How Capacitors Work: A Simple Explanation

5. How to Read Resistor Values

Most fixed resistors use color bands to indicate their resistance value.
The bands represent digits, multipliers, and tolerance.

Example:
• Brown → 1
• Black → 0
• Red → ×100
• Gold → ±5% tolerance

This corresponds to 1,000 Ω (1 kΩ) ±5%.

SMD resistors use numbers instead:
• “103” = 10 × 10³ = 10 kΩ
• “472” = 47 × 10² = 4.7 kΩ

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6. Applications of Resistors

Resistors are used in nearly all electronic devices. Common applications include:

Current Limiting

Protect LEDs or other components from excessive current.

Voltage Division

Create adjustable or fixed voltage outputs using a voltage divider.

Pull-Up / Pull-Down Resistors

Used in digital circuits to ensure stable logic levels.

Filtering

When paired with capacitors or inductors, resistors form filters for audio, power supplies, and communication systems.

Biasing

Set the correct operating point for transistors and amplifiers.

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7. Why Resistors Matter

Resistors seem simple, but they are essential for:
• Protecting sensitive components
• Ensuring accurate circuit operation
• Reducing noise and improving performance
• Controlling signal levels

Whether in consumer electronics, industrial automation, or automotive electronics, resistors are everywhere.

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8. Final Thoughts

Resistors are foundational components in electronics. By understanding their function, types, and applications, engineers and buyers can make more informed decisions when designing, sourcing, or replacing parts.