Help determining the equivalent mechanical system for a filter?
Help determining the equivalent mechanical system for a filter?
(OP)
I'm a little rusty on my circuit analysis, so I was hoping someone more well-versed in circuit analysis could give me a little help in figuring out a filter I'm interested in. I believe it is a Butterworth filter.
I'm a mechanical engineer, and it'd be easier to set up the differential equation if I could visualize it mechanically. So, if anyone could help, what would the equivalent mechanical system be for the following filter?
www.wenzel.com/graphics/pinet.gif
I think that it's a dashpot and spring in parallel with a mass (I hope this pastes ok):
----------
---DASHPOT----| |
| mass |
----SPRING------| |
----------
...but I can't figure out where to place the left-most capacitor. Is in in series with the dashpot?
The end result is that I want to model the transient response (using a step-time type integration) for non-linear voltage inputs (square, saw, etc).
Thanks in advance for any help!
Dave
I'm a mechanical engineer, and it'd be easier to set up the differential equation if I could visualize it mechanically. So, if anyone could help, what would the equivalent mechanical system be for the following filter?
www.wenzel.com/graphics/pinet.gif
I think that it's a dashpot and spring in parallel with a mass (I hope this pastes ok):
----------
---DASHPOT----| |
| mass |
----SPRING------| |
----------
...but I can't figure out where to place the left-most capacitor. Is in in series with the dashpot?
The end result is that I want to model the transient response (using a step-time type integration) for non-linear voltage inputs (square, saw, etc).
Thanks in advance for any help!
Dave





RE: Help determining the equivalent mechanical system for a filter?
RE: Help determining the equivalent mechanical system for a filter?
CODE
Fv1 | | Fv2
(fixed) o--@@@@@---+--| M |--+---@@@@@@---o (fixed)
Kc1 | | | Kc2
spring +-----+ | spring -+
| ||
+-----------||----o (fixed)
||
-+
dashpot
Where: electrical param mechanical param
----------------------- ----------------
V1 (voltage) Fv1 (force)
V2 (voltage) Fv2 (force)
Il (inductor current) Vm (mass velocity)
Qc1 (charge on C1) Xc1 (spring displacement)
Qc2 (charge on C2) Xc2 (spring displacement)
To apply V1, apply a force to point Fv1. To measure V2, measure the force
between the mass and Fv2.
RE: Help determining the equivalent mechanical system for a filter?
Thanks again,
Dave
RE: Help determining the equivalent mechanical system for a filter?
However, the pi filter cited has 4 passive components, while the mechanical "equivalent" only has 3.
TTFN
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RE: Help determining the equivalent mechanical system for a filter?