What Symbulator is

Symbulator solves linear electric circuits symbolically. You describe the circuit as text, choose an analysis, and get every current, voltage and power in it — as exact expressions, not decimals, unless you ask otherwise.

It is not SPICE. There is no netlist to compile, no convergence to tune, no timestep. A circuit is a handful of lines, and the answer comes back as algebra you can read.

What it solves

Four analyses, on the same description:

Fifteen element types, listed in The circuit description. Three tools that answer a question about a circuit rather than solving it outright — equivalent resistance, Thévenin/Norton and two-port parameters — and three mini-tools that work on values you type: aa, pf and gain.

Every value may be a symbol. That is the point of the thing: leave r1 as r1 and the answer comes back in terms of r1.

What it will not do

Linear circuits only, lumped elements only. Nine topics from a first course in circuits fall outside it, and it is cheaper to say so here than to have you hunt:

• Fourier series and transforms. Not implemented.
• Convolution. Not implemented.
• Energy. You get power; integrating it is yours.
• Nonlinear devices. No diode curve, no transistor model. A transistor enters as its small-signal equivalent, which is linear, and works.
• Transmission lines, and anything distributed.
• Noise, tolerance, Monte Carlo. Not a statistical simulator.

Four more are supported but not automated — superposition, source transformation, power-factor correction and pole-zero work. Each is a thing you do to the circuit, then solve. No tool does it for you.

Where it runs

Three builds of one interface, and they behave identically:

The solver is also a Python package: pip install symbulator.