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🔗 Series Resistance Finder

Find the best E-series resistor pair to match a target series resistance.

Search Parameters

📏 Selected Series Pair

Resistor R₁
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Resistor R₂
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Series Result (Center)
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📊 Matching Error
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⚠️ RSS Error
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⚠️ Worst-Case Error
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📈 Total Effective Range (Matching + Tolerance)

RSS Method (Statistical)
Minimum Possible Value
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Maximum Possible Value
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Worst-Case Method (Conservative)
Minimum Possible Value
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Maximum Possible Value
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📋 Candidate Pairs

Click any row to see detailed error analysis above

How It Works

Series Resistance Formula: Rtotal = R₁ + R₂

Error Analysis:

  • Matching Error: How closely the series combination matches your target
  • RSS Error: Statistical error from component tolerances (√(ΔR₁² + ΔR₂²))
  • Worst-Case Error: Maximum possible error (|ΔR₁| + |ΔR₂|)
  • Total Effective Range: The actual possible range considering both matching error and component tolerances

Example: Target 1kΩ with 1% resistors → Best pair: 470Ω + 470Ω = 940Ω
Matching: -6%, RSS Tolerance: ±1.41% → Total range: -7.41% to -4.59% (925.9Ω to 954.1Ω)

R₁ R₂ Matching Error
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