While reminding myself of what Python's scipy.signal library can do for filter design I found a reference to a tool called Elsie that does passive filter network design stuff, might be interesting to try out: http://www.tonnesoftware.com/elsie.html - note I've not tried it and the student version is limited to 7 circuit elements, full commercial version handles upto 41.
Electronic Filter Design Handbook, 1981, 782 pages, 22MB PDF download.
ELECTRONIC FILTER DESIGN HANDBOOK https://d1.amobbs.com/bbs_upload782111/files_32/ourdev_573166.pdf
I also recall using the CRC Handbook of Electrical Filters.
ELECTRONIC FILTER DESIGN HANDBOOK https://d1.amobbs.com/bbs_upload782111/files_32/ourdev_573166.pdf
I also recall using the CRC Handbook of Electrical Filters.
Ladder filter?
Basic voltage controlled lowpass filter for synthesis?
Dont get it, its a active filter using feedback , there is no passive equivalent
If there was, a basic spice model would give you the outcome.
Agree for audio applications there is no point, and would be done active regardless.
Otherwise its been emulated countless times in software.
But a software model is pointless for a passive application.
Just a discrete transistor design that looked liked a ladder
in the schematic. Otherwise plain jane 2 pole or 4 pole lowpass filter
with adjustable cutoff and resonance / Q
Basic voltage controlled lowpass filter for synthesis?
Dont get it, its a active filter using feedback , there is no passive equivalent
If there was, a basic spice model would give you the outcome.
Agree for audio applications there is no point, and would be done active regardless.
Otherwise its been emulated countless times in software.
But a software model is pointless for a passive application.
Just a discrete transistor design that looked liked a ladder
in the schematic. Otherwise plain jane 2 pole or 4 pole lowpass filter
with adjustable cutoff and resonance / Q
Why would a model of a filter network be pointless? That’s the best way to develop them.
I have used a very high order passive filter to block Class D amp carrier frequencies above 100kHz with a passive “brick wall” filter (circa -95dB/Oct) This one was developed by member Aridace and I built it and it works very well.
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Based on the information in post #16 and the unity DC gain, the transfer function can be nothing but:
H(s) = (s2LC1 + 1)/(s2L(C1 + C2) + s (L/R) + 1) =
(C1/(C1 + C2)) * (s2+ 1/(LC1))/(s2 + s * 1/(R(C1 + C2)) + 1/(L(C1 + C2)))
That's the one patented by Bob Moog, and famous for being on tattoos and such. I also thought of that particular circuit, but here I understood ladder filter to be a more general term for a filter whose schematic can be drawn in the form of a ladder.