similarity-connector

name	similarity-connector
description	Use when working with connector similarity calculations - comparing connector MPNs, understanding pin count/pitch/family matching, or connector-specific similarity logic.

Connector Similarity Calculator Skill

Guidance for working with ConnectorSimilarityCalculator in the lib-electronic-components library.

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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

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Overview

The ConnectorSimilarityCalculator compares connectors based on:

• Family - Connector type/series (must match)
• Pin count - Number of contacts (must match for high similarity)
• Pitch - Contact spacing
• Mounting type - Through-hole vs SMD
• Series compatibility - Within TE, Molex, etc.

Applicable Types

ComponentType.CONNECTOR
ComponentType.CONNECTOR_MOLEX
ComponentType.CONNECTOR_TE
ComponentType.CONNECTOR_JST
ComponentType.CONNECTOR_HIROSE
ComponentType.CONNECTOR_AMPHENOL
ComponentType.CONNECTOR_HARWIN
// Any type starting with "CONNECTOR_"

Returns false for null type.

Similarity Thresholds

HIGH_SIMILARITY = 0.9;   // Same series, same pin count
MEDIUM_SIMILARITY = 0.5; // Compatible but different
LOW_SIMILARITY = 0.3;    // Different pin counts

Key Rules

Family Must Match

Different connector families always return 0.0:

// Different families = incompatible
calculator.calculateSimilarity("TE-connector", "Molex-connector", registry);
// Returns 0.0

Pin Count Rules

// Same pin count required for high similarity
calculator.calculateSimilarity("10-pin", "10-pin-variant", registry);
// Returns HIGH

// Different pin counts = LOW
calculator.calculateSimilarity("10-pin", "20-pin", registry);
// Returns 0.3

TE Connectivity Connectors

Part Number Format

1-292161-0
│ │      │
│ │      └── Configuration/variant
│ └─────────  Series number
└───────────  Prefix

// Same TE series
calculator.calculateSimilarity("1-292161-0", "1-292161-2", registry);
// Returns 0.9 (same series)

Würth Headers (WR-PHD)

// Compatible header variants
calculator.calculateSimilarity("61300411121", "61300411021", registry);
// Returns 0.9 if same pin count

Similarity Building Blocks

When connectors aren't direct variants, similarity is built from:

• Same pin count: +0.2
• Same pitch: +0.2
• Same mounting type: +0.1

// Compatible characteristics
// Same pin count (+0.2) + Same pitch (+0.2) + Same mount (+0.1) = 0.5

Connector Handlers

The calculator uses specialized handlers:

• TEConnectorHandler
• MolexConnectorHandler
• JSTConnectorHandler
• etc.

These extract:

• getPinCount(mpn) - Number of contacts
• getPitch(mpn) - Contact spacing (mm)
• getMountingType(mpn) - THT/SMD
• getFamily() - Connector family name
• getVariant(mpn) - Specific variant
• areCompatible(mpn1, mpn2) - Direct compatibility check

Test Examples

// Same TE connector
calculator.calculateSimilarity("1-292161-0", "1-292161-0", registry);
// Returns 1.0

// Same TE series, different variant
calculator.calculateSimilarity("1-292161-0", "1-292161-2", registry);
// Returns 0.9

// Different families
calculator.calculateSimilarity("TE-part", "Molex-part", registry);
// Returns 0.0

// Null handling
calculator.calculateSimilarity(null, "1-292161-0", registry);
// Returns 0.0

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Learnings & Quirks

TE Part Numbers

• Format often: X-XXXXXX-X or XXXXXXXX
• Series number is key to compatibility
• Last digits often indicate configuration

Molex Part Numbers

• Often 10+ digits
• Series embedded in part number
• Configuration codes vary by series

Metadata-Driven Implementation (January 2026)

Status: ✅ Converted (pre-existing)

The ConnectorSimilarityCalculator uses a metadata-driven approach with ConnectorHandler integration.

Specs Compared

Spec	Importance	Tolerance Rule	Description
pinCount	CRITICAL	exactMatch	Number of pins (MUST match)
pitch	CRITICAL	exactMatch	Pin spacing (2.54mm, 1.27mm, etc.)
family	HIGH	exactMatch	Connector series/family
mountingType	HIGH	exactMatch	THT, SMD, Press-fit

Implementation Pattern

// Different families return 0.0 immediately
if (!handler1.getFamily().equals(handler2.getFamily())) {
    return 0.0;
}

// Extract specs using ConnectorHandler
int pinCount1 = handler1.getPinCount(mpn1);
int pinCount2 = handler2.getPinCount(mpn2);
double pitch1 = handler1.getPitch(mpn1);
double pitch2 = handler2.getPitch(mpn2);

// Weighted spec scoring
// pinCount: CRITICAL (1.0 weight)
// pitch: CRITICAL (1.0 weight)
// family: HIGH (0.7 weight)
// mountingType: HIGH (0.7 weight)

Key Feature: Handler-Based Extraction

Unlike other calculators that use regex patterns, ConnectorSimilarityCalculator uses ConnectorHandler implementations for accurate spec extraction.

Why more accurate: Connectors have complex MPN formats that vary by manufacturer. Using handlers ensures correct extraction of pin count and pitch.

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Pin Count Extraction

• Critical for compatibility
• Different manufacturers encode differently
• Some require handler-specific logic

Pitch Variations

• 2.54mm (0.1") - Standard through-hole
• 2.00mm - Common header pitch
• 1.27mm (0.05") - Fine pitch
• 0.5mm - FPC connectors

Mounting Types

• THT (Through-Hole Technology)
• SMT/SMD (Surface Mount)
• Press-fit
• Wire-to-board