Lib-electronic-components similarity-resistor

Use when working with resistor similarity calculations - comparing resistor MPNs, understanding value/tolerance/package matching, or implementing resistor-specific similarity logic.

install

source · Clone the upstream repo

git clone https://github.com/Cantara/lib-electronic-components

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/Cantara/lib-electronic-components "$T" && mkdir -p ~/.claude/skills && cp -r "$T/.claude/skills/similarity-resistor" ~/.claude/skills/cantara-lib-electronic-components-similarity-resistor && rm -rf "$T"

manifest: .claude/skills/similarity-resistor/SKILL.md

source content

Resistor Similarity Calculator Skill

Guidance for working with

ResistorSimilarityCalculator

in the lib-electronic-components library.

For metadata-driven similarity architecture, see

/similarity-metadata

SpecImportance levels (CRITICAL, HIGH, MEDIUM, LOW, OPTIONAL)
ToleranceRule types (exactMatch, percentageTolerance, minimumRequired, etc.)
SimilarityProfile contexts (DESIGN_PHASE, REPLACEMENT, COST_OPTIMIZATION, etc.)
Calculator integration patterns and gotchas

Overview

The

ResistorSimilarityCalculator

compares resistors based on:

Package size (0.3 weight) - 0402, 0603, 0805, etc.
Resistance value (0.5 weight) - 10K, 100R, 4.7K, etc.

Maximum similarity is 0.8 (not 1.0) since tolerance and other specs aren't always extractable.

Applicable Types

ComponentType.RESISTOR
ComponentType.RESISTOR_CHIP_VISHAY
ComponentType.RESISTOR_CHIP_YAGEO
ComponentType.RESISTOR_CHIP_PANASONIC
ComponentType.RESISTOR_CHIP_BOURNS
// Any type starting with "RESISTOR_"

Similarity Scoring

Condition	Score
Same value, same package	0.8
Same value, different package	0.5
Same package, different value	0.3
Different value, different package	0.0

Value Extraction

The calculator extracts resistance values from MPNs:

MPN	Extracted Value
`CRCW060310K0FKEA`	10K (10kΩ)
`RC0603FR-0710KL`	10K (10kΩ)
`ERJ3GEYJ103V`	10K (103 = 10×10³)

Package Size Extraction

Common package codes in MPNs:

Pattern	Package
`0603`	0603 (1608 metric)
`0805`	0805 (2012 metric)
`1206`	1206 (3216 metric)

Cross-Manufacturer Matching

The calculator can match equivalent resistors across manufacturers:

// Vishay 0603 10K vs Yageo 0603 10K
calculator.calculateSimilarity("CRCW060310K0FKEA", "RC0603FR-0710KL", registry);
// Returns >= 0.5 (both are 10K, may have same package)

Test Examples

// Same Vishay resistor - max similarity
calculator.calculateSimilarity("CRCW060310K0FKEA", "CRCW060310K0FKEA", registry);
// Returns 0.8

// Same value, different package
calculator.calculateSimilarity("CRCW060310K0FKEA", "CRCW080510K0FKEA", registry);
// Returns 0.5

// Same package, different value
calculator.calculateSimilarity("CRCW0603100RFKEA", "CRCW060310K0FKEA", registry);
// Returns 0.3 (100R vs 10K)

Implementation Notes

Returns 0.0 for null MPNs or null registry
Returns 0.0 for empty strings
Handles unrecognized formats gracefully (returns 0.0-1.0)

Learnings & Quirks

Value Notation

E96 notation:
```
103
```
= 10×10³ = 10kΩ,
```
4R7
```
= 4.7Ω
Yageo TCR code
```
-07
```
is NOT a separator, it's temperature coefficient

Package Extraction

Some MPNs embed package in series name (e.g.,
```
RC0603
```
)
Others have separate position (e.g.,
```
CRCW
```
+
```
0603
```
)