Elsie the filter program

The Windows ® program for electrical filter design and analysis

Current revision is 2.84; revision history is at the bottom of this page

Elsie™ is an uncommon commercial-grade lumped-element ("L-C") electrical filter design and network analysis program, directed toward the engineer, technician or hobbyist involved in that line of work.

Here are screen dumps from the program illustrating some of the outputs to the screen. Click on them to see larger versions; use your browser's BACK button to return.

Design menu
Design menu

Analysis menu
Analysis menu

Plot showing transmission and return
Plot S21 & S11

Transmission with limits
S21 with limits

Transmission with limits and markers
S21, limits, markers

Transmission and delay
S21, delay

Normal Smith Chart
Smith Chart

Magnified Smith Chart
Smith 2x, markers

Illustrating a tuning mode
Tuning mode

A tone-burst
Tone burst

Envelope of tone-burst
Envelope of burst

How schematic is presented on-screen

Circuit editor screen
Circuit editor

Tabulated output
Tabulated output

Normalized value display
Normalized values

Monte Carlo while running
Monte Carlo running

Monte Carlo stopped
Monte Carlo stopped

Modulation response of a bandpass
Modulation response

Inductor specification
Inductor specs

Overlay example - various orders
Saving overlays

Tuning passband ripple
Tuning passband ripple

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Updated to 2.84 - Found and corrected oddity in circuit editor
Updated to 2.83 - Show stage resonant frequency while tuning L-C elements
Updated to 2.82 - Found and corrected error on manual-entry page (shunt RLC element)
Updated to 2.81 - Significant upgrades; records unfortunately lost
Updated to 2.77 - Significant upgrade of unbalanced/balanced schematic; log scale on circular S21 display
Updated to 2.76 - Corrected yet another Cauer error trap
Updated to 2.75 - Added 'Tune Apass' button on plot screen
Updated to 2.74 - Corrected oddity in M-Derived highpass data entry
Updated to 2.73 - Total rewrite of Cauer error trapping
Updated to 2.72 - Refined Design screen error trapping
Updated to 2.71 - Found and corrected error in Monte Carlo stepsize assignment
Updated to 2.70 - Complete rewrite of .CIR and .SUB file writers
Updated to 2.69 - Added SPICE subcircuit file writer and LTspice filter symbol (.ASY) writer
Updated to 2.68 - Added generic SPICE file (.CIR) writer
Updated to 2.67 - Force LTspice .ASC files to have periods for decimal places; cosmetic and minor interface upgrades
Updated to 2.66 - Increased plot X-axis divisions to 20; allowed negative jX values in editor
Updated to 2.65 - Added AutoScale button to plot and analysis pages; allowed diplexer design to go to 10 GHz
Updated to 2.64 - Corrected missing element in Manual Entry routine
Updated to 2.63 - Total rewrite and upgrade of diplexer routine
Updated to 2.62 - Found and corrected errors in page/screen sizes
Updated to 2.61 - Found and corrected error in file reader; updated editor, file writing and file reading
Updated to 2.60 - Added schematic display option to show the filter as it would be in a balanced configuration; improved erroneous-value entry handling in circuit editor
Updated to 2.59 - Clarified Cauer odd/even entry areas; polished design and editor pages
Updated to 2.58 - Added capability to change return loss reference value to editor page
Updated to 2.57 - Found and corrected error in transmission line math routine when line lengths are exactly 90 degrees; limited S11 and S21 to -120 dB
Updated to 2.56 - Found and corrected S11 and S22 phase error in Touchstone file writers (Versions 1 and 2)
Updated to 2.55 - Added bandpass filter modulation-response routine
Updated to 2.54 - Complete rewrite of transient-response routine
Updated to 2.53 - Added Entry Assistance screen; revision of Analysis screen
Updated to 2.52 - Found and corrected error in Cauer highpass design routine; other cosmetic upgrades
Updated to 2.51 - Complete rewrite of Wind Inductor routine
Updated to 2.50 - Rewrite of all subroutines for uniform appearance; limits-editing bugfix; many cosmetic upgrades
Updated to 2.49 - Complete rewrite of circuit editor and manual component-entry routines along with upgrades to schematic display and design inputs
Updated to 2.48 - Complete rewrite/update of inductor-specification routine
Updated to 2.47 - Upgraded plotting screens to show on the screen the point where the mouse-down datapoints are being taken; Smith Chart seriously upgraded
Updated to 2.46 - Upgraded Design page to prohibit problems resulting from missing bandpass/bandstop center frequency, or missing topology entry
Updated to 2.45 - Corrected file-reading and file-writing routines to ignore unused numbers in memory; corrected Cauer normalized-value readout
Updated to 2.44 - Upgrade normalized-value routine; added option to send normalized values to printer
Updated to 2.43 - Major upgrades to each of the routines on the Design page
Updated to 2.42 - Major upgrade to Smith Chart routine
Updated to 2.41 - Major upgrade to Monte Carlo routine
Updated to 2.40 - Changed overlay color scheme
Updated to 2.39 - Corrected erroneous saving of limits areas to file
Updated to 2.38 - Corrected error causing plot type to change unexpectedly
Updated to 2.37 - Corrected error in "specify inductor" routine
Updated to 2.36 - Major revision of Manual Component Entry and Editor pages, revised menu system, added aspect-ratio correction capability
Updated to 2.35 - Added toroidal-inductor turns calculator, Smith Chart aspect ratio correction capability and total re-write of menus
Updated to 2.34 - Refined LTspice file-writer
Updated to 2.33 - Changed order-entry to up/down button style; forced location of Last Session file
Updated to 2.32 - Discovered and corrected error in frequency printout for regions using comma for decimal
Updated to 2.31 - Added "Instant Help" button to the Design page to assist in Family selection
Updated to 2.30 - Added "Instant Help" buttons to the Design page to assist in Topology selection
Updated to 2.29 - Updated Help system
Updated to 2.28 - Added end-sections option to Constant-k family (this in addition to the M-derived family); updated Help system
Updated to 2.27 - Editor now disallows termination or resistor-value entries less than .01 ohms
Updated to 2.26 - Correct various plot top definition entry oddities
Updated to 2.25 - Add option to show "magnified" plot on Transmission graph to reveal detail in low-loss region.
Updated to 2.24 - Changes to design page to prevent design of families requiring passband ripple when no such entry is present.
Updated to 2.23 - Add M-derived family with up to five specifiable zeros; update Help system.
Updated to 2.22 - Eliminate ProLite option; miscellaneous upgrades.
Updated to 2.21 - Rewrite of bandpass impedance-matching routine.
Updated to 2.20 - Add nominal-value plot(s) at end of Monte Carlo routine. Also allow overlays to be placed on top of Monte Carlo display.
Updated to 2.19 - Remove revision number checking, fix tuning mode error.
Updated to 2.18 - Added resistors to those elements used for the Optimization and Monte Carlo routines.
Updated to 2.17 - Added LTspice schematic-writing
Note: Tonne Software has no connection with Linear Technology Corp.
Updated to 2.16 - Total rewrite and expansion of bandpass Impedance Matching routine and associated Help system
Updated to 2.15 - Added tabulated-data file writing
Updated to 2.14 - Correct conditional errors for Optimizer maximum-allowed-time and limit-deletion
Updated to 2.13 - Correct subtle plot-color error in Monte Carlo and Optimizer routines; upgrade Exit message
Updated to 2.12 - Total rewrite of Diplexer routines and associated Help system; minor cosmetic text-size changes
Updated to 2.11 - Rewrite of Monte Carlo and Optimization routines; notice design changes and suggest saving prior to retrieving a new design; upgrade Help system.
Updated to 2.10 - Rewrite overlay plotting including simple deletion of overlay files; print all overlay files on hardcopy outputs (to duplicate screen); upgrade Help system.
Updated to 2.09 - Correct error in coupled-inductor component in the optimization routine; minor interface improvements.
Updated to 2.08 - Near-total rewrite of Plot page menu and Help graphics.
Updated to 2.07 - Printing problem resolved; nearly complete rewrite of menu and help system.
Updated to 2.06 - Cosmetic only; most text size as well as graphics now independent of screen resolution.
Updated to 2.05 - Add another error-trap to Cauer design.
Updated to 2.04 - Add error-trap to Cauer design.
Updated to 2.03 - All outputs to printer are now routed via Printer Selection windows.
Updated to 2.02 - Save-file (an internal operation) now forces use of a period for decimal delineation to allow operation in global regions which use a comma for decimal
Released as 2.01 - June 2004