Source: https://guthlabs.ai/docs/instruments/linear-regulator-power-dissipation-heatsink-need/implementation/

instrument implementation / implementation-contract

# Linear Regulator Power Dissipation & Heatsink Need implementation

A source-bound implementation contract for Linear Regulator Power Dissipation & Heatsink Need; 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**: t4-279

**Effect**: Computation or source lookup only

## Input and validation requirements

Extreme finite inputs overflow to Infinity, and the specification lacks ambient-temperature and maximum-junction-temperature limits needed for a definitive heatsink recommendation. Reverse-polarity/sign handling is also 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": {
    "Vin_V": 12,
    "Vout_V": 5,
    "Iout_A": 0.5,
    "thetaJA_C_per_W": 50
  },
  "expected_outputs": {
    "Pd_W": 3.5,
    "junction_temp_rise_C": 175,
    "heatsink_recommendation": "Undetermined from the supplied formulas; requires ambient temperature and maximum junction temperature"
  },
  "working": "Voltage drop = 12−5 = 7 V. Pd = 7×0.5 = 3.5 W. Junction rise = 3.5×50 = 175 °C. A heatsink recommendation cannot be computed without T_A, T_J(max), and a defined decision threshold."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/linear-regulator-power-dissipation-heatsink-need/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/linear-regulator-power-dissipation-heatsink-need/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/linear-regulator-power-dissipation-heatsink-need/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-tranche4/tranche4-results.json`