functional-block-reconstruction

name	functional_block_reconstruction
description	Use when: Reconstructing circuit functional blocks, power paths, signal flows, and circuit topology from identified components and PCB traces. Maps components to circuit functions. Funktionsblöcke, Strompfad, Schaltungsrekonstruktion, Topologie, Leiterbahn-Analyse, Blockschaltbild, power path.

<skill_purpose> Derives the probable functional architecture of a circuit from component positions, package types, markings, and visible PCB traces. Produces a structured block model that guides fault hypothesis generation. </skill_purpose>

- Component inventory (from `board_image_intake` or equivalent) - Visual observations (board images or observation notes) - Optional: Known symptom or failure mode for focused path analysis 1. Identify the primary power supply path (positive terminal → load → ground return). 2. Derive the charge path if applicable (charging port → protection circuit → cell). 3. Reconstruct switch and button signal paths and their effect on load or motor. 4. Map transistors, diodes, and protection components to their functional role in each block. 5. Identify critical nodes where an unexpected voltage drop could explain the symptom. 6. Flag any IC that may implement multiple functions (e.g., combined charge + protection controller).

<output_format> Create or update analysis/03_functional_blocks.md (or the path specified by the user) with this structure:

Observed Topology [General circuit architecture, e.g., "Single-cell Li-Ion with discrete motor driver and integrated charge controller"]

Functional Blocks

Block	Components	Function	Evidence	Confidence
Power Input	J1, F1	Battery connection + overcurrent protection	[Image: 2-pin edge connector, axial component]	High
Charge Control	U1 (TP4056)	CC/CV Li-Ion charging via Micro-USB	[Image: marking] + [Research: TP4056 datasheet]	High
Load Switch	Q1 (S8050)	Motor enable/disable via SW1	[Image: NPN package near motor pads]	Medium
User Input	SW1	Power on/off	[Image: tactile switch, top-side]	High

Probable Current Path [Trace logical flow: e.g., Battery(+) → J1 → F1 → U1(BAT) → Motor → Q1(collector) → GND]

Critical Nodes [List test points with highest diagnostic value, e.g., "J1 input vs. U1 BAT pin under load"]

Open Uncertainties [Functional blocks that cannot be determined from available evidence — state why] </output_format>

- Derive component functions only from visible evidence, plausible datasheet applications, and valid electronics engineering knowledge. - Mark uncertain signal paths as hypothetical — never assert circuit topology as fact when internal traces are not visible. - Annotate each functional block assignment with its evidence source: [Image], [Research], [Domain Knowledge]. - When a trace cannot be followed (hidden layer, solder mask), state this explicitly rather than assuming connectivity.