1. What is Capacitor ESR?

Equivalent Series Resistance (ESR) is an important parameter in capacitors that represents the sum of all internal resistances in series with the capacitor. It affects the capacitor's performance in high-frequency applications and power supply filtering.

2. How Does the Calculator Work?

The calculator uses the ESR equation:

Where:

• \( DF \) — Dissipation factor (unitless)
• \( f \) — Frequency in Hertz (Hz)
• \( C \) — Capacitance in Farads (F)
• \( \pi \) — Mathematical constant (~3.14159)

Explanation: The equation shows that ESR is inversely proportional to both frequency and capacitance, while directly proportional to the dissipation factor.

3. Importance of ESR Calculation

Details: ESR affects capacitor performance in circuits, particularly in power supplies and RF applications. Lower ESR generally means better performance, less heating, and longer capacitor life.

4. Using the Calculator

Tips: Enter dissipation factor (DF) as a unitless value, frequency in Hz, and capacitance in Farads. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical ESR value for capacitors?
A: ESR varies by capacitor type. Electrolytics might have 0.1-10Ω, ceramics 0.01-0.1Ω, and film capacitors 0.001-0.1Ω.

Q2: Why does ESR matter in circuits?
A: High ESR can cause excessive heat, reduced filtering effectiveness, and in switching power supplies, can lead to instability.

Q3: How does frequency affect ESR?
A: ESR typically decreases with increasing frequency up to a point, then may increase again at very high frequencies.

Q4: Are there limitations to this calculation?
A: This is a simplified model. Actual ESR may vary with temperature, age, and operating conditions of the capacitor.

Q5: How can I measure ESR directly?
A: Specialized ESR meters or impedance analyzers can measure ESR directly at specific frequencies.