Public evidence

electrical.lpf

Machine-checked verification for calculation version 1.0.0 · tier expert_verified

Open calculator API Capability Download JSON CVP Manifest MCP Review policy

CVP: CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance· First-order RC LPF only · Protocol · Schema · Production report

Declared partition coverage: PASS · 4/4 declared partitions (solve-rc, with-f, solve-C, invalid-domain)
Versions: Calculation 1.0.0 · CVP protocol 1.0.0-proposed
CVP identity: 4/4 property · digest 00b0f7286660

Verification

Legacy regression suite: 10/10 calculation tests · Production surface contract 3/3

Three distinct suites: educational examples on the calculator page, this legacy regression count (10/10 golden + boundary), and the CVP verification suite below. They are not the same number. Property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the CVP Manifest . SKIP (0/0) means that suite has no published vectors.

This calculator CURRENT · Public schema 1.0.0 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

CVP verification suite

Protocol checks from the Evidence Manifest. Distinct from the legacy regression suite above. Calculation version 1.0.0. CVP 1.0.0-proposed. 3/3 golden · 3/3 CVP boundary · 3/3 invalid · 4/4 property · 1/1 cross-interface · 1/1 CVP contract. digest 00b0f7286660.

Golden (oracle-backed) 3 / 3
CVP boundary 3 / 3
Invalid input 3 / 3
Property 4 / 4
Cross-interface 1 / 1
CVP contract 1 / 1
Interfaces PASS · UI (SSR) / REST / MCP
Interface claim ui-ssr is query-result HTML, not a live browser session.
Assurance Engineering

release artifacts aligned PASS
schema valid input executes PASS
engine success output validates schema PASS

Fingerprint sha256:ea861dc7b537c417718182fdd4aa315b2e06af83b487639bbebdde4f000ef54d

Input schema sha256:3ea9dcf4d535ac29b41a21e58a64dbc11f409315913a92db011a8e8d109600e1 · Output schema sha256:f5197a7821076ed820bfe25c3093c4d8c1a326cca1b61b661761d67d4b6c570c · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Build & scope

Engine identity and declared limitations.

Tool: lpf
Engine: lpf
Engine build: 2026-09-10
Evidence core: 2026-09-05T02:35:39.217Z
Rendered: 2026-09-16T22:03:43.716Z
Last reviewed: 2026-08-08

Assumptions

Ideal lumped series-R / shunt-C LPF.
When R and C are both given, fc is recomputed from them.

Limitations

First-order passive RC LPF only
Fewer than two of R/C/fc → NEEDS_TWO_INPUTS
When R and C both provided, fc is recomputed

Sources

Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.

Horowitz & Hill — The Art of Electronics — Single-pole RC filters
Supports: fc = 1/(2πRC); −3 dB at corner; −20 dB/decade
IEC 60050 — IEV — Cut-off frequency
Supports: Definition of cutoff / corner frequency for filters

Legacy published checks

Golden and boundary cases from the legacy Evidence JSON. CVP property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the Manifest — including SKIP when a suite has no vectors.

ID	Kind	Status	Detail
`rc-fc`	golden	pass	Expected fc=15.915494309189533 · tau=0.01 · Actual R=10000 · C=0.000001 · fc=15.915494309189533 · tau=0.01 · omega_c=100
`mag-at-fc`	golden	pass	Expected H_dB=-3.0102999566398125 · Actual R=10000 · C=0.000001 · fc=15.915494309189533 · tau=0.01 · omega_c=100 · f=15.915494309189533 · H_lin=0.7071067811865475 · H_dB=-3.0102999566398125
`solve-C`	golden	pass	Expected C=3.386275384933943e-8 · Actual R=4700 · C=3.386275384933943e-8 · fc=1000 · tau=0.00015915494309189532 · omega_c=6283.185307179586
`needs-two`	boundary	pass	Expected NEEDS_TWO_INPUTS · Actual NEEDS_TWO_INPUTS
`zero-R`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`nan-C`	boundary	pass	Expected INVALID_NUMBER · Actual INVALID_NUMBER
`property-fc`	property	pass	fc from RC
`property-3db`	property	pass	−3 dB at fc
`property-solve-C`	property	pass	C from R,fc
`property-half-fc`	property	pass	2R → ½fc