circuit

Declared circuit boundary

Record the intended electrical role, identity level and terminals through which the circuit interacts with its surroundings.

1. What electrical function identifies this circuit, and does the record describe a kind, a design or a physical implementation? definition
2. Which supply, signal, load and reference terminals define its boundary, and which connected subsystems remain outside it? boundary

Verified connectivity

Distinguish intended topology from observed wiring, including switch-dependent connections and return paths.

1. Which components and terminals share each node, and how do switch or control states change the available current paths? definition
2. Which schematic revision, netlist or physical inspection supports the recorded connectivity and return paths? provenance

Supply compatibility

Record each supply domain's accepted electrical conditions and distinguish circuit return, chassis and protective earth where present.

1. What voltage range, polarity, waveform, frequency and source-current capability does each supply input require? measurement
2. Which returns or grounds are connected, isolated or externally established, and where are those relationships documented? boundary

Port loading and levels

Record port-specific levels, impedances, timing and loading assumptions where applicable.

1. What signal ranges, input and output impedances, bandwidths or timing limits apply at each relevant port? measurement
2. Which load types and connection sequences are permitted, and what evidence supports those limits? action

Expected response

Express the circuit's intended response using suitable quantities, such as gain, regulation, switching behaviour or logical state.

1. Which input-output relationship establishes successful operation for this circuit's declared role? definition
2. Under what supply, load, frequency and temperature conditions were the expected response and tolerances established? measurement

State-dependent response

Record transient behaviour, mode transitions and residual energy separately from steady-state performance.

1. What startup, shutdown, switching or protection transitions occur, and what transient voltages, currents or delays characterise them? measurement
2. Which elements may retain energy after supply removal, and what verified procedure establishes the condition required for access? action

Electrical and thermal limits

Record limits with their source, duration and conditions rather than treating component ratings as proof of whole-circuit capability.

1. What continuous and transient voltage, current, power and temperature limits constrain the assembled circuit? measurement
2. Which design calculations, component specifications, tests or applicable standards establish those limits for the intended application? provenance

Fault containment

Record relevant open paths, shorts, leakage, overstress and component degradation alongside any detection or protective provisions.

1. Which observable signatures distinguish an unintended open path, short, leakage path or degraded component from an intended inactive state? definition
2. For each documented fault, what protection acts, what remains energised, and what conditions permit reset or re-energisation? action

Interpretable circuit tests

Associate each observation with circuit state, test location, reference and instrument characteristics.

1. At which nodes or branches should voltage, current, continuity or waveform measurements be taken, and in what circuit state? measurement
2. What probe loading, grounding, isolation, bandwidth and rating constraints must be satisfied for the proposed measurement? action

Electrically valid interventions

Record allowable interventions and the evidence required to confirm restored or revised circuit behaviour.

1. Which component properties, connection details and layout-dependent effects must an intended replacement or modification preserve? action
2. Which updated design records and post-intervention measurements establish the resulting configuration and its acceptable operation? provenance

Check these first

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these check these first hold for the sense of circuit this model covers, and on what evidence? provenance

Kinds and varieties

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these kinds and varieties hold for the sense of circuit this model covers, and on what evidence? provenance

Identifiers and schemes

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these identifiers and schemes hold for the sense of circuit this model covers, and on what evidence? provenance

Standards and regulation

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these standards and regulation hold for the sense of circuit this model covers, and on what evidence? provenance

Real-world use

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these real-world use hold for the sense of circuit this model covers, and on what evidence? provenance

Failure modes and hazards

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these failure modes and hazards hold for the sense of circuit this model covers, and on what evidence? provenance

Regional variation

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these regional variation hold for the sense of circuit this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of circuit this model covers, and on what evidence? provenance