Skip the settling.
The periodic switching-period orbit is solved for directly, so you read ripple off a converged result instead of a transient that is still drifting when it looks flat.
Switch-mode power electronics
Change a switching converter. See the next result.
PWMSim is a browser simulator for the practical engineering loop: edit a circuit, run a transient or periodic steady state, inspect the waveforms, measure the result, and sweep the parameters that matter.
No install and no sign-up. The solver is compiled to WebAssembly and runs on your machine.
Free, no accountNo sign-up, no run counts, no element caps,
no time-boxed sessions.
Circuits stay putYour circuit never leaves the browser. Not
on any tier, paid or free.
Portable workSave locally and export project JSON, portable
netlists, schematic images and evidence reports.
Built around converter work
Each of these is a thing a general transient makes you work around. Every claim below has files behind it on the benchmark page.
Measure, do not eyeball.
Probe voltages and currents, add expressions, use cursors and saved metrics, and inspect the spectrum over the interval you actually selected.
Compare design points.
Sweep a component property over explicit values. Every point reports its own result or failure instead of disappearing from the curve.
The part worth reviewing is the evidence
Every benchmark case ships the portable netlist, the measurement recipe and the tolerance, so you can open the same file in LTspice and check the row yourself. No comparison is published without the file, version, measurement recipe and tolerance beside it.
6
portable cases, each a netlist you can download and rerun
38/38
same-file LTspice parity measures passing, boundary stated per row
0
cookies, accounts or circuit-content fields in product telemetry
What it does not do yet
Unsupported constructs are reported, not silently approximated. The boundary is part of the product.
- ImportArbitrary LTspice behavioural decks are not guaranteed; import reports what mapped exactly, what was approximated and what is unsupported.
- MotorsThe abc↔dq motor-drive interface is present but not promoted.
- PFCPortable line-cycle controller behaviour is a real capability gap, not a documentation gap.
- ConvergenceNo "SPICE could not converge on this" page is published, because no qualifying real case has been collected.
Try a real buck in about two minutes
Open the recommended buck, change its switch duty, run it again, probe the output and read the ripple between two cursors. Save the project locally or export it when you are done.
Thinking about repeatable
checks, batch runs or CI? Those are directions under consideration,
not shipped features. Tell us about your workflow
if that would remove a real engineering constraint.