Asymptotic Bode Plot Issue in Mathcad Prime 7

Forum|Forum|3 years ago
November 17, 2022
1 reply
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Obtaining the ASYMPTOTIC Bode plot for the following transfer function:

Mathcad Prime 7 result:

Why does the result in the Mathcad Prime 7 not look like it looks like in the figure in the example??
The idea is that I want the plot in Mathcad Prime 7 to look exactly like in the picture above, with straight lines and those corners, and not to bend corners Mathcad Prime 7 at w=2 and w=10.

Mathcad Prime 7 file attached.

1_Untitled-3_Mathcad_Prime7.zip

Best answer by Werner_E

To get the asymptotic approximations you simply have to replace in expressions like 1+j w the 1 for a zero (aka omit it).
For w -> infinity these 1's are neglectable.

Maybe this link additionally helps to understand: https://lpsa.swarthmore.edu/Bode/BodeHow.html

W

Werner_E

Answer

25-Diamond I

To get the asymptotic approximations you simply have to replace in expressions like 1+j w the 1 for a zero (aka omit it).
For w -> infinity these 1's are neglectable.

Maybe this link additionally helps to understand: https://lpsa.swarthmore.edu/Bode/BodeHow.html

C

Cornel

Author

19-Tanzanite

Mathcad 15 result:

Mathcad Prime 7 result:

At w = 10, let's say it's something more ok (even if it's not even right angle there at the intersection (as it kind looks like in Mathcad 15)), but at w = 2 why is not ok (only somewhere at w=~ 2.1 seems to be more ok/accurate)?

The same results, no matter where I put the greater than or equal sign (so that it also contains the end values w=2 and w=10):