Part 14
Reference
Every element, every answer name, what each tool returns, every setting, and what a saved file remembers. Lookup, not reading.
Last updated 2026-09-11
Elements
name first, then these, comma-separated. Italic fields are optional.
| Element | Fields | Notes | |
|---|---|---|---|
| r | resistor | n1,n2,value | value may be [r,r,…] in parallel |
| l | inductor | n1,n2,value ,i₀ | i₀ read by FD and TR |
| c | capacitor | n1,n2,value ,v₀ | v₀ read by FD and TR |
| e | voltage source | n1,n2,value | dependent if value names an answer |
| j | current source | n1,n2,value | current flows n1 → n2 inside it |
| o | ideal op amp | n+,n−,nout | a nullor; reports i and p, no v |
| m | mutual inductance | Lname1,Lname2,M | names two inductors; no answers |
| s | short circuit | n1,n2 | |
| t | transformer | n1,n2,t1,t2 | or [tl,bl],[tr,br],[t1,t2] |
| z y h g a b | two-port | n1,n2 ,[p11,p12,p21,p22] | or bracketed pairs |
Node 0 is ground. Names are letters, digits and underscores; the first character picks the type.
Answer names
Both spellings work everywhere: ir1 and i_r1, v2 and v_2. Case is ignored.
| Where | ||
|---|---|---|
v<node> | node voltage | all |
i<el> | current, first node → second | all |
v<el> | voltage drop, first minus second | all |
p<el> | power consumed | all |
ap<el> | average power | AC |
s<el> | complex power, P + jQ | AC |
z<el> | impedance seen | AC, FD |
r<el> | resistance seen | DC |
i<el><node> | terminal current | transformers, two-ports |
SI prefixes
Apostrophe, then the letter. Exact, not decimal.
'P 10¹⁵ | 'T 10¹² | 'G 10⁹ | 'M 10⁶ | 'k 'K 10³ | |
'm 10⁻³ | 'u 'µ 10⁻⁶ | 'n 10⁻⁹ | 'p 10⁻¹² | 'f 10⁻¹⁵ | 'a 10⁻¹⁸ |
Case matters everywhere but kilo. 8000 and 8'k are exact; 8000. and 8E3 are approximate.
Analyses
| DC | steady state | ignores initial conditions |
| AC | one ω, phasors | needs an ω |
| FD | s-domain | initial conditions included |
| TR | time domain | answers in t, valid for t ≥ 0 |
Tools and mini-tools
| Tool | Takes | Returns |
|---|---|---|
| Resistance / impedance | two nodes | req or zeq |
| Thévenin / Norton | two nodes | vth, ino, req, pmax |
| …with the load tick | plus irl, vrl, prl | |
| Two-port parameters | two nodes, a kind | four parameters of that kind |
| pf | complex power or impedance | power factor, with lead/lag |
| gain | parameters and a load | Gᵥ, Gᵢ, Gₚ, Zᵢₙ |
| aa | a complex value | amplitude and angle |
Plots
| Analysis | |
|---|---|
| Plot a function of time | TR |
| Bode plot of a variable | FD |
| Bode plot of transfer function H(s) | none needed |
| Plot a variable against another | DC |
Settings
| Changes | |
|---|---|
| Rounding — exact / exact+approx / approx to n / approx full | the display |
| Show units | the display |
| Use SI prefixes in answers | the display; forces off exact |
| Show AC answers as polar phasors | the display; AC only |
| Show equations | adds the Equations card |
| RMS phasors | the answer. AC only |
Full detail in “Settings”.
What a saved file remembers
A .cir entry carries 32 fields: the description, the analysis and its settings, Define, Evaluate and its conditions, Solve, Expert Mode's three boxes, the plot's five, the display settings, a note and an image. Saving and reloading returns you to the run, not just the circuit. Working with input files has the format.
Outside the tool
Fourier series and transforms · convolution · energy · nonlinear devices · transmission lines · noise and tolerance analysis.
Supported but not automated, because each is something you do to the circuit and then solve: superposition · source transformation · power-factor correction · pole-zero work · magnitude and frequency scaling.