros. Questions arise about the interpretation of the transfer function and the significance of the variable 's' in relation to frequency response.

Discussion Status

Some participants have provided links to external resources and tutorials, while others clarify concepts related to the transfer function and its components. There is an ongoing exploration of the implications of the original poster's equation and the context of frequency response.

Contextual Notes

The original poster expresses difficulty in understanding the provided resources, particularly regarding the notation involving 'jω'. There is also a mention of the potential misplacement of the thread in the forum categories.

cleopatra
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Homework Statement



How do you draw a bode plot?
I have a simple equation: H(S)=s+10 but no school book. Can you teach me?
 
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How about a tutorial?
http://www.facstaff.bucknell.edu/mastascu/elessonsHTML/Freq/Freq5.html

When you're drawing by hand, usually only the asymptotes are required; the effects of zeros, poles, higher ordered zeros and poles, and most of the simple cases are usually tabulated in the first chapter of any controls textbook.

EDIT: Summary for drawing asymptotic transfer functions (agrees with what I remember):
http://en.wikipedia.org/wiki/Bode_plot#Rules_for_hand-made_Bode_plot

EDIT: This post might've been better in the EE or Engineering homework subforum.

EDIT: Thought I recognized the username... Since you asked a MATLAB question, you may also want to look in this thread:
https://www.physicsforums.com/showthread.php?t=303967
 
Last edited:
I don´t have any poles and no zeros either.
So what do I do then? Or do I have one zero? = -10 ?

But I really don´t understand those webpages because they all have jw sth..
 
Yes, there's one zero. I'm not sure how far along you are in your complex math or controls course, but s is the 'generic' frequency [tex]s=\sigma+j\omega[/tex]. If you're finding the frequency response (as you are in a Bode plot) you're only concerned with the situation where [tex]\sigma[/tex] is zero and frequency is imaginary (i.e. sinusoidal). That's why some of the previously-linked resources use [tex]j\omega[/tex] instead of s (even though the transfer function is given in terms of s)

Put another way, if your transfer function is called H(s), you're finding |H(jw)| (the magnitude of the frequency response) and the phase
 

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