Source: https://guthlabs.ai/docs/instrument-workflows/power-rail/

instrument chain / verified-workflow-definition

# Electronics Power-Rail Designer

From supply to a cool-running, properly-routed rail.

Status: **observed**Lifecycle: **verified-workflow-definition**

## Goal

From supply to a cool-running, properly-routed rail.

## Instrument chain

- 01

**[Voltage/Current Divider](<https://guthlabs.ai/docs/instruments/voltage-current-divider/>)**

sense/scale

VERIFIED

- 02

**[Voltage Regulator (Linear) Resistor/Output Calculator](<https://guthlabs.ai/docs/instruments/voltage-regulator-linear-resistor-output-calculator/>)**

set Vout

VERIFIED

- 03

**[Linear Regulator Power Dissipation & Heatsink Need](<https://guthlabs.ai/docs/instruments/linear-regulator-power-dissipation-heatsink-need/>)**

dissipation

VERIFIED

- 04

**[Heat Sink Thermal Resistance Calculator](<https://guthlabs.ai/docs/instruments/heat-sink-thermal-resistance-calculator/>)**

thermal chain

VERIFIED

- 05

**[LED Series Resistor Calculator](<https://guthlabs.ai/docs/instruments/led-series-resistor-calculator/>)**

indicators

VERIFIED

- 06

**[PCB Trace Width Calculator (IPC-2221)](<https://guthlabs.ai/docs/instruments/pcb-trace-width-calculator-ipc-2221/>)**

copper for current

VERIFIED

- 07

**[PCB Trace Resistance & Voltage Drop](<https://guthlabs.ai/docs/instruments/pcb-trace-resistance-voltage-drop/>)**

IR drop

VERIFIED

- 08

**[PCB Via Current Capacity Calculator](<https://guthlabs.ai/docs/instruments/pcb-via-current-capacity-calculator/>)**

vias

VERIFIED

- 09

**[Series/Parallel Resistor Combiner](<https://guthlabs.ai/docs/instruments/series-parallel-resistor-combiner/>)**

networks

VERIFIED

## Handoffs and cross-checks

Vin−Vout×I → Pd → θ chain → Tj; rail current → trace width → IR drop.

## PointGuard stance

Close the thermal loop every time: Tj from Ta+Pd·Σθ must clear Tj_max with stated margin before the design is "done".

## Sources and evidence

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

- `INSTRUMENT_COMBOS.json`

- `VERIFIED_LEDGER.json`