Introduction / Context:
Reference designations (like R5, C12, U3) enable manufacturing, testing, and field service to locate and replace components unambiguously. The statement asserts that identification is typically unnecessary; we test this claim against accepted documentation practices.
Given Data / Assumptions:
- Diagram supports procurement, assembly, and maintenance.
- Bill of materials cross-references reference designations.
- Technicians rely on designators to troubleshoot.
Concept / Approach:
Each replaceable part on a schematic should carry a unique reference designation tied to a BOM entry (part number, value, tolerance, footprint). Without it, assembly automation and service documentation become error-prone, increasing cost and downtime.
Step-by-Step Solution:
Assign unique designators per component class (R, C, L, D, Q, U, J, etc.).Link designators to BOM line items including value and footprint.Place designators legibly near symbols with adequate whitespace.Include notes for orientation, polarity, or pin-1 markers as needed.
Verification / Alternative check:
Attempt to order and assemble the product using the schematic and BOM; if every replaceable item is traceable, documentation is adequate.
Why Other Options Are Wrong:
Correct: The claim is false; identification is necessary.Required only on assembly drawings / Needed only for ICs: All replaceable items, including passives and connectors, need designators.
Common Pitfalls:
Tiny, overlapping designators that are unreadable after printing.Mismatches between schematic designators and PCB silkscreen.
Final Answer:
Incorrect
Discussion & Comments