Source: https://guthlabs.ai/docs/instruments/rc-rl-time-constant-transient-solver/implementation/

instrument implementation / implementation-contract

# RC/RL Time Constant & Transient Solver implementation

A source-bound implementation contract for RC/RL Time Constant & Transient Solver; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t2-030

**Effect**: Computation or source lookup only

## Input and validation requirements

The solver has an undefined exact-input case at R = 0 because τ = RC = 0 and the exponential requires division by τ. It also lacks an explicit transient-mode or initial-condition input, so it cannot reliably distinguish charging from discharging behavior; signed-voltage convention is likewise unspecified.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "circuit": "RC charge",
    "R": 1000,
    "R_unit": "ohm",
    "C": 0.000001,
    "C_unit": "F",
    "V": 5,
    "V_unit": "V",
    "t": 0.001,
    "t_unit": "s"
  },
  "expected_outputs": {
    "tau": 0.001,
    "tau_unit": "s",
    "v_t": 3.160602794,
    "v_t_unit": "V",
    "percent_charged": 63.21205588
  },
  "working": "τ=RC=1000×0.000001=0.001 s. t/τ=0.001/0.001=1. v(t)=5(1−e^(−1))=5(1−0.3678794412)=5×0.6321205588=3.160602794 V. Percent charged=100×0.6321205588=63.21205588%."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/rc-rl-time-constant-transient-solver/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/rc-rl-time-constant-transient-solver/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/rc-rl-time-constant-transient-solver/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche2/tranche2-results.json`